Author Topic: Isel CPM3020 cnc machine - electronics rebuild (Read 22863 times)

raynerd · « **on:** January 13, 2016, 06:12:10 PM »

I put a low bid in for a CPM3020 that had just come from a school closure and managed to win it. Photos were rubbish and I expected very little but it's German made, ball screws and a good solid heavy frame and case - I thought it was worth the money and based on eBay believe I could double the price I paid just chucking it straight back in in a cleaner state with better photos

Gave it a clean up just for my own piece of mind and I was chuffed with it:

Sadly, but as expected it's an old integrated driver board.

Just stripped it down further to find some usable stepper motors. So the next step is to strip out all the electronics. See if I am confident enough in keeping the PSU or maybe pull this out and replace but the drivers are going to need to be replaced that is for sure. Lots of work to do.... Oh heck, my Orrey project!!

tom osselton · « **Reply #1 on:** January 14, 2016, 12:10:11 AM »

Shouldn't be that bad cost wise, I'm just starting to collect parts for a cnc router. I bought ballscrews and rails off ebay (China) 300 x 900 x1150 along with the control board so I will be following your progress!

PK · « **Reply #2 on:** January 14, 2016, 05:25:00 AM »

At this scale, IMHO, it's hard to go past the G40 http://www.geckodrive.com/geckodrive-step-motor-drives/g540.html . Mainly because of the amount of fault protection it offers, but also because it's pretty much a drop in replacement for what you have...

philf · « **Reply #3 on:** January 14, 2016, 08:06:29 AM »

Quote from: PK on January 14, 2016, 05:25:00 AM

At this scale, IMHO, it's hard to go past the G40 http://www.geckodrive.com/geckodrive-step-motor-drives/g540.html . Mainly because of the amount of fault protection it offers, but also because it's pretty much a drop in replacement for what you have...

The downside with a unit like the G540 (other than price) is that it's not modular so if one component goes down the whole lot goes down. On the other hand it saves a lot of wiring and Gecko drives generally get good press.

Is it not possible to get the existing controller up and running?

Phil.

awemawson · « **Reply #4 on:** January 14, 2016, 08:34:24 AM »

There is a thread on CNC zone about resurrecting one of these machines:

http://www.cnczone.com/forums/techno-cnc/157780-cad-autocad-software-forum.html

and a load of information here:

http://www.spline.nl/machines/cpm.html#Booster

John Stevenson · « **Reply #5 on:** January 14, 2016, 08:35:09 AM »

Quote from: philf on January 14, 2016, 08:06:29 AM

Quote from: PK on January 14, 2016, 05:25:00 AM
At this scale, IMHO, it's hard to go past the G40 http://www.geckodrive.com/geckodrive-step-motor-drives/g540.html . Mainly because of the amount of fault protection it offers, but also because it's pretty much a drop in replacement for what you have...

The downside with a unit like the G540 (other than price) is that it's not modular so if one component goes down the whole lot goes down. On the other hand it saves a lot of wiring and Gecko drives generally get good press.

Is it not possible to get the existing controller up and running?

Phil.

Phil, they are modular, they hold 4 G250 drivers and you can swap them.

Only problem with these is by the time they get into the UK duty paid they are bloody expensive for what they are, a 3.5 amp drive which will be happier at 3 amp.
You could buy a USB breakout board and three 4.5 amp drivers for half the money.

More scope to use modern computers and a derated 4.5 amp driver is going to be far more reliable that a driver running at max.

philf · « **Reply #6 on:** January 14, 2016, 10:02:11 AM »

Quote from: John Stevenson on January 14, 2016, 08:35:09 AM

Phil, they are modular, they hold 4 G250 drivers and you can swap them.

Only problem with these is by the time they get into the UK duty paid they are bloody expensive for what they are, a 3.5 amp drive which will be happier at 3 amp.
You could buy a USB breakout board and three 4.5 amp drivers for half the money.

More scope to use modern computers and a derated 4.5 amp driver is going to be far more reliable that a driver running at max.

John,

Sorry - I thought it was an integrated control.

You're right - 4.5A drives are as little as £21 on eBay from China. (Just got to hope you don't get clobbered for VAT and the collection fee).

Am I still right in saying that you can't run a USB breakout board with Mach3? I know you can use a USB SmoothStepper but they don't come cheap either.

Phil.

raynerd · « **Reply #7 on:** January 14, 2016, 01:28:47 PM »

Hi, interesting posts. Sorry, but I'm staying away from Geko, they are just too costly especially with import and shipping. I'm sure they are good but can't see the benefit above 4.5a drivers or even a branded Leadshine DM556. Shine, these above nearly doubled since I lost got some...sure I paid £35-40 per drive from Arc Euro about six years ago.

It's a minefield but there is a lot of talk about motion control. Has anyone used these CSLABS I-PM
It's a heck of a price as well but MY UNDERSTANDING (!?) is that it acts as motion control and BOB all in one as is very good quality.

http://www.cs-lab.eu/en/produkt-18,2-CSMIOIPM_4axis_Ethernet_Motion_Controller_stepdir_with_connectors.html

Just to confirm, I need stepper drivers x3, motion control (or free parallel port!) and a bob to get this to move. Or I just need 3x drivers and then the CSLABS ip-m.

The PSU is 24.5v so I guess I can use this or should I really swap this out for 36vdc??

Ahhhh remember my last cnc build now. Heads going to explode.....

philf · « **Reply #8 on:** January 14, 2016, 02:19:11 PM »

Chris,

Since my last reply in which I asked about Mach3 with USB I have found two USB offerings from CNC4YOU both compatible with Mach3:

https://www.cnc4you.co.uk/Motion-Control

One looks like a USB to Parallel Port adaptor but it's a lot more than that and takes a lot of work from the PC by reading in the code and then dishing it out to the CNC. This might mean it would work OK from a laptop. I think you'd still need a BOB with this one.

http://cncdrive.com/MC/UC100%20datasheet/UC100%20users%20guide.pdf

The second looks more advanced and gives 36 outputs and 49 inputs + 2 analogue inputs + 2 analogue outputs and can handle 6 axes. You wouldn't need a BOB with this. [Edit: The manual says you should use a BOB with opto-isolation to protect the inputs. The stepper drivers usually have opto-isolation on its inputs.]

http://cncdrive.com/MC/UC300%20datasheet/UC300%20users%20guide.pdf

I bought all my drivers and motors from CNC4YOU.

Looks like they are available from elsewhere and good reports on both on the Machsupport forum:

www.machsupport.com/forum/index.php?topic=25448.0

Cheers.

Phil.

raynerd · « **Reply #9 on:** January 15, 2016, 11:11:38 AM »

On one of the cnc forums someone is really plugging the digital stepper drivers. Apparently the ones you linked to are analogue. However, for the extra money and the ability to buy them from the UK - I`ll go with the ones you suggested if you have been happy with them? I`d rather buy UK - estimated delivery for most China buys are between 6th and 28th Feb!

Any one else used the cnc4you 4.5A drivers or alternatives?

Chris

PK · « **Reply #10 on:** January 15, 2016, 03:59:36 PM »

The nice thing about the better drives (like the ones in the G540) is the amount of protection they have.
A broken wire to the motor, a short, an over voltage etc won't destroy them where as all of these things will reliably pop a cheap drive.

Add in step dithering and micro to full step morphing and they really are noticeably better. My mill has a Gecko drive on Y and that axis is faster than X (same motor, same voltage) and smoother at low speed.

I get that the cost is a big consideration, and I'm not trying to bash anyone over the head with this. Just thought it worth including in the discussion.

John Stevenson · « **Reply #11 on:** January 15, 2016, 04:30:53 PM »

The last generation of Leadshine drives also has the full step morphing and they also do closed loop steppers in either standard DC or three phase AC.
The three phase AC are virtually servo motors but without the hassle.

philf · « **Reply #12 on:** January 15, 2016, 06:08:15 PM »

Chris,

Have a look at www.estlcam.com.

Estlcam is a 2d/3d cam package but it also includes a CNC control to drive your machine directly (no need for Mach3 or LinuxCNC).

It uses an Arduino via a USB port to interface your PC to your CNC machine. All the Arduino programming is done automatically from within Estlcam.

A license for Estlcam is only 39 Euros!

Cheers.

Phil.

PK · « **Reply #13 on:** January 15, 2016, 10:07:20 PM »

Quote from: John Stevenson on January 15, 2016, 04:30:53 PM

The last generation of Leadshine drives also has the full step morphing and they also do closed loop steppers in either standard DC or three phase AC.

Didn't know that.. Good to hear.

Quote

The three phase AC are virtually servo motors but without the hassle.

Yeah, I got some NEMA23 three phase motors with a laser XY table kit I bought a little while back. I did a double take at the cables then went and bought the drives. Really looking forward to seeing how they go..

raynerd · « **Reply #14 on:** January 16, 2016, 05:54:46 AM »

Phil, I`m in no doubt that I`ll crack on and upgrade the drivers and have a more 'professional' system using Mach3 - however, I think I may well order the Leadshine drivers from China and in the mean time, I`d like to give Estlcam a go especially since I have an Arduino Uno kicking around somewhere, it won`t cost me a bean. However, to use it, I guess I`ll have to identify the step and dir for each motor - but after staring at the large board, I`m not sure what I'm looking for or where! Based on my previous experience of CNC, I think I`m right in remembering that there was a step, dir from the BOB. However, this is running serial cable in with only three wires from the PC output and then if there is a BOB built into the motor, no idea where to look.

Anyone any idea where I would tap into step and dir ?

awemawson · « **Reply #15 on:** January 16, 2016, 06:07:43 AM »

Chris,

Just guessing, but if it was RS232 driven, then the system board that you have probably receives G code, or a proprietary code, and drives the steppers directly. So you won't have an identifiable 'driver' that takes in step and direction, just a power stage for each winding of each stepper. This is likely an ic per stepper - probably with fins.

raynerd · « **Reply #16 on:** January 16, 2016, 09:30:27 AM »

Cheers Andrew. Just ordered stepper drivers, motion control and BOB so next step is removing all this existing electronics.

The PSU in here is 24.8v - is this good enough or do I need to swap out for higher voltage unit??

Joules · « **Reply #17 on:** January 16, 2016, 09:42:31 AM »

Chris, when you remove that controller can you have a look at the stepper chips and see if they happen to be Toshiba TA8435HQ's. It's a long shot but my old cnc router has blown one of those and I can't seem to find any. Thought it might be worth asking if you are just going to toss the controller.

seadog · « **Reply #18 on:** January 16, 2016, 10:38:59 AM »

There are plenty of them on eBay - http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p5468.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=TA8435HQ&_sacat=0

raynerd · « **Reply #19 on:** January 18, 2016, 07:17:50 AM »

A little confused with this PSU.

I've taken a picture of the label and attached it. (One with light shining and glare is 10v )

I'm reading 29.8v across the capacitor which doesn't match any of the stated voltages?

Bluechip · « **Reply #20 on:** January 18, 2016, 07:56:38 AM »

Why should it ?????

They are full-load RMS AC voltages.

If you connect Sek2 from bl-bl @ 20.9VAC I would expect that to FW rectify to 29.8 VDC ish with a capacitor.

Multiply by SQRT 2 ie. 1.414 ...

If that is what you are doing ... not enough info really.

Dave

philf · « **Reply #21 on:** January 18, 2016, 08:00:31 AM »

Hi Chris,

The important winding is the 20.91v at 6a. If you rectify that with a bridge and put a big capacitor in you should get something like 30v which is better than 24v but 36v would be better still.

It would be OK for starters but if you want speed you may struggle. Also, if you've got three 4.2a stepper motors there may not be enough current if all three motors drive at the same time.

Phil.

raynerd · « **Reply #22 on:** January 18, 2016, 02:32:55 PM »

Thank you, makes sense now,

raynerd · « **Reply #23 on:** January 20, 2016, 07:05:08 PM »

Can anyone give me a little advice on home switches and limit switches.

My machine has 6 limits, 2 on each axis. I understand that to save inputs, most people wire them all in series. Obviously. You can't see that way which one has been triggered but inspecting the machine will make it obvious. What I then don't understand is why if you have limit switches, why home switches would be needed. Surely if you track back to your limits you could then move to a software "home" just like you can have soft limits. Also, a lot of people seem to home to the centre of the bed. Won't the limit switches keep getting triggered during general milling - they may be ignored by the software but it is this ok on the hardware side?

I'm obviously missing something... Help appreciated.

awemawson · « **Reply #24 on:** January 21, 2016, 02:15:24 AM »

Limit switches should be just that : an absolute limit to travel in that axis direction to save the mechanics and electronics if something goes wrong.

Home switches perform a totally different function : they give the software a reference point as to where the machine is for setting up purposes

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Author Topic: Isel CPM3020 cnc machine - electronics rebuild (Read 22863 times)