Mill DRO using rotary encoders and Android for an interface

How's everyone doing? I'm new to the Arduinos and to this forum. I need a little guidance on what I need to get. I came across a PDF document from the Home Metal Shop Club that has some go info. But I want to check and make sure that there's not something a little more up to date. I found this document very interesting. Because back in the day. I made an interface board which connected to the incremental rotary encoders (3600 P) then the parallel port of my PC. I found a program that a guy on the internet shared. Hi s name is Art Eckstein. I believe he did create the program which is DOS based. Which works great. But my computer is getting old and takes up some room. So with all of that being said any info and/or help would be greatly appreciated. The encoders are 3600 resolution. I'm redoing how they are attached and driven/actuated by the machine. This will be done by a GT2-3M timing belt attaching at both ends of each axis. Then the encoders will have a 20T pulley and this will be part of an assembly which will be placed mid point of each axis. I can later attach some sketches if anyone is interested in my plan.

Thanks,
JuniorC

So the encoder will make 1 turn for 60mm travel? What is maximum traverse speed?

I found the text in the Original Post almost impossible to understand because several ideas seem to be jumbled together. A little bit of white space makes things much easier to absorb - like this

How's everyone doing? I'm new to the Arduinos and to this forum. I need a little guidance on what I need to get.

I came across a PDF document from the Home Metal Shop Club that has some go info. But I want to check and make sure that there's not something a little more up to date.

I found this document very interesting. Because back in the day. I made an interface board which connected to the incremental rotary encoders (3600 P) then the parallel port of my PC.

I found a program that a guy on the internet shared. Hi s name is Art Eckstein. I believe he did create the program which is DOS based. Which works great. But my computer is getting old and takes up some room.

So with all of that being said any info and/or help would be greatly appreciated.

The encoders are 3600 resolution. I'm redoing how they are attached and driven/actuated by the machine. This will be done by a GT2-3M timing belt attaching at both ends of each axis. Then the encoders will have a 20T pulley and this will be part of an assembly which will be placed mid point of each axis. I can later attach some sketches if anyone is interested in my plan.

Am I correct to think that you have a working DOS based system using a program that you got from the Internet some years ago and you would like to replace it with a newer program that can work with a new PC?

But I am not clear whether the Home Metal Shop PDF relates to your existing working arrangements or whether it is a new idea that you think might be a basis for your new system. If the latter then a link to it would be a good idea.

And I am not clear what help you are looking for from us? From a computing point of view the mechanical arrangements by which the encoders are connected is irrelevant.

Are you thinking of using an Arduino to count the pulses from the rotary encoders? If so it would be useful to have a link to the datasheet with the technical data for the encoders..

Where do you want the displayed position data to appear - will it be on a PC? If so, what PC program will be displaying the data? Do you plan to write the PC program yourself? Or use an off-the-shelf program?

...R

Sorry for everything being all jumbled up.

Yes I have an old DOS based DRO program on an old computer. I would like to do away with the computer.

I would like to build something similar to PDF document from Home Metal Shop.

What I’m looking for from this forum is which Arduino do I need and how hard is it to program to read the encoders and also to communicate with an Android tablet.

Yes I want the Arduino to read the encoders.

The encoders are Hengstler RI41-O/3600AR.11KB. I will attach the info for the encoders.

I know there will have to be some changes to the encoder count. Do to the 20T pulley being attached to the encoder.

I want to display the data on an Android tablet.

I would like to program the readout. But I’m not sure how difficult it would be. I have CNC programming experience and some PLC programming experience. Not sure how this would relate to programming an Arduino.

So if need to be I’m game for an off-the-shelf program. If there’s one available.

Again sorry for the jumbled confusion. I tend to ramble sometimes. Hope this makes a little more sense.

Thanks again for the help.

JuniorC

Datasheet_RI41_en.pdf (231 KB)

JuniorC:
Sorry for everything being all jumbled up.

Yes I have an old DOS based DRO program on an old computer. I would like to do away with the computer.

I would like to build something similar to PDF document from Home Metal Shop.

What I'm looking for from this forum is which Arduino do I need and how hard is it to program to read the encoders and also to communicate with an Android tablet.

Yes I want the Arduino to read the encoders.

I want to display the data on an Android tablet.

So if need to be I'm game for an off-the-shelf program. If there's one available.

JuniorC

I used the same program for many years on an old milling machine here.
Still have it running on both my miniature cam grinding machine and the crankshaft grinder, the latter running on a freeware pc PLC.

They all used mouse encoders geared up through sync belts to give some decent resolution but it always had a couple of small drawbacks on the mill.

One being the backlash calculations were never completed before the project writer abandoned it and as the encoders were driven from the x and y advance wheels, one always had the start with the "thread ' wound up in one direction. Z was no problem.
Worked really well and dead accurate.

I looked at using a freeware bluetooth program with my encoders and actually built all of the boards and did some preliminary testing and then changed my mind and installed Chinese dro with slider encoders on the table.(too many projects and not enough time)

Link to Yuri's Dro just be prepared to do a lot of reading. There seems a lot of ways to get to the info you need on this site.

Edit:- one thing you may have to watch is the encoder resolution. At 1 turn for 60mm seems way too low. There are reasonable quality linear encoders available now in all lengths ranging from 100 or 200mm upwards to over 1 metre at fairly cheap prices.

I'll check that website out.

I told you all the wrong pitch. I'll be using a GT-2M . Which is a 2mm pitch.

I can get the pulley as small as a 15T.

And if I calculated correctly 15T@2mm pitch and a 3600 pulses per revolution. That should give me an accuracy of .00033". Does this sound correct.

Thanks again for everyone's help.
JuniorC

JuniorC:
I would like to build something similar to PDF document from Home Metal Shop.

Please post a link to that PDF. Otherwise I have no idea what you have in mind.

By the way, why not just buy a modern DRO and attach it to your mill?

...R

Here the link.
www.homemetalshopclub.org/news/17/android_dro.pdf

I have the encoders and an old Android tablet. Also it's just an old bench top mill. Not wanting to spend a bunch on a store bought DRO.

I also thought if this would work and learn a little on how the Arduinos works it would be a plus.

Thanks again for your time.
JuniorC

JuniorC:
Here the link.
www.homemetalshopclub.org/news/17/android_dro.pdf

I have the encoders and an old Android tablet. Also it's just an old bench top mill. Not wanting to spend a bunch on a store bought DRO.

I also thought if this would work and learn a little on how the Arduinos works it would be a plus.

Thanks again for your time.
JuniorC

Your link was the same "Yuri's Dro" as I referred to.

mmm...if you have the encoders, that's half the battle ( or rather cost)
being rotary might be a bit of a challange though (had experience with that before)

As Robin2 says, a store bought Dro might be a better alternative.
Cost is relatively low these days for the readout at around $150.00 for 2 axis and only maybe $10 more for 3 axis.

Having just bought one some 6 months ago I can say they are great and packed with many features.

Complete unit for my mill was around AU$350.00 complete with linear encoders, brackets , leads, the lot.
Had to make some of my own brackets to suit the mill but they are essentially just a basic kit for all comers.
Would take a LOT of programming to get to that level.

Still, with the Yuri unit most of that has been done and there are alternatives for all sorts of encoder types already factored in. Just have to choose which.
It uses the MSP430 Launchpad( was when I had some thoughts along that way) and there is an amount of building /programming involved.

From a very quick skim through that PDF it seems to have nothing to do with Arduinos and is mostly dealing with hardware stuff like soldering connections and very little to do with software.

From a quick look at the encoder datasheet I reckon they can be used with an Arduino.

You did not answer an important earlier question (in Reply #2)

Where do you want the displayed position data to appear - will it be on a PC? If so, what PC program will be displaying the data? Do you plan to write the PC program yourself? Or use an off-the-shelf program?

...R

Bluejets,

Where did you purchase your DRO's

Robin2,

I would like for the displayed position data to appear on an Android tablet.

There's an Android app (touchDRO) that displays the data.

I'm thinking the only thing that needs programmed is the Arduino

Thanks again,
JuniorC

JuniorC:
There's an Android app (touchDRO) that displays the data.

We need to know the technical details of how to get data to the touchDRO program.

...R

From what I can tell it's done via Bluetooth

JuniorC:
From what I can tell it's done via Bluetooth

Correct.
Dro project starts here.

One downloads the app to an Android device and assembles/programs the other hardware.

As I said earlier , it covers many different aspects and different hardware etc.

From memory there was an Arduino version.

Arduino version here

If I was to purchase an Arduino to see what I can do. Far as get a DRO to work.

Is the msp430 launchpad okay to use or is there a specific Arduino that would be recommended?

Thanks,
JuniorC

I think probably any Arduino would be ok but if you read through the link on the Yuri site for the Arduino model I'm sure there will be some reference there.

Not sure if the MSP430 has been superseded or not.
It has been a while since I went though all the details.
Fairly certain the MSP430 had a lot more options regarding encoder type.

It would be fairly simple to load up the Arduino program he supplies and pump it through a bluetooth module to your Android and see what comes up.
Cost would be fairly low for a bluetooth module and clone Arduino.

I appreciate all the help you have given me. I'll research Yuri site some more and go from there. Once I get a few things established I'll post some pics.

Have a great day.

JuniorC