Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
Finally looking at replacing the Linux based Servo3IO and CPU10 DC servo drive in my Ajax DM45NC mill with something like the Acorn. I looked at other controls but am pretty comfortable with the Centroid software so why learn something new? I'm hoping to get as much pre-wired as I can before cleaning out the cabinet. The power connections for the servos are obvious and I plan on keeping the existing servo power supply. I have three of the 150 volt, 20 amp Machdrive BRC drivers coming to drive the existing servos. I have not ordered the Acorn board yet - still making sure this is the route I want to go. I need to figure out the brake on the Z axis and I'd like to make a panel that the three 9 pin sub d cables simply plug into instead of cutting them off and rewiring them to the DC Servo drivers. Does anyone happen to have the pinout of the 9 pin encoder cables that plug into the bracket connected to the CPU10 board in the PC?
Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
Ask Centroid support about upgrade options. There are ways to either keep the SERVO3IO or go to ALLIN1DC. Both will be simpler and better than trying to piece together something with ACORN.
Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
The ALLIN1DC would definitely be a nicer solution. It has the same mounting footprint as the SERVO3IO, and would allow you to use the existing servo power supply, and to use the existing motors and encoders without changing the cables.
The pin-out for the 9-pin encoder plugs is found on nearly every Centroid DC-servo system schematic. It is:
pin 1 : n/c
pin 2 : COM (0VDC)
pin 3 : /Z
pin 4 : /A
pin 5 : /B
pin 6 : Z
pin 7 : A
pin 8 : B
pin 9 : Vcc (+5VDC)
With these assignments, encoder channel B leads A in positive rotation, which is CW as viewed from behind the motor (or CCW if looking at the motor shaft).
Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
Thanks for the information - that will help a lot.
Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
Quote:
Originally Posted by
cncsnw
With these assignments, encoder channel B leads A in positive rotation, which is CW as viewed from behind the motor (or CCW if looking at the motor shaft).
In less technical terms, A and B signals are swapped verses "industry standard". This is a likely point of confusion if you wire to different drives.
Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
Thanks for pointing that out - I had not looked that closely at it yet. Still gathering information at this point. I did sent a message to Centroid but no reply yet (beyond the one from cncsnw). I've even looked at a couple used DC3IO setups on ebay but have a feeling I'd be buying someone else's problem and not really bettering myself - Intermittent problems are a bear to troubleshoot - just wish I could say I need to replace "A B or C" and be done with it, to be honest. The best I can do is say that it is either the CPU10 or the Servo3IO at this point, or possibly even a software glitch. I can't imagine the motherboard causing the issue (I replaced it once already anyway). I am looking to try a SSD in place of the compact flash, if I can ever figure out how to clone the Linux software over to the SSD and see if it will boot in my motherboard.
Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
Quote:
Originally Posted by
SEK22Hornet
Thanks for pointing that out - I had not looked that closely at it yet. Still gathering information at this point. I did sent a message to Centroid but no reply yet (beyond the one from cncsnw). I've even looked at a couple used DC3IO setups on ebay but have a feeling I'd be buying someone else's problem and not really bettering myself - Intermittent problems are a bear to troubleshoot - just wish I could say I need to replace "A B or C" and be done with it, to be honest. The best I can do is say that it is either the CPU10 or the Servo3IO at this point, or possibly even a software glitch. I can't imagine the motherboard causing the issue (I replaced it once already anyway). I am looking to try a SSD in place of the compact flash, if I can ever figure out how to clone the Linux software over to the SSD and see if it will boot in my motherboard.
I just upgraded a CPU10 to the latest (and last) software revision for it I ordered the SSD from Centroid, preloaded and configured. You just need to send them a report.
I also upgraded the motherboard to one of their recommended motherboards. I spent about $100 buying it off of ebay with 2gig of memory. Machine is working very well and was the most cost effective solution.
I agree with Marc (CNCSNW) if you want to upgrade, go with the All in One DC. It would be the easiest path and less downtime. You will retain the true closed loop system.
I think CPU10 with the latest software revision is a good inexpensive option too. All in about $500 if you order the new SSD from Centroid preconfigured and you track down a motherboard.
All in one DC is going to set you back $2250, you will need a new PC about another $200-$500 and you don't mention if you have a pendant/console with your current control. All that is going to add up.
You should post a picture of your machine, and a shot of the control cabinet.
I will tell you the biggest issue I had was USB compatibility. Once I upgraded the software, all that got much better.
Pictures of the mill and the M400 control: https://photos.app.goo.gl/JYQVB3aBjC7xWX3Y8
Marty
Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
I upgraded the motherboard and went to the latest software revision a couple years ago. Only difference is that I kept the Compact Flash card. I did manage to clone the compact flash card to a Samsung 16 GB SSD that I had and tried it last weekend - didn't have time to run any parts but it booted up fine and went through homing fine. I dry ran a couple small programs and they ran fine, so I'm no worse off than I was before. It boots pretty fast - not sure how much ram I have - either 1 or 2 gig and I do recall the board is an AMD running a Sempron chip. I think it is a socket 754 but not sure - I'd have to open it up to look. I added a couple USB extensions that mounted in the side wall of the cabinet so now I have 3 working USB ports (part of my original upgrade). The only other thing I've had to do was replace the VFD which died abruptly about 6 months ago. All in all I have about $1K in this machine. Makes it really hard to spend the $2250 for the allin1 upgrade. Yes this does have the pendant - it is a little rough - the cycle start button is very well worn. I'll take a few pics of my machine and post them.
Dan
Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
Last weekend I had some parts that I needed to run - the mill did it's usual stunt - start the program and anywhere from a minute or two into the run the spindle would just shut off - hit the feed hold or tool check and and resume the program and all was well for a few minutes, then it would do it again. Fought with this for a couple hours and gave up. I went ahead and picked up an Acorn board and 3 MachDrive BRC step and direction brush type DC motor drives. these are rated at 150 VDC at 20 amps. Still had parts to run this weekend, so I went back and tried the mill again - it stopped once then let me run the parts with no problem after that. So I tired to figure out what the difference was. Last weekend, the shop floor was soaking wet with humidity. this weekend it was pretty much dry. - hmm made me wonder. My shop is not temp controlled (obviously) and last weekend the humidity was literally dripping off the machine. This weekend, just the floor of the shop was wet. I put small light bulb in the control cabinet Saturday - Ran the machine Sunday with no problems at all. I think my intermittent problems with this machine are probably related to the environment! Time will tell, but I may not need to replace the controller after all.
Re: Centroid CPU10 encoder connections - Replacing Servo3IO with Acorn
Actually, I have not had any more trouble with the controller since putting the lamp in the cabinet - I also added fan in the shop that runs all the time to keep the air moving - so far so good - the shop is drier and the machine i behaving itself. The Acorn board is now going to be used in a G0704 cnc conversion -
