Arduino Forum

Using Arduino => Motors, Mechanics, Power and CNC => Topic started by: DangerToMyself on Oct 21, 2019, 04:59 pm

Title: Desktop CNC advice request
Post by: DangerToMyself on Oct 21, 2019, 04:59 pm
This topic was originally placed in the "General Discussion" forum and has since been moved.

I've been wanting to get in to CNC machining for a few years now. I'm a hobbyist woodworker and DIYer and having the ability to make more intricate parts would make some of my ideas easier to accomplish. And, I'd like to possibly produce my own PCBs some day.

Eventually, I would like to have a larger stand alone machine capable of handling a 4' sheet of plywood. And who knows? Maybe even design and build my own. But for now, I think a smaller unit would be better for me at this time due to space limitations, etc.

I'm still in the process of researching machines. So, if you have experience with one or more of these small machines, feel free to tell me about it. Pros, cons, etc. I'm looking for machines capable of working with wood and plastics. Machining aluminum would be a plus. But in no way a "requirement".

I would really like to hear from anyone with advice on the software side to use on a Linux based computer. There are vast amounts of information available on Winblows based programs. But it seems most of what I'm finding about Linux programs is just lists of what's available. Or Joe Schmoe raving "X program is the best", without really telling why he thinks that way.

And if you have any good links to useful resources, feel free to reply.

Thank you for your time!
Title: Re: desktop CNC advice request
Post by: Robin2 on Oct 21, 2019, 06:38 pm
I would really like to hear from anyone with advice on the software side to use on a Linux based computer.
This a Forum for helping people with their own Arduino projects. It is not a Linux forum.

I suspect you will get a lot more help on some of the many CNC forums.

Are you aware that there is a program called LinuxCNC ?

...r
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 21, 2019, 07:19 pm
If you are going to buy a small machine off the shelf so to speak please make sure there are NO 3d printed parts involved. You may have to pay a little extra for such a machine but you will thank me later LOL.

Once you get above a certain size the G-CODE control mechanisms change from mostly GRBL based to MACH based.

However once you have played with a smaller machine moving up to a MACH based machine is quite a short learning curve as you will already have most of the basics down pat.

Better also to avoid those that have the Arduino NANO based control board approach and go for the UNO based.

Currently use my stuff mostly on hardwood so I know if I slow them down even just a small amount they would also be fine for Aluminium.

Don't know what your budget is but a decent size laser of 5W or greater is a fantastic addition and opens up the machine to a lot of new areas.

Don't use Linux here so cannot say much in that aspect.

Bob


This pic might get your juices flowing LOL
(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=329297)
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 21, 2019, 07:32 pm
This a Forum for helping people with their own Arduino projects. It is not a Linux forum.

I suspect you will get a lot more help on some of the many CNC forums.

Are you aware that there is a program called LinuxCNC ?

...r
This is why I asked in this part of the forum. After all, it's description is
Quote
Feel free to talk about anything and everything in this board.
The many CNC forums you speak of are typically geared toward professionals ( or at least seem to be ) with high end machines. I've not, to this point, found one that has a section for hobbyists/noobs that really gets any traffic. For instance, the one I found this morning. The last post/reply was back in May of this year.

As for LinuxCNC, I have seen mention if it in my research. However, most, if not all, I've read on it were sales pitches, for lack of a better term.

I will indeed seek more information on that particular program. Thanks!
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 21, 2019, 07:50 pm
If you are going to buy a small machine off the shelf so to speak please make sure there are NO 3d printed parts involved. You may have to pay a little extra for such a machine but you will thank me later LOL.

Once you get above a certain size the G-CODE control mechanisms change from mostly GRBL based to MACH based.

However once you have played with a smaller machine moving up to a MACH based machine is quite a short learning curve as you will already have most of the basics down pat.

Better also to avoid those that have the Arduino NANO based control board approach and go for the UNO based.

Currently use my stuff mostly on hardwood so I know if I slow them down even just a small amount they would also be fine for Aluminium.

Don't know what your budget is but a decent size laser of 5W or greater is a fantastic addition and opens up the machine to a lot of new areas.

Don't use Linux here so cannot say much in that aspect.

Bob


This pic might get your juices flowing LOL
(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=329297)
Thank you very much!

I had read elsewhere to avoid machines with 3D printed parts. But nothing I have read has explained why. I can assume that it has to do with the parts being too flexible or break/wear out.

I had no clue there was a need to use Mach for larger machines.  I figured that the computing would be pretty much the same regardless if size.  But there will time to figure that out later.

And the laser is something I have thought about. And I may go that route to start with in my learning process. Just thinking with a laser there are no expensive cutters/bits to break!

Did you make that clock? Awesome!
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 21, 2019, 08:08 pm
Are you aware that there is a program called LinuxCNC ?
Just went to the LinuxCNC website. Looks like I have some reading to do. Thanks again for bringing it up. Not sure why I had not went to the source on that one until now.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 21, 2019, 08:11 pm
Dang...
I knew you were going to ask a couple of "WHY ?"

OK the 3d parts from China and most others will fail for a few reasons.
Infill not sufficient
Cheapest plastic used for the extruder or even re-used plastic used to make the plastic.
30-60% less compression strength.
There are more but those are the main reasons to avoid 3d parts.

As for GRBl to MACH it is pretty simple and more to do with power requirements and motor drivers.
You would be taking that big leap from hobby to semi pro and looking for longer term durability.
That said I probably have a few thousand hours on my hobby machine and the same on the two laser based home brew machines (printers and plywood and chewing gum approach).

Lasers can bring thier own minor issues in that FLAT OBJECTS are mostly the the things you can do until you get into 4th axis or fancy surface tracking. (can be a steep learning curve)

Yes The clock is only one of many wonderful objects I made that keep the wife gasping and allowing me to spend so much time with Arduino and my machines. It was simply a combination of open source artwork / clipart put together in a couple of hours and then machined into a chunk of red maple.

Bob.
Title: Re: desktop CNC advice request
Post by: Robin2 on Oct 21, 2019, 08:29 pm
However once you have played with a smaller machine moving up to a MACH based machine is quite a short learning curve
Just out of curiosity did you use GRBL or MACH3 to make your clock face?

It seems to cost money and I can't find out how you interface it to hardware - presumably it is just a tad more modern than LinuxCNC and is not expecting you to have cobweb infested PC with a parallel port :)

...R
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 21, 2019, 08:33 pm
Yes The clock is only one of many wonderful objects I made that keep the wife gasping and allowing me to spend so much time with Arduino and my machines. It was simply a combination of open source artwork / clipart put together in a couple of hours and then machined into a chunk of red maple.
I still think it's awesome. More evidence to support the "Happy Wife = Happy Life" rule!

PS.
Thanks for the explanations!!
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 21, 2019, 08:42 pm
Hi R2.

Was going to ask how you are doing with your set up.

I have not yet made the move to MACH based machines but am pretty close as I need a larger machine.
But currently all done using GRBL based machines.

All the simple UNO with a CNC shield on top.
Gone through about 5 driver boards but almost all of my own stupidity by hogging down the machines.
But they are pennies anyway really.

I have a copy of ARTCAM (now defunct) that makes most of the work easy to do simply based on artwork.
There are a few open source packages but I have taken to this pretty well and it came with the first machine I got off the shelf so not looking a gift horse in the mouth.

Most of the newer MACH is USB based or you can even step it up to standalone too.
We all find different packages more to our liking for ease of learning.
I know you like your linux and I like my windows.

Bob.

Side note for Danger is that with cheap diamond bits from China you can also lightly engrave on stone ! Or with a 10/15W laser also write directly on quite a few types of stone.

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=329305)
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 21, 2019, 10:24 pm
Side note for Danger is that with cheap diamond bits from China you can also lightly engrave on stone ! Or with a 10/15W laser also write directly on quite a few types of stone.
Hadn't even given working with stone a thought. That's pretty cool though. I'll keep that in mind. Thanks for sharing.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 21, 2019, 11:05 pm
@Danger.

WARNING...These things can get very addictive and almost any object within arms reach can become a target for these little machines...."I wonder IF.....Oh I know what would be pretty cool to do...Hey just stick your hand on here for a few minutes....Oh I saw some wooden skids just down the road i will be right back...Hmmm now how can I modify this little $#!% to make it work better.

Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 21, 2019, 11:13 pm
Dang it ballscrewbob!

I'm over 50. Bladder control isn't a problem yet. But ya ain't gotta test it like that! That was friggin funny.
Title: Re: desktop CNC advice request
Post by: Robin2 on Oct 21, 2019, 11:20 pm
Was going to ask how you are doing with your set up.
As usual I got sidetracked. I have spent several very enjoyable weeks building a Python program that is a GUI front end for the OpenSCAD 3D modelling program. Unless you use OpenSCAD I doubt if it will have any interest but there is a short video here (https://youtu.be/q1Sd0Fuppuw).

...R
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 22, 2019, 02:30 am
Oh and did I mention making paint stencils with the laser.

(https://i.ytimg.com/vi/u1mOXYrJ7ck/hqdefault.jpg)
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 24, 2019, 07:53 pm
Well, in my search for a decent machine, I am really leaning towards the MillRight M3 (https://millrightcnc.com/product/millright-cnc-m3-kit/) minus the Router and mount. I really don't want to use a wood router to do the job of a spindle. Not to mention the noise a wood router makes. I know spindles can be loud as well.

Anyone heard anything bad abought the M3? Or with MillRight in general? Not real keen on the frame being made of MDF. But that could be upgraded later on to something more durable and stiffer.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 24, 2019, 09:38 pm
Not keen on the belt drive either to be honest or the Vee rails.
(explanation) Real CNC machines tend to always use direct drive or a small pulley to direct drive not a full belt for the whole travel. It is also less noise overall too. Also there is no SLACK to take up that can introduce some positional errors.

If that's about the size you want to start with then I would say look for something that has direct drive from the stepper and runs on at least 12mm linear rails. (most about that size will)

I know the chinese ones look crappy but the frames tend to be aluminium and very sturdy.
The "TEE" bolt frame can take many additions and  lend themselves well to modifications (speaking from experience LOL)

Mine has had some plywood added and an extra PSU for the better spindle and some extra controls are mounted on that along with fans (old computer) on each side in PUSH PULL mode to get the fumes and fine dust to one side for easier clean up...

I agree on no router approach for the smaller machines as the spindles are quieter.
But you should look for a minimum 500W (300W would be an ok starter) with an ER11 collet on it.
And ER11 chucks up to 1/4 and 6 MM although you would find a lot of the smaller bits use 3.175 mm regardless of size.  You WILL break some of the smaller tools until you get to grips with speeds and feeds so having extras is a bonus.

Don't expect to use STD router tools on small stuff unless you are quite careful.

Mine is a bit of a Frankenmill with the modifications but it does what I ask of it and I can swap it back to its original config without too much hassle apart from the Y and Z axis that failed (3d printed).

Bob.

Addendum.. In another life I installed ballscrews to CNC lathes and mills and was also a service tech for a couple of CNC machine suppliers hence the nic.
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 25, 2019, 01:31 am
Addendum.. In another life I installed ballscrews to CNC lathes and mills and was also a service tech for a couple of CNC machine suppliers hence the nic.
That makes me appreciate your insight all the more!

I looked at the Chinese CNC machines like this one (https://www.amazon.com/Upgrade-3018-Engraver-Controller-Extension/dp/B07DXMFY38/ref=mp_s_a_1_5?keywords=cnc+router&qid=1571958716&sprefix=cnc&sr=8-5).  And was putting thought into how to recreate those printed parts in a stronger material. Or how to swap them with better parts.

Aside from that, and the cheap spindle, those machines seem somewhat solid. There's even a vid on YT where a fella machines aluminum with his. No way near as fast as the MillRight M3 was shown to do though. That said, the MillRight had a top of the line spindle and a high quality mill/bit. (Still working on terminology)

The ability to machine aluminum is not mandatory for me. Just a bonus.
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 25, 2019, 02:16 am
The machine I linked above was not the one I was eyeballing. It has plastic uprights. This is similar or maybe even the same (https://www.amazon.com/Desktop-Control-Plastic-Engraving-30x18x4-5cm/dp/B07FY532DH/ref=mp_s_a_1_237?keywords=cnc+router&qid=1571961046&sprefix=cnc&sr=8-237) as what I was looking at.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 25, 2019, 06:20 am
Those grey plastic lumps are what will fail eventually.
Luckily for me I saw it coming and used the machine to make its own replacement parts somewhat.
A few suppliers offer upgrades to those parts and for the Z its often worth it as you will probably end up with more Z travel.
That extra Z travel can come in quite useful too.

If you have somebody who can machine HDPE or aluminium that would make great replacement parts.
If not and you are handy (and accurate) with wood then a suitable hardwood makes just as good a replacement.
My spare parts came from a hardwood skid and I used the machine to do most of the work but simplified that "U" shaped bit to just a block that carries the bearings and lead screw. Then added two right angle plates I found at the hardware store to carry the rest of the assembly.

But see all those empty T slots on the side that just beg for something to be mounted like a nice piece of ply so you can move the power supply and electronics to a better area and give yourself room to add some extra controls and gadgets.
Also acts as a guard sort of to keep a lot of the sawdust more inside the machine.

Mine was a 3025 with a 50mm Z now its a 3025 with 170 Z and a plethora of electronic bolt ons.
Once you have one in your hands then you will quickly see which bits could have been made better or what you need to add on.

BTW if you can be patient enough with waiting times for delivery then look at Aliexpress  (https://www.aliexpress.com/wholesale?spm=a2g0o.productlist.0.0.73464021dLurnr&SearchText=3018%20cnc%20upgrade)or even Ebay as Amazon tends to be more expensive for this game all round. Even my tooling comes from Aliexpress.

For tooling try avoid dual flutes and go with 4 flute preferably without the hole in the end for coolant and if you can find them the ones with slightly offset cutting edges on the bottom.
I got some 4mm ones a while back and am amazed at how much deeper I can go for a pass and how much quicker too. Not broken one of those yet either...Rough out with end mills and finish off with a ball end.
Although on occasion I finish with 1.0 mm END mills but you have to be careful with those.

BTW despite my CNC background it was all mechanical and I never programmed them so all this was a learning curve for me.

Will throw a couple of pics up when I get a moment that may explain better than I do.

Bob.

Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 25, 2019, 12:37 pm
I was actually contemplating using epoxy resin to cast blocks large enough to machine down. Stuff sets hard as a rock and cuts and drills pretty well. Would have to test if a 3018 can mill it though. I guess a lot would depend on the spindle and tooling chosen.

I linked to the one on Amazon only because their links tend to stay active longer. eBay  was where I was looking though. And you're correct. Much cheaper.

And I would love to see how you modded the Z axis. The Z travel is IMO the one of the biggest cons to these machines besides the plastic bits. Of course, my opinion is based on very, very limited knowledge.

Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 25, 2019, 04:53 pm
Some poor pics of the mods.

The black brackets found at a hardware store. The lower one was modified to allow the spindle body to pass by

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=329849)

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=329851)

Extra parts used.

2x optical rod 8mm x 200mm long
2x flange mount for 8mm rod
2x end mount for 8mm rod
1x  8mm leadscrew 250 mm long
1x 8mm flange bearing.

Rest was scrounged from the Z failure.
You can also see some rubber strip I used to help damp the spindle noise but that has to be positioned carefully otherwise you will throw out the the tooling alignment.
Just had enough room on the machine to get most of the depth needed for the bearing holes etc in the wood with a long series 6mm end mill, and finished off on a regular drill stand.

Other pic shows the plywood dust catching and fan.
It will take two fans if I want as there is a plate over the second hole.

I would be wary of EPOXY RESIN as it has a tendency to fracture under stress. You will encounter stress in more than one way LOL.

Bob
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 26, 2019, 01:03 am
I would be wary of EPOXY RESIN as it has a tendency to fracture under stress. You will encounter stress in more than one way LOL.

Bob
I really should have thought of that. I built an electric guitar for my son last Christmas and finished it with clear epoxy. Makes for one heck of a mirror shine when all buffed out. But he bumped it pretty hard going through a doorway and it popped a big chunk out. Was a pretty easy repair. Way easier than a paint finish.

I'll probably start out similar to yours by using a hard wood. Once I figure everything out I should say.

Just did the "make offer" thing on a 3018 on eBay. Have to wait and see if they'll go for it. Their original price was well below anything on Amazon. And I asked for another 30% off. We'll see.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 26, 2019, 06:00 am
30% less I would consider a bit of an insult so don't be surprised if you don't get an answer.

Good thing is the machine is capable of making its own spare parts in some cases.
Better thing is, you can design them without the flaws and some built in improvements.

There are some advantages to using hardwood on these smaller machines.

1. If you use the GRAIN to its advantage it can add quite a bit of strength.
2. It does help soak noise and vibration.
3. The size you are using makes it super cheap and affordable. (or in my case free)
4. Easy to make even if you don't have the machine to begin with. (my prototype was just done on the drill)
5. This is an important one. As you use grease to keep the bearings lubed that soaks into the wood and enhances the strength even more as it feeds the wood (so to speak)

Bob.


Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 26, 2019, 06:07 pm
Quote from: ballscrewbob
30% less I would consider a bit of an insult so don't be surprised if you don't get an answer.
I heard back on that offer. Person said listed price was the price. No negotiating. Replied back with a higher price and asked why have that option available. Got a reply stating it would be removed from future postings.

Going to order one that doesn't come with the ER11 collet. But I'm also going to order a better spindle. Seems most of those I'm finding come with the collet.

I'm open to input on what to look for in a decent spindle. Of course, an ER11 is pretty much mandatory. And bare minimum of 300W. But looking for 400+.

Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 26, 2019, 06:10 pm
Also, regarding the use of wood to recreate/modify the plastics. Thinking about using plywood layered together. That should take care of strength in just about every direction. Plus, I have plenty on hand. Thoughts?
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 26, 2019, 08:18 pm
Decent plywood properly laminated and glued etc would be a great substitute for just hardwood.
Probably marine grade as the glues used are better than regular ply.

Last spindle I got was this one (https://www.aliexpress.com/item/32341330193.html?spm=a2g0s.9042311.0.0.27424c4dDeC9zK).
Love it and extended the pot wires a bit so I could place it better.
Also fitted a proper switch rather than the wire jumper for on/off.
Bonus is that it will drop in to a larger machine because it has the MACH option too.
Sort of thinking ahead of myself LOL.

Bob.
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 26, 2019, 09:25 pm
Last spindle I got was this one (https://www.aliexpress.com/item/32341330193.html?spm=a2g0s.9042311.0.0.27424c4dDeC9zK).
That is weird. The one you have linked is one of two I have in my cart. The other one is roughly the same price but doesn't have nearly as much with it. Just the spindle, collet and driver. And now that I'm looking at them side by side, I think they're exactly the same driver and spindle. So, I guess it's a no brainier on which to delete from my cart. Still eyeballing others but seems like best bang for the buck. And most likely the one I'll order.

As I said, I really do appreciate you sharing your opinions/knowledge. I feel a lot more confident that I won't be just wasting money on something completely unusable.

I'm going to place my order today for the machine and the spindle and possibly a bit set. I think that should keep me busy for a time with delivery time, setup, etc.

I'll hit up LinuxCNC for software questions. And with any help I need getting it to actually mill a project.

 Hopefully, I won't have to bug you for a while!

Thanks again!
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 27, 2019, 12:04 am
As for the mill set Might I suggest.

A couple sets similar to these. (https://www.aliexpress.com/item/32799176806.html?spm=a2g0o.productlist.0.0.20c56ec6xUjXyk&algo_pvid=74fd954c-318b-46ee-b945-b9acf73bcc94&algo_expid=74fd954c-318b-46ee-b945-b9acf73bcc94-10&btsid=e01b2437-e08c-475e-9f5b-eeb136b1aec0&ws_ab_test=searchweb0_0,searchweb201602_1,searchweb201603_55)

And a couple sets of these. (https://www.aliexpress.com/item/32954054350.html?spm=a2g0o.productlist.0.0.65e17873fJCK9X&algo_pvid=84e73b9e-9a0b-47e7-a87b-11bdf2002345&algo_expid=84e73b9e-9a0b-47e7-a87b-11bdf2002345-36&btsid=46ad6f3a-354a-4e76-8618-41be7ae3fc85&ws_ab_test=searchweb0_0,searchweb201602_1,searchweb201603_55)

Between them you would have a good starter set suitable for a good range of work.

You can always add to those later with more specialist ones.

Bob.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 27, 2019, 12:07 am
As for bugging me well thats what we are all here for one way or another.
Masochistic tendencies I think they call it LOL

Bob.
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 27, 2019, 04:28 am
As for the mill set Might I suggest.

A couple sets similar to these. (https://www.aliexpress.com/item/32799176806.html?spm=a2g0o.productlist.0.0.20c56ec6xUjXyk&algo_pvid=74fd954c-318b-46ee-b945-b9acf73bcc94&algo_expid=74fd954c-318b-46ee-b945-b9acf73bcc94-10&btsid=e01b2437-e08c-475e-9f5b-eeb136b1aec0&ws_ab_test=searchweb0_0,searchweb201602_1,searchweb201603_55)

And a couple sets of these. (https://www.aliexpress.com/item/32954054350.html?spm=a2g0o.productlist.0.0.65e17873fJCK9X&algo_pvid=84e73b9e-9a0b-47e7-a87b-11bdf2002345&algo_expid=84e73b9e-9a0b-47e7-a87b-11bdf2002345-36&btsid=46ad6f3a-354a-4e76-8618-41be7ae3fc85&ws_ab_test=searchweb0_0,searchweb201602_1,searchweb201603_55)

Between them you would have a good starter set suitable for a good range of work.

You can always add to those later with more specialist ones.

Bob.

Found similar end mills on eBay and have them on the way. However, my CC company locked my card down when I tried to order the machine and spindle from Banggood.  :smiley-mad: Hopefully I'll be able to get hold of them tomorrow and get it unlocked. Then get the rest ordered. Maybe I'll have it assembled before Christmas. I should probably start a PayPal account. Might make things simpler.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 27, 2019, 04:41 am
Not used bangood because of the same issue.
That's partly how I ended up on Aliexpress and never looked back.

Bob.

Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 27, 2019, 05:37 am
AliExpress is way too pricey on their machines. Either huge shipping amounts or they say free shipping and jack their price up when you click on USA. A 3018 on there would cost close to $200. About $150 on banggood.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 27, 2019, 05:46 am
Yes you have to watch the shipping but so far no problems.
Maybe you are getting hit by Cheetos Tariffs ?
And maybe I need to have another look at bangood ?

Bob.
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 27, 2019, 03:08 pm
Yes you have to watch the shipping but so far no problems.
Maybe you are getting hit by Cheetos Tariffs ?
And maybe I need to have another look at bangood ?

Bob.
Well, got the card straightened out and opened a PayPal account (I had no idea it was that easy to pay for stuff ). No issues whatsoever with my CC and PP. Payment is already pending on my bank account.

Got this spindle for $63.99

Machifit ER11 Chuck CNC 500W Spindle Motor with 52mm Clamps and Power Supply Speed Governor (https://www.banggood.com/Machifit-ER11-Chuck-CNC-500W-Spindle-Motor-with-52mm-Clamps-and-Power-Supply-Speed-Governor-p-1027937.html?cur_warehouse=CN)

And this machine for $132.99

3018 3 Axis Mini DIY CNC Router Standard Spindle Motor Wood Engraving Machine Milling Engraver (https://www.banggood.com/3018-3-Axis-Mini-DIY-CNC-Router-Standard-Spindle-Motor-Wood-Engraving-Machine-Milling-Engraver-p-1274569.html?cur_warehouse=USA)

I couldn't get anywhere near those prices at AliExpress. And the items I ordered are coming in from Canada and should arrive in the next 3 or 4 days. The best AE could say on a delivery date was by 12/31.

So, for my case (this time) Banggood was the cheapest and quickest. Even besting eBay in both categories.

I ordered the Machifit collet set separately on eBay for $7 or $8 w/free shipping. 2 each of mill end sets similar to those you suggested for about $16 shipped. and 5 KW12-3PCB limit switches for $4 shipped.

With any luck, by this time next year, I'll have a fully operational battle ..... er .... CNC machine for approx $230. Cheaper than I had imagined. But I'm also aware there is more cost to come. LoL Like that laser!

(It's hard to say "fully operational" without going full Emperor Palpatine)
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 27, 2019, 04:39 pm
I remembered the other reason I didnt use Bangood was that they didnt have the larger machines.
Probably to keep shipping costs down.

Did notice some cheaper and some more expensive items so may have to pick and choose where I buy.
Already have PayPal from my Ebay days so not much to do or change.

I still run without limit switches but I should take the time to go that path and certainly will when I order the bigger machine.


Small list of SPARES or other goodies that are GOOD TO HAVE ON HAND.

8mm Bearings (flange) Same as on the machine (x2).

8x5 Coupling for the lead screws ( x2)

Assorted TEE nuts and TEE bolts to suit the different slots on the machine. Also useful for clamping purposes.

A spare controller (UNO and Shield) I got a few now but one set may save your bacon. And at about $8 CDN for a set it is not really wasted money and also provides a nice test bed. Also DRIVER BOARDS but pay the few cents extra for the higher duty ones. and always get them with heatsinks and be prepared to put a small fan nearby too aiming at them (longer term reliability)

Some small momentary push switches for use as the PAUSE RESUME and ABORT that you can mount in easy reach. (you may already have or can salvage) and SHIELDED cable to use with them. Old PS2 keyboards are great for that cable. Also some suitable DUPONT connectors if you don't already have some. I invested in the proper crimp tool a long time ago for regular Arduino work.

Suitable ON / OFF switch for the PSU's

Suitable ON/OFF switch for the spindle.

Digital Vernier, even a cheapish one will be fine. (at least 10 inch). Used to fine tune the alignments of the whole machine and keep track of tool sizes and a multitude of other odd machine related jobs.
Also a good 6" and 12" rule with imperial and metric scale.

Couple of spare stepper leads (invaluable in the long term)

At least one spare stepper motor. Also useful for testing but you may find at least one goes down on you if you stall them too often.

A decent terminal block to help with wire routing and keeping things simpler in the longer term as you add extra controls circuits etc. Also very useful for the STAR grounding you will need to employ when you are adding switches and such.

I also keep a spare 24v 15A PSU on hand.

IMPORTANT spares are the bearings. You only need the bearings which will probably be 12mm and 8 mm LM xx UU types. At least 4 of each size. You will probably need those at around 500 + hrs as you will have bumped the machine a lot by then if you are as foolish as me (I bet it can dig another couple of mm from this cut..Oh dang maybe not)

Some light grease EP2 or Lithium white. I use the white. to PRIME the bearings before installation.

A decent set of long reach ball end allen keys for those hard to reach places and better than the cheap bendy ones supplied with the machine.

A good selection of small washers and lock washers for use during installation. If you are a millwright you will notice a few places where none are included in the kit but as an engineer you will tell yourself that it needs one. You may also notice that that parts of the machine will benefit from the extra MM or so clearance especially the bed to the rod carriers. The kit will be mostly OK but a bit sparse in some areas. Also useful helping spread load for clamps and such.

A very understanding partner who is prepared to listen to you prattling on about parasitic noise on switches and why you crashed your machine and now need X amount of money to order Y part.

You don't need all those at once, and they are not in any particular order except that last one which is pretty critical but all worthy spares one way or another.

Loved the Star wars reference.
Prefer the HOLD MY BEER AND WATCH THIS approach myself.

Bob.

Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 27, 2019, 05:06 pm
And....

Be prepared to DEDICATE some tools to the machine such as the rulers and 6" and 12" tri square.
Maybe  some screwdrivers, small spanners (wrenches to the heathens).
Decent stanley knife (box cutter to the uninitiated).
Small plier set.
A multimeter (almost any cheap DVM will do)

A dedicated tool / shadow board comes in handy with room to expand.

Bob.

PS. did I mention the all forgiving partner ?


Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 28, 2019, 01:09 am
Small list of SPARES or other goodies that are GOOD TO HAVE ON HAND.
That seems like a pretty comprehensive list. Thanks again! A few items I had thought about. Most I hadn't. All of which makes perfectly good sense though. A few items I'll get right away and then add the others over time to break up the expense.


A very understanding partner who is prepared to listen to you prattling on about parasitic noise on switches and why you crashed your machine and now need X amount of money to order Y part.
I have the luxury of only having to answer to myself.

But I will do some homework on "parasitic noise on switches". Wasn't aware that could be an issue though.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 28, 2019, 01:14 am
Side note to all this.

Finally fixed my parasitic glitches after a week of minor cable re-routes and upgrades.
Had gotten it down to just random PAUSE.

Step 1. Enclose cable runs individually in screening (old coax with centre removed is great for that). Heat shrinked the ends so it looks tidy.

Step 2. Route USB cable at diagonals to any cable crossing (old trick but works).

Step 3. Ferrites wherever possible at the ends of cable runs (all scavenged from misc electronics).

Step 4. Make and install a 0.47 electrolytic capacitor pack into a 4 way DUPONT header that goes to a set of ground pins, and feed other ends via some super soft thin stranded cable to the signal side of the switches. Also heat shrunk the cap pack.

Step 5. 10nF disc cap near spindle and another at the other end near the PSU.

Step 6. 10 nF cap across the spindle relay output.

4 hours dry run and not a single glitch.
Sounds like a lot of work but hope I can go back to a "lights out" approach at last.
Next test is actual cut and its will be in fully cured ELM so it will have its work cut out for it.

This thread gave me the impetus to get around to this job so thanks guys.

Bob.

PS as I hit post it told me you had just posted LOL.

Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 28, 2019, 02:04 am
We all need a little push every now and then!

And your last post tells me I have a lot to learn about knocking down noise!

Need more coax? I think I still have a box of coax (probably 450' left in it ) out in the shed. I found it on the back porch of an abandoned house on a job site when I was a land surveyor several years ago. I may have to have you tell me how you removed the center. Just trim the outer layers back a little leaving the center core longer and then grab it and pull it out?

Side note to all this.

Finally fixed my parasitic glitches after a week of minor cable re-routes and upgrades.
Had gotten it down to just random PAUSE.

This thread gave me the impetus to get around to this job so thanks guys.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 28, 2019, 02:12 am
Yep that's pretty much how I did it but in about 2 foot lengths otherwise it will be a problem. (learned that the hard way)

And well on my way to adding limit switches too now...Dang you....LOL

Bob.
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 28, 2019, 02:26 am
And well on my way to adding limit switches too now...Dang you....LOL
You're welcome!  8) LoL 8)


And take pictures!!! I may need visual reference.
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 28, 2019, 06:04 pm
Well, so much for saving a few bucks. Banggood cancelled my order. Guess I'll be paying a little more over at eBay.

Banggood sent me an email saying they needed me to send them a copy of my driver's license to verify I am who I say I am. Seriously? As if I'm even going to give a single thought to actually doing that.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 28, 2019, 06:07 pm
Hmm no way do they need that.


Bob.

Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 29, 2019, 04:39 pm
The machine should arrive in 2 days. Along with some of the "add ons". Hopefully I'll be able to at least start the assembly process this weekend.

I've been thinking on the whole shielded wires thing. Is there a down side to using shielded guitar cable? Not sure the gauge on each of the (I believe) 4 individual wires and won't til I'm home. I have several feet of fairly high quality not being used (yet).
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 29, 2019, 04:50 pm
So long as it is shielded (prefer braid over the cheap plastic foil) then it should be fine for such as the PAUSE, ABORT, RESUME, or limit switches.

As for the steppers and spindle (my next task) or other electronics then keep it at the very least the same gauge or if you can the next one up.

Bob.



Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 29, 2019, 10:59 pm
Moving this to motors and mechanics.
Simply because it may help others who don't get this far down the sections.

@R2 I should have listened to you earlier LOL (Dang did I say that out loud)...Shh voices in my head be quiet now this wont hurt a bit.

Bob.
Title: Re: desktop CNC advice request
Post by: DangerToMyself on Oct 30, 2019, 01:46 am
You have shared a bunch of info. Would be a shame if I were the only one to benefit from it.

And I'm sure, as I dive head first into this, that you'll be sharing some more! I know I'll need it.
Title: Re: desktop CNC advice request
Post by: ballscrewbob on Oct 30, 2019, 02:18 am
May also be nice to get some critique as to where I might have gone wrong too.

None of us are perfect least of all me.

Bob.

Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Oct 30, 2019, 02:38 am
Oh and it took me 4 hours to complete the mechanical build for the one off the shelf.
I full expect that to be beaten.

Then on the initial build about 1 hour for the wiring to switch on.
Again I know that can be beaten.

Bob.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Oct 30, 2019, 02:57 am
You asked for some extra pics.
One badly shows a ferrite and I used the shielding to run a ground to the speed control case but it also (sort of) shows the heat shrunk end.

Other is the new CNC test board.

If I suspect a part is dead I can swap it out against a known working one.
Used the spare 24V PSU I had.
The relay (almost centre) is for spindle control but will be adding another for fan control too.
You can see I also mount the heatsinks with the fins in the same direction so the tiny fan (far right) pushes air over easier.
Two chinese voltage droppers also employed. One gives me the 5V i need for the relay and the other gives me the 12V I need for the fan.
You can also see the shielded cable running to the main switch box.
Push buttons for the GRBL functions and the ability to switch the 5, 12, or 24V lines off individually too. (power all kept to one side of the box.

Mounted on a bit of ply so I can move it around or if needed use it as a full backup control system by simply swapping wires over.

Bob.

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=330583)

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=330585)
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Oct 30, 2019, 12:33 pm
I like the idea of a test board. Easier to figure out what might be wrong and you know you have the part.

I'll be putting one of those together after I get my head wrapped around what I have coming now.
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Oct 31, 2019, 01:44 am
The machine I ordered has the control board mounted vertically. I think you mentioned adding heatsinks to the stepper modules as has everything I've read about them. And I see them in your pics.

Being vertical, is it best to use thermal paste? Or go with a glue or tape? My brain says glue or tape. But other than being somewhat permanent, I really don't know what other cons may be lurking for a noob such as myself.

I guess the only reason I would ever want to remove them would be if a module died. Then it wouldn't matter at all if I damaged the module removing the heatsink.

Did I just talk myself through that?
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Oct 31, 2019, 02:16 am
To use paste you would need retaining clips and there is no provision on the boards I have seen for that.

The glue on tape can become soft with heat and the heatsinks can be jostled around.

I went with superglue and have not yet had any heatsink failures.

And yes you talked to yourself a lot I heard. ... JK.

Bob.

Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Oct 31, 2019, 03:38 pm
Final part of my parasitic jigsaw.

Now running total "lights out" with zero issues.

Run the motor case ground cable back to the spindle PSU case where I have my star ground located.

Bob.

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=330791)
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Oct 31, 2019, 06:33 pm
I went with superglue and have not yet had any heatsink failures.
Super glued parts can be separated with heat. Although, if one of those modules gets that hot, you have bigger problems. Super glue it is then!

Is the green wire the ground you speak of? Looks like you added that. Grounding that to the power supply really help that much?
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Oct 31, 2019, 06:53 pm
Or you can buy a bag of 20 of those heatsinks without the adhesive tape for about $1.00 CDN !

Grounding motor cases is a common enough practice anyway even in industry.
In my case it helped and in your case it is easier to do during the machine build.
getting it to follow my add-on drag chain was fiddly.

A machine FRAME ground is also a useful addition.

You can always include it in the spiral wrap too.

Bob.

Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Oct 31, 2019, 07:13 pm
Just for a little bit of reference.

(https://i.stack.imgur.com/JRky1.png)
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 01, 2019, 12:10 am
Thank you ballscrebob! For clearing up the "Star grounding". I assumed that is what you meant by that. But me and any form of the word "assume" don't tend to get along.

Got my machine today. Couldn't help but do a rough assembly without any add-ons or mods. Wasn't able to get the Y-axis table mounted. The screws are about 2mm too short. So, have to head to the hardware store tomorrow. Aside from that, it went together pretty well. (If someone is thinking about a machine like this and CAN'T assemble something like this without directions, don't purchase a Chinese 3018 CNC. There are no directions for these things).

Planning to install limit switches, of course. The board only has sockets for 3 (x,y and z). So, I'll have to double up if I want them on both ends of an axis. The board says "www.benbox.ca" on it. That's really the only markings that might point to more information. Haven't checked it though.

Going to stare at it for a few hours and decide what kind of mounts I need to make for the limit switches. Figure out how to run the wires and secure them. Etc, etc, etc.

Also, I ordered a machine that was shown with and came with the brass 8mm to 6mm (I think) shaft connector for connecting the bit/mill. However, to my amazement, it came with an ER11 already attached to the motor.

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=330920)
(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=330922)

I'll have to cut these down just a bit. Dremel to the rescue!
(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=330924)
(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=330926)
(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=330928)
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 01, 2019, 12:30 am
See that stick up MOSFET...See if you can mount a heatsink on it but bigger then the driver board ones.
Probably nothing to worry about but if it were my machine I would feel a little happier.

Not sure if you may have already checked the tracking for the X and Y ?
If not remove the steppers and slide the assembly to the very end of each direction to make sure there are no tight spots. If there is then slacken off two mounts on one bar and let it relax into position while sliding back and forth. Oh and of course check it is still parallel to the frame.

The closer you get those parallel movements the more accurate your corner cuts will be.
Otherwise you will probably cut a slight diamond shape.
Used the digital vernier here for most of that work.

When the table is on you can use that as the ZERO to set the Y rails to run true to the table.

Once it is completely built go around every nut, bolt, screw and double check they are tight.

You look to be doing well there young padawan  :)

Bob.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 01, 2019, 01:06 am
.
You look to be doing well there young padawan  :)
Padawan.... Sure. Young.... I wish!!!

I'll be taking the machine completely apart and reassembling it after doing some cleaning and burr removal. I'll be measuring everything very carefully then.

I put the X guide rods and lead screw through the Z assembly. Mounted the top rod on both ends. Slid the Z to one end and tightened the bottom rod there. Slid it the other way and tightened the bottom there. Moves from one side to the other smooth as silk.

I have a few heatsinks I harvested from here and there. I'll see if one will fit in there with that MOSFET. Appreciate the tip.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 01, 2019, 01:28 am
62 but feel 30 ISH most days.
Some days maybe not so much.

Don't forget to pump as much grease as you can into those linear bearings prior to final assembly.

Never used those 3d printer bearing holders I see for the lead screw so have no idea how long they will last.
I would suggest using a drop of loctite or similar on them during the build too.

Not spotted anything else too obvious.

Once it is fired up properly you may want to check the GRBL version on that Nano and go with 1.1F (current version) But you would need to also make sure your shield is capable too as some of them needed a special version of GRBL to get around a PCB wrong track issue.
Chances are it will not affect that one though.

Bob.
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 01, 2019, 01:50 am
Well, I guess you have a few years on me then. 50 here.

I've been trying to find info on the board. Turns out it is a " Alfawise CNC Laser Engraver Main Board - Ruby Red"

Specs/Description...

Chip: 328P
Product name: 3-axis control board ( compatible with Y-axis dual motor control )
Main control module: NANO 328
Interface: USB
Rated input electrical parameters: 12V - 36 V, 6A
Support system: XP / Win7 / Win8 / Win10
Support software: GRBL / LASER / CANDLE / BENBOX
Supportable axis: 3 axes
Spindle interface: 2 pins
Laser interface: 3 pins
Power interface: DC 5.5 x 2.5
Is there an external water cooler: yes
Whether to support two-needle laser: yes
Whether it has an external 24V terminal: yes


Now, I know you're not a Linux fella, but what are the odds this board will run with Linux? Seeing as it only mentions WinBlows.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 01, 2019, 02:16 am
Chances are exceptionally good.
In fact probably better than that even.

All you are going to do is send GRBL commands to the board via USB and the board will do all the fancy shenanigans to make things wiggle around like you tell it to.

What you use for that is almost entirely up to you.
Ya can get fancy schmancy Like Robin and make your own or pull from about a dozen or so packages off the Linux shelf.

Bob.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 01, 2019, 02:52 am
Yeah. That agrees with what I've been reading since I asked. It's all new to me.

I just have to figure out the processes for the tasks I want to accomplish. The program's I want to use for each step of the process. Etc. There's a LOT to learn.
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 02, 2019, 06:20 pm
Hey ballscrewbob (and anyone else who has one of these machines). Just for future information. Not sure what size extrusions your machine uses. Mine are 20mm. And an M5 hex bolt (with just a wee bit of grinding) fits in the slot. Might be useful in areas where you don't care if the threaded end is sticking out a bit.

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=331177)
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 02, 2019, 06:29 pm
There are a few sizes that will fit in there with just a tiny amount of modification.

Some "dome head" bolts are also good as the short square section under the head can stop them spinning.
Different parts of the extrusions will take some useful bolts for "add-on's" < had to be careful typing that.

Bob.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 02, 2019, 08:06 pm
There are a few sizes that will fit in there with just a tiny amount of modification.

Some "dome head" bolts are also good as the short square section under the head can stop them spinning.
Different parts of the extrusions will take some useful bolts for "add-on's" < had to be careful typing that.

Bob.


I didn't even give lag bolts a thought. I may have to pick some of those up (if I don't have them already). Have to go back to the hardware anyway. My dumb butt forgot the longer M6 bolts to mount the table. And that was the main reason for going!
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 03, 2019, 06:58 pm
Ok FINAL MOD.

A DIODE.

As close to the spindle motor as possible between the Ground and the positive rail.

Did get two totally random glitches over the last two days (thought i was past that)
Cause was pretty clear as it only happened when it had finished a cut and was heading home.
Only thing that happened at that point is the spindle turns off and even then it did not always do it.

Diode types may vary depending on the voltage and amps a specific spindle pulls.
In my case a 10A10 works like a charm. A little overkill but a very easy mod often mentioned when dealing with motors.
It should prevent the spike back when the voltage is cut off.

9 hours, 4 cuts and not a peep.

Have a few diodes from board tear downs and such so was ZERO cost.

Bob.
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 03, 2019, 09:50 pm
That on the 500w motor?

My machine made its first movements today. Working on brackets to hold the limit switches. With that in mind, the big orange box hardware store sells shielded 18g 4 wire for $0.66 per foot. Picked up some today for my limit switches. Possibly a little overkill.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 03, 2019, 10:48 pm
Yep that was on a 500W spindle.

18G might be a little tricky to get into dupont connectors.
Shielded cat 5 or 6 might be a little better then you also get the twisted pair scheme to help things a little more.

Bob.
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 04, 2019, 07:33 pm
Well, I haven't had a great deal of time to mess around with the new toy. But I have made some progress. It's together as far as I can get it until other supplies come in the mail. I've only had time to get  the limit switches mounted. 2 for X, 2 for Y and 1 for Z.

The X and Y mounts were pretty straight forward. It took some "out of the box" thinking to get the Z switch in place though. A few pics for anyone interested.


The X and Y switches are all mounted similar to this, the left X switch. And those M2 bolts will be turned around so they won't be poking outward.
(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=331527)

Yes, bending that thing was a pain in the caboose!
(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=331529)
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 06, 2019, 10:18 am
Guess what grandpa knocked up after the postman came with goodies....
Looks familiar but it isn't !
GRBL running on the MEGA with a RAMPS 1.4 !

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=331779)
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 06, 2019, 06:21 pm
Guess what grandpa knocked up after the postman came with goodies....
Looks familiar but it isn't !
GRBL running on the MEGA with a RAMPS 1.4 !

That's awesome. Send me the other board you put together and I'll hold on to it for safe keeping. I've got some extra space for storage :D

Now clue me in on the Ramps 1.4.  A cursory glance at Google makes me think it's main use is a fan controller. But don't have a lot of time to study on it til later.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 06, 2019, 07:04 pm
Send you the other one...Yeeaaa Suuuure...And your cheque is in the post too   :)  :)

Ok this Ramps thing is new to me too so I may get some things wrong.
Literally jumped in the deep end yesterday.

HOWEVER...

Allows pendants external controls and displays and has some nice mosfet included outputs, along with lots of spare pins to add a whole slew of goodies
The TWO spare AXIS I can see being quite useful in the not too distant future.

Buffer space is MASSIVE compared to the UNO / NANO types which may be either a bonus or a pain...Not sure yet.

It did take a little while to find a suitable GRBL firmware though so lots of swearing and uploads involved.

It cost me a little over $4 for two Megas and a little over $5 for for the Ramps board so outlay was certainly worth it in my case as a progression step in my skills (few that they are LOL).

Bob.


Title: Re: Desktop CNC advice request
Post by: wildbill on Nov 06, 2019, 10:22 pm
I've used Ramps to drive a 3D printer, which is what it was originally for I think. So it can handle four steppers, some limit switches, heated bed, extruder temperature and fan. But no doubt different firmware can adapt it easily to CNC needs.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 07, 2019, 12:24 am
Hi Bill.

That's what really surprised me.
Most of the forks had ceased work about 2 years or more ago in the GRBL side of things.

I had expected there to be a much more active side.
The one I found that worked best is actually over 2 years old.

But thankfully it is pretty well documented and easily customisable too.
Works great with UGS too.

The UGS people also seem to have taken an interest in a good MEGA fork but not sure if it is RAMPS directed.

Bob.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 07, 2019, 01:31 am
Anyone looking for a CAD program to go along with their CNC, I have a recommendation.

Just download FreeCAD. I have years of experience with CAD programs (mostly AutoCAD in a civil engineering setting).  If you have little to no experience using those types of programs, get it and watch a few vids. It's by far the easiest 3d design program I've ever used.

Now, I may change my mind on that if it makes me jump through a bunch of hoops to get from finished drawing to useable g-code. :D

Haven't made it that far with it yet. But I did design an enclosure for the main board of my CNC that incorporates a PC fan. Took all of 45 minutes.

Now I just need to win the lottery so I can afford the acrylic to make it out of! I had no idea that stuff was made from the juice squeezed from gold bars.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 07, 2019, 02:34 am
Now I just need to win the lottery so I can afford the acrylic to make it out of! I had no idea that stuff was made from the juice squeezed from gold bars.
Same with decent epoxy in any sort of quantity.

I have a half decent selection of rocks with GOLD in them from some time building new gold mines in Northern Ontario but cant quite squeeze it out... Looks pretty though...buttery yellow not the shiney fools gold.

Prices on some materials is why I do so much upcycling of old printers, stereos, and such.
Fine source of bits and bobs.

I can often beat the garbage men on re-cycle day in my town.
Local dump is also exceptionally re-cycle friendly and if I don't like it I can always take it back for something better LOL
I go up there with a few tools drop off what I took then mooch around for an hour.

Bob
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 12, 2019, 04:01 pm
How's the machine working out Bob?

I'm still waiting for some items to be delivered before I can finish connecting all my switches and the like.

Was messing around with UniversalGcodeSender to set up the correct number of steps. Hit a button and the machine unexpectedly took off at an angle and down. Broke the tip off one of my cheap engraver bits and put a small gouge in the bed.

No idea what I did wrong. So, I can't say "I won't do that again".

And, for now, I've given up on using a Linux machine. I'm still learning my way around Linux and just starting to figure out CNC. Learning the two together would probably be a disaster.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 12, 2019, 06:04 pm
Mine has been running like a champ since my last modification.

Sort of wondered where you were.
Suspected you had it running and were bewitched watching a simple UNO do all that magic LOL.

Lots of people mount what is terms a "waste board" to the bed.
Something like 1/2" ply and use that as a bed.

Good thing about doing that is you can skim cut the whole machining area of the machine and it will be level to the gantry.

And if you allow extra at the side or end or both you have room to fit a fixed layer stop that you can also machine true to the X and Y axis.
If you do that I suggest pegs and screws then you can remove it if you want to drop a bigger work piece on.

Bob.



Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 12, 2019, 06:55 pm
Planning on using 1/4 MDF for the waste board for now. Probably go thicker once I change the Z-axis to something other than plastic and modify for a little more vert travel.

I could have stopped my goof if I had the stuff for my kill/pause/stop switches. But, it took me a second to find the button on the board mounted to the back of the machine. Stuff should be in this week though.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 12, 2019, 07:17 pm
The more you use it the more you will need those switches.
Has to be the single best mod you can add.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 15, 2019, 05:13 am
Well, I designed a little PCB for hooking up some of the wiring. So, I installed Python and bCNC so I could do auto-leveling if the PCB. Got that program working and figured out how to do the auto-leveling. Pretty neat.

Gave milling the board a go. First time through I noticed traces moved on the Y axis as though steps got missed. Stopped the process and went to looking for the issue.

One of the set screws on the Y axis coupler backed out. So I took all three couplers off and put thread locker anywhere I had missed. Which ended up just being the one set screw.

Attempt 2. The bit stopped touching the board about 45 seconds in. My dumb butt didn't check to see if the spindle was held in tight. Snugged the screw down. Powered it all off and walked away.

I'll go through the entire machine screw by screw tomorrow.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 15, 2019, 05:26 am
I think we covered the screw thing quite early on LOL
Don't feel bad I forgot to change a tool over today so I got another pass with a 4mm end instead of a 1.5 ball.

Looks a little odd in places but I will get it on the next pass.

Not really played with BCNC but it is installed...along with many similar programs I have moved away from.

Bob.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 15, 2019, 01:36 pm
I think we covered the screw thing quite early on LOL
Yes. Indeed you did mention that early on. Why I missed that one single set screw with the thread locker and didn't bother checking the spindle clamp screw, I'll never know. But I did. Which makes me wonder what else I missed. Therefore, checking EVERYTHING today. Twice!

Not really played with BCNC but it is installed...along with many similar programs I have moved away from.
As I think I mentioned, I am working on a little pcb and want auto-leveling. Apparently, that feature in GRBL isn't ready. Anyway, I got an alert to that effect when I clicked on the button. So, I made a very feeble attempt at figuring out ChiliPepper. I just haven't yet found the right documentation for me to understand how that program operates. I then stumbled upon some decent information on bCNC. Seems to do the job pretty well from what I can tell at this extremely early stage.

Do you do pcb milling with auto-leveling? If so, I'd be interested to know what program a professional, such as yourself, uses.  :smiley-mr-green:
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 15, 2019, 02:17 pm
Professional...LOL..Far from that.

I don't do PCB work so if I ever do I guess you will be my GOTO  :)

Almost exclusively art type work and almost exclusively wood. (https://www.facebook.com/groups/Accentricities57/)
But sometimes I do wedge shaped parts so it may well be something worth my time looking at.

Bob.




Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 15, 2019, 02:29 pm
Professional...LOL..Far from that.

I don't do PCB work so if I ever do I guess you will be my GOTO  :)

Almost exclusively art type work and almost exclusively wood. (https://www.facebook.com/groups/Accentricities57/)
But sometimes I do wedge shaped parts so it may well be something worth my time looking at.

Bob.





Well, auto-leveling isn't just for pcb making. Think of the possibilities

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=333149)
Image "borrowed" from http://www.scorchworks.com
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 15, 2019, 02:53 pm
See now the student teaches the teacher LOL.
You got my attention.

Bob.

Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 18, 2019, 05:05 am
A new bit of advice that may save you some money.

Unless you are 100% sure your spindle has no brushes (most of the Chinese adverts are false on this claim) then get some spare brushes...

Still working out my sizes which is a bit of a crap shoot LOL.

Spindle here slowly stopped and I figured it had just about had enough of my abusing it.
Stuck a 300w backup unit in to keep me going and ordered another 800w (dang good price so no real loss)

Thinking the slow one would be dead I stripped it down to find the brushes well past the sell by date.
It has had a hard life and something like 700 hours plus almost non stop apart from tool and job changes.

But looking like I will have two decent spares soon with a 500w and 800w on hand.

If you are only ever doing light work your hours will be much greater then mine but I was hogging out elm most of the summer.

Bob.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 26, 2019, 01:21 am
Well, after trashing a couple of cheap engraving bits and 3 or 4 smallish single sided PCB blanks, I have finally made my first creation with my machine. I had to fight through some parasitic noise. Twisted the crap out of all the wires and added some ferrite rings and ran a jumper from the case of the spindle to ground. Seems to be running "OK" for now.

The cheap spindle is not good at all. With both the cheap engravers that came with it and the more expensive ones I bought, just barely touching the surface of the copper will leave about a 0.5mm circle. Maybe not quite that big. But still larger than I feel it should. Hopefully, the larger spindle (once I build a mount) won't have that much slop.

Then came the next issue that had me scratching my head. My attempts would start out pretty good. But then as the bit moved to the right more and more, it raised above the surface. Every.....dang..... time. I was thinking the issue was bCNC. So, I started researching ChiliPeppr. And once I had it figured out. Same problem.

I finally had to start eyeballing my machine as the issue. So, I used the probe feature in ChiliPeppr and set Z zero on the left side of the gantry. Then moved it to the right side and probed it again. Bingo! Almost 2mm difference from one side to the other. That was one set of measurements where I didn't have a good way to measure them. So, I took a block of wood. Drilled a hole in it. And threaded a bolt into it. Set that under the right side of the guide rod and turned the bolt til it was just touching the bottom of the rod. Moved it to the left side and adjusted the height of the guide rods on that end.

The recheck with the probe now shows a 0.02mm difference from one side to the other!

And ..... Viola!
(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=334705)

I used one of the messed up boards. And have a few GND pads that ended up being isolated from the rest of the GND plane. Otherwise, I think it turned out not too bad. It's not professional. But you're not going to get that from me anytime soon!

I plan to redo it on a fresh copper. And I'm going to move the drill holes to the center of the pads. My reasoning for having them offset to one side was not well thought out :D

And don't go bad mouthing my HUGE traces! I have never done anything like this and was not sure what to expect. So, I went BIG! LOL
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 26, 2019, 01:35 am
I am impressed...
You will be spitting circuits out for fun soon.

You can see what I mean by lateral drift and runout on those cheap spindles.
They also burn out quite easily too as I don't think they have the duty cycle for most cnc jobs.

Having a sly giggle about your gantry issue...I wont say i told you so BUT.....
Hmmm now where was that cheap 10 inch digital vernier....
Oh wait that skimmed down wasteboard would have fixed that too...

Just kidding with yas ...
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 26, 2019, 01:59 am
I am impressed...
You will be spitting circuits out for fun soon.

You can see what I mean by lateral drift and runout on those cheap spindles.
They also burn out quite easily too as I don't think they have the duty cycle for most cnc jobs.

Having a sly giggle about your gantry issue...I wont say i told you so BUT.....
Hmmm now where was that cheap 10 inch digital vernier....
Oh wait that skimmed down wasteboard would have fixed that too...

Just kidding with yas ...

Dang it. I know you did!

I've got a vernier. And it wasn't until I just looked over at the machine that I figured out how I could have gotten it in there to take those measurements! But when I assembled it, I didn't see it. Wow. And it would have been so simple. Oh well. Not like I didn't already have thin and grey hair! My method worked pretty well though.

As far as a skimmed waste board. Just haven't wanted to take the time to do that part yet. I'll get to it soon though.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 26, 2019, 02:10 am
Grey is more colour than I have...

(https://i.pinimg.com/originals/f0/4e/32/f04e32d56da8859d364d1d8eb5eefcfb.png)
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 26, 2019, 08:13 pm
I took the week off. So, I have time to "play". Remilled the board last night. And started soldering things up this morning. And now I have a functioning limit switch board which incorporates LM187 optocouplers. I, also, added LEDs to help aide in troubleshooting later down the road when a switch, wire or the 5v supply inevitably goes bad. All lights out, no power from the 5v buck. One light out and no switches pressed, well, you get the point. And added another connection there for my probe. Not sure that's really needed. But figured it couldn't hurt.

(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=334855)

My circuit if anyone's interested
(https://forum.arduino.cc/index.php?action=dlattach;topic=642065.0;attach=334857)

And my complete lack of soldering skills will remain unseen. Completely embarrassing.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 26, 2019, 08:54 pm
Still just as impressed.

Few weeks ago you were not sure which way was up on these things.

We all just gave to the basics and the rest is all down to you.

Bob.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 26, 2019, 09:06 pm
Still just as impressed.

Few weeks ago you were not sure which way was up on these things.

We all just gave to the basics and the rest is all down to you.

Bob.


If you only knew how many times I have read through your advice! I have a bunch of your wisdom written in a notebook that I, for the life of me, can't seem to find. Along with pages of notes from all over the web. And 4 or 5 sets of step by step instructions hanging on the wall.

It's all part of dealing with a very bad memory. Some people's brains are like a well organized filing cabinet. They can pull out details from things they learned decades ago. My brain is closer to the city dump than a filing cabinet. The stuff is in there. I just need a map to find it. :D (i.e. my damn notebook)

And I owe you a huge thank you! Without the tutoring, I wouldn't be anywhere near being able to get this running.
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 27, 2019, 01:41 pm
Ok FINAL MOD.

A DIODE.

As close to the spindle motor as possible between the Ground and the positive rail.

Did get two totally random glitches over the last two days (thought i was past that)
Cause was pretty clear as it only happened when it had finished a cut and was heading home.
Only thing that happened at that point is the spindle turns off and even then it did not always do it.

Diode types may vary depending on the voltage and amps a specific spindle pulls.
In my case a 10A10 works like a charm. A little overkill but a very easy mod often mentioned when dealing with motors.
It should prevent the spike back when the voltage is cut off.

9 hours, 4 cuts and not a peep.

Have a few diodes from board tear downs and such so was ZERO cost.

Bob.

I know you used a 10A10 diode. I know I don't have any of those. I'll have to look through my scavenged parts bins to see what I can find. What characteristics am I looking for in a a decent diode for this purpose?
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 27, 2019, 04:27 pm
Mine was also a scavenged.

Based mine on a quick look up of the amps as I run a spindle controller PSU which can throw up to 50 volts when measured.

As a rule of thumb I would say (don't quote me) base it on the max amps and voltage available to that motor.
Also a small cap across the voltage rails for the spindle.
Google has lots of examples from 1Pf up to 10 uF I went with a 10 nF.

I will gladly accept better knowledge on this one myself.

Bob.
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 27, 2019, 05:09 pm
Hmm. Unsure (yet) what voltage my current controller spits out to the spindle. But, I just ran across a video of a fellow using the same 500w spindle I will eventually switch to. He was measuring the voltage output on it. At max RPM he was reading NEG 45 volts. And at low RPM he was reading POS 170 volts. I guess I'll need to eventually invest in some caps that can handle that sort of voltage.

If interested, link to vid (https://www.youtube.com/watch?v=bT1Bz6mDZeI). (He starts measuring about 1:50 in to the vid)
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Nov 27, 2019, 05:30 pm
Nice vid and good tip in checking and keeping the collets clean.

That said I have had a couple of bits that had run out regardless of the collet.

Those corn cob cutters are pretty neat as I have a couple here and they do work better on some materials but don't use them on plastic LOL...Ok go ahead and try it if you like the smell of molten plastic.

Most people use disc caps across motors not electrolytics.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Nov 30, 2019, 11:15 pm
Well, crud! Was running a little learning project earlier. All was going well until I look over and see smoke wafting up from behind the machine. Not sure what went. I can't "see" anything fried on the controller/Arduino. But I can no longer talk to the knock-off Arduino. So, guessing something on it let all the magic out.

Regardless, installed my back-up controller which uses an Uno and shield and does not have a plug to use the power supply that came with my machine. So, I have to figure out the best way to solve that issue. And then I think I'll be back in business.

Yay! China!
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Dec 01, 2019, 12:14 am
Seee...having that backup works great ...now you need to order a backup of the backup  :smiley-eek:  :D

If no clear signs of damage and works without anything else attached to it maybe just a driver popped.
If no worky at all on its own then El-Bin.

Order a batch / lot of UNO's sometimes even cheaper and you can never have enough arduinos   8)
5 for $15 inc shipping.

Bob.
Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Dec 01, 2019, 12:44 am
I've got 7 Uno boards. But I will need to order a few of the shields though.

Have to figure out what the deal is with this setup though. Got it all hooked up and powered it up. Then reconfigured the GRBL the way I "THOUGHT" the other was configured. But jogging 1mm goes waayyy further than a mm. And it goes about 90 mph to get there. Not to mention the grinding (for lack of a better word) sound it makes in the process.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Dec 01, 2019, 12:53 am
Sounds like the steps and acceleration figures are incorrect.

If its identical hardware just export the settings from UGS using the known good one and them import them into the dodgy one.

Power supply issues can also come into it too.

Bob.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Dec 01, 2019, 01:48 am
Sounds like the steps and acceleration figures are incorrect.

If its identical hardware just export the settings from UGS using the known good one and them import them into the dodgy one.

Power supply issues can also come into it too.

Bob.


Turns out this new stepper shield didn't have the jumpers installed for setting the micro stepping. Guess I should have pulled the A4988 modules off and looked under them. Live and learn. Properly jumped and seems to be working correctly again.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Dec 01, 2019, 01:55 am
Well that was an easy fix for you.

Got a ramps 1.6 on Friday so have some testing to do this week.
Hopefully my motor brushes come in too this week as it smells like a forest fire down here with the big laser running and I really need to get a spindle back up.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Dec 01, 2019, 02:09 am
Well that was an easy fix for you.

Got a ramps 1.6 on Friday so have some testing to do this week.
Hopefully my motor brushes come in too this week as it smells like a forest fire down here with the big laser running and I really need to get a spindle back up.


I have got to get me a laser! (I grew up on wood heat. I miss the smell of wood smoke in the air.).  All in due time, I suppose. Have to get where I can actually produce something with a spindle first.

My circuit I did had an issue I couldn't find. Think I possibly overheated one of the opto-isolators. Regardless, I have a revised version in the works. Hope I can do a better job soldering it though.


Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Dec 01, 2019, 02:10 am
I suppose I'll eventually look into upgrading from GRBL. So, learn all you can on the Ramps! I'll have questions one day :D
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Dec 01, 2019, 02:19 am
Ramps board will be commanded by GRBL but so far just on a test bed so no real action.

Didn't want to play around swapping parts out on the 1.4 board so got one that was 24 volt compliant already.
It will be driving some TB6600 drivers I have on my shopping list for some NEMA 23's also on my shopping list.

Bit of a hybrid machine in the planning.
All stock items so easy to repair or replace.

Want to retire one of the home brew to just laser work.

Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Dec 01, 2019, 09:31 pm
Hope the testing is going well!

Even with thread locker I can't seem to keep these couplers from loosening up during operation. So, ordered a new set of the clamping style. In the meantime, I'm going to tear my machine down (partially) to get good measurements on the Z axis parts. Need those to plan for getting rid of the printed parts when I upgrade to the better spindle.

Plus, I followed a video or two on how to assemble this thing. Seems those videos are wrong, IMO. With the way it's shown in photos and assembled in videos, the spindle is no where near the center of Y travel. Noticed that when getting full travel measurements for designing my waste board. Shouldn't be too difficult to remedy though.
Title: Re: Desktop CNC advice request
Post by: ballscrewbob on Dec 01, 2019, 09:40 pm
Yet the only issue I have had is when I trashed a couple by repeatedly banging it against one end.
Never had a loose one (she said)

On mine it was a X that wasn't quite right but that was just slacken two screws and move it in its slots for a few mm.

Yea a lot of the destructions have some issues...
Being a millwright I took some of them with a pinch of salt.

Not had chance to test, doing some jobs for the missus instead before I get frozen out of the garage.



Title: Re: Desktop CNC advice request
Post by: DangerToMyself on Dec 02, 2019, 04:18 am
In my reassembly to get the spindle centered, I found the issue with the couplers. At least the one that has been giving me fits. Which is the one on the Z axis. I removed that coupler and noticed that the lead screw it went to was nearly 1/8 inch higher than the motor shaft. So, there was some binding going on causing things to come loose. I added a spacer under the gantry where the lead screw mounts which got it closer to being aligned. It's not perfect. But better. I will measure everything ten ways from Sunday when I next have time to see if anything else is thrown off by that spacer. New couplers on the way are flexible. So, that should help as well.

I'll also add some pictures of how I changed the assembly to get the spindle closer to the center of the gantry in case someone else with a 3018 runs across this thread.