Need Help!- Amps to Motors interface

[Ben Colby]

I am having CamSoft installed on my Brother TC-221 Mill/Drill. The technician
I hired to do the job has hit a snag. He insisted on installing new amplifiers
on X,Y and Z and a new drive on the spindle and I reluctantly allowed it.

We now have a situation where the drives will not communicate with the Sanyo motors that are on the machine. The drives are from Automation Direct and are 400w on X&Y, 750w on Z, and 3000W on the spindle. The original Sanyo motors had (have) tach generators on them that the Camsoft manual says to disconnect. We tried a line drive encoder from Automation Direct that matched the Amp but still got nothing but the same alarm.

I do not want to replace my Sanyo motors because they are in very good shape,and the project is running over budget and way over in terms of time. Does anyone know of any non-proprietary servo amps and spindle drive that will interface with the AC Sanyo motors.

thanks in advance,
Ben
COBRO MFG.

[Al_The_Man]

It is extremely rare to see tach's on AC servo motors?
Are you sure they were tach's and not resolvers?
What kind of commutation is used on the Sanyo motors?
Al.

[ampedup]

Originally Posted by Al_The_Man It is extremely rare to see tach's on AC servo motors? Are you sure they were tach's and not resolvers? What kind of commutation is used on the Sanyo motors? Al.

I am not really sure if they were tach's, resolvers or part of the commutation. One part of the electrical schematic list the encoders as TG's. The drawing for the motor/encoder plug lists wiring the plug with the normal encoder wires and another group called CS which runs at 15 VDC and contains wires CSA, 15G, CSB, 15G, CSC, 15G, a total of 15 wires in the plug. As far as the commutation goes, there is nothing in the documentation that tells about that. Can you tell from the information I have given you?

CamSoft requires torque control mode and a +/- 0 to 10 VDC signal to drive the servos. The mode is not settable on the old Brother amps and I could not find a 0 to 10 VDC signal input.

We are looking for inexpensive servo drives that will work for these motors. The commutation seems to be the issue.I talked with a tech from one of the servo manufactures and he indicated that they have a digital drive that will provide commutation through the drive itself but they are a bit pricey and they are much more drive than we need.

I have not finished my research but any information you can provide would be helpful.

Thanks, Al

[Al_The_Man]

If the CSA/B/C are the three commutation channels you should be able to use AMC BLDC amps, Although if they are fed with 15v there is a possibility they are actual Hall effect sensors, these are the older method of commutation, nowadays the three tracks are on the encoder disk to simulate the hall effect devices.
Do you know what method the Brother amps had for command signal if it was not 0-10v analogue?
Al.

[ampedup]

Originally Posted by Al_The_Man If the CSA/B/C are the three commutation channels you should be able to use AMC BLDC amps, Although if they are fed with 15v there is a possibility they are actual Hall effect sensors, these are the older method of commutation, nowadays the three tracks are on the encoder disk to simulate the hall effect devices. Do you know what method the Brother amps had for command signal if it was not 0-10v analogue? Al.

I am going to have to study this more. My knowledge of hall effect sensors is limited.

I did chat with the AMC tech for quite a while today. He is the one that recommended the digital drives. I browsed the AMC web site and noticed that most of the AMC encoder/commutation is driven by 5 VDC. This still leaves me out in the cold but I have only scratched the surface with respect to the commutation issue.

It really would have been simple to use the OEM drives if I could have answered your question myself. There are 3 drives mounted in one unit. Each drive has several circuit boards that input from different places like the encoders, main board and slave boards. I could not find any indication of the command signal anywhere on the 46 pages of schematics. They very well could be driven by 0 to 10 volt signal. I just couldn't find it.

Thanks for the help so far. It does get the juices flowing and helps me to get focused. Al

[Al_The_Man]

If you go with AMC drives, these are the ones I use with Galil and which Galil actually relabel for themselves, they do not require the encoder input, just the hall effect, if you do have the descrete hall effect devices that require 15v with a couple of components it should be easy to tailor a 5v clamp circuit to interface to any 5v input.
Alternatively 5v power could be tried to see if they switch from ov to 5v output.
Al.

[ampedup]

Originally Posted by Al_The_Man If you go with AMC drives, these are the ones I use with Galil and which Galil actually relabel for themselves, they do not require the encoder input, just the hall effect, if you do have the descrete hall effect devices that require 15v with a couple of components it should be easy to tailor a 5v clamp circuit to interface to any 5v input. Alternatively 5v power could be tried to see if they switch from ov to 5v output. Al.

Do you have the model/part number of the AMC drives? I could not find the specific drive you recommended below with that designation.

I had thought about reducing the voltage of the hall effect devices but this job is complicated enough as it is, I do not have a lot of room left in the panel and I want to keep things as simple as possible so Ben can fix them, should he need to. Additionally, I would like to update the sending units to something more current so, hopefully, this will not happen again. I would probably just order encoders with commutation from encoder products. If you have another more budget conscience supplier for just the hall commutation, or encoders with hall commutation, I would be happy to know that.

After all that is said, trying them with 5 volts is a good idea and I have nothing to lose.

Does the Galil take the positioning signal from the Hall sensor? It seems like there would need to be some sort of input to the breakout box where the encoder wires would go?

Once again, I appreciate your help. Next time I am north of the border, I will buy the first 20 rounds!
Al

[Al_The_Man]

The size of the motors and the voltage would be needed to size the drives.
If you replace the encoders with hall effect tracks you need to know the pole count of the motor, there is a few previous links here on it, but if you power up the halls, and monitor one of the the outputs and count how many times the output goes from 0 to 15v and double it, that is the pole count, e.g. 3 highs is a 6 pole motor..
I would first look at integrating the present hall effect a couple of resistors and a zener diode on each output maybe all that is needed if they do not output at 5v.
The Galil uses the encoder and the drive the halls so yes you would have to direct them to the respective inputs.
Al.