Need Advice on EMC2 & Control Boards

[billbells]

Hi CNC Community - Great Forum - I'm new to posting here & newish to CNC (so please treat me gently !!)



I have acquired a Defiance CNC machine as a project, which is in great mechanical condition, but the control side is not working. The machine was probably one of the last before Defiance went under, and I understand it has never run for long without issues and has always been unstable (hence the condition).

I've managed to get all almost everything - spindle and tables to work, it just will not get past the initial toolchange homing sequence no matter how hard I try. All the sensors on the changer mechanism are working and trace back to the board OK, so my ignorant guess is that the PMAC program is a bit messed up, and I really do not want to try to understand the Delta Tau PMAC, it looks way too complicated for my brain capacity.

Anyway, as a project, and a steep learning curve, I intend to enjoy the coming winter months in an attempt to run it under EMC2 from a PC and retire the old on-board computer, DOS based Evolution software and PMAC, but keep everything as is from the opto board outwards.

The servos and controllers are all yaskawa, the spindle invertor is Saftronics. The encoders are on the leadscrews. There are a load more I/O connections, but they are all fairly logically put together and understandable.

SO, sorry for the preamble, but the real question is what is the best interface board between the PC and the machine with EMC2 for me to play with ?

Has anyone got any similar retrofit experience, or bad or good experience or recommendations on matching motion control boards with EMC2 for servos ?

Cheers Bill

[f32cpe]

I would join the emc2 mailing list.
https://lists.sourceforge.net/lists/listinfo/emc-users
They have some very helpful people there. Some of them are involved in the development of electronics to interface.
I have found them to be very helpful.

Mike

[DonnieET]

If your servo are +/- 10 volt then you will need something like the Mesa 5I20 with the 7I33 Servo interface card.

WWW.mesanet.com

[billbells]

RE Sourceforge

Thanks Mike - I have subscribed to that forum and will post the same question.

[billbells]

[QUOTE=DonnieET;644308]If your servo are +/- 10 volt then you will need something like the Mesa 5I20 with the 7I33 Servo interface card.

Thanks DonnieET

I checked the specs of the servo controllers - it gives +-10v for the reference voltages for the speed and torque.

Is that what your +/- refers to ?

[chester88]

yes that is what he meant. What type of opto boards does it use? If its OPTO 22, 24 position relay boards with 50 pin connectors then they would work well with the Mesa products. Hw many I /O pins do you need?

[billbells]

The opto board is Delta Tau ACC-34AA which has 32 i/o lines

looking at the wired unit, it is currently using 17 lines

[Ron22]

Personaly I would get the Delta Tau working. But then I know Delta Tau and do not know EMC2

Answer to you question. 99% chance you Servo drives are +/-10V input either torque or velocity mode. There is Encoder feed back into the PMAC card. Depending on the drives it might go through them or not. Usaly the PMAC does all of the tuning of motors and the servo drive is just an amplifer.

The Acc34AA is prproprietary Delta Tau board. It is just an I/O board that talks to the PMAC card. Take it off and put on Ebay with rest of the PMAC parts. You need to replace this with some other I/O. I would replace it with Opto22 I/O.

Some questions
What modle Yaskawa drives & motors? You should be able to look up all the spec's. Is there an encoder on the motor and one on the leadscrew?

[billbells]

The motors are Yaskawa SGMP 04u314 spt - sorry, I should have said encoders are in motors.
Drives are SGDA 04 AS
Spimdle Drive is Saftronics VG5

[jmelson]

Originally Posted by billbells The motors are Yaskawa SGMP 04u314 spt - sorry, I should have said encoders are in motors. Drives are SGDA 04 AS Spimdle Drive is Saftronics VG5

The AS means these are "speed" drives, or what we call a velocity servo. It can take +/- 10 V analog velocity commands, or step pulses. It requires a program you can download from Yaskawa to reprogram the drive. You also have to make up a special cable to connect the programming port on the drive to a PC.

You really have to keep the drives, the SGMP motors use a proprietary commutation scheme encoded into the encoder's index track. The drives produce a decoded ABZ signal that you can feed to your servo interface.

Jon