Desktop CNC advice request

[wildbill]

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.

[ballscrewbob]

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.

[DangerToMyself]

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.

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.

[ballscrewbob]

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

[DangerToMyself]

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.

[ballscrewbob]

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.

[DangerToMyself]

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.

[ballscrewbob]

The more you use it the more you will need those switches.
Has to be the single best mod you can add.

[DangerToMyself]

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.

[ballscrewbob]

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.

[DangerToMyself]

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. 

[ballscrewbob]

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.
But sometimes I do wedge shaped parts so it may well be something worth my time looking at.

Bob.

[DangerToMyself]

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.
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


Image "borrowed" from http://www.scorchworks.com

[ballscrewbob]

See now the student teaches the teacher LOL.
You got my attention.

Bob.

[ballscrewbob]

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.