BLDC and fanuc redcap parameter problems?

I am attempting some bench testing before a VMC retrofit. I have a fanuc 5S motor, AMC BE25a20AC drive, mesa 7i77 and a parport breakout board for the tests. I realize other mesa boards will be needed for the actual retrofit, this is just to prove the redcap can operate under linuxcnc using the BLDC component. Running 2.7 master under debian wheezy.

My test setup : Drive in velocity mode, running open loop velocity mode with no positioning loop yet. Using onboard pot for speed control.
Drive has red/green led which indicates fault as well as valid commutation signals.
Using encoder feedback to drive for velocity loop.
Fanuc 4 bit graycode and the 3 hall outputs are all ran through the parallel breakout board.
Encoder fed through 7i77 and displays properly.

BLDC setup
loaded with cfg= fHT
no other parameters loaded or modified from defaults I found the pattern set to type 19 by default which does give a green led on the AMC drive. BLDC is being used for comm code conversion only, fanuc gray 4 bit to 3 industry std hall signals.
There is that youtube video of a fellow doing the exact same bench test and he claims to have used pattern 9 or 36, those patterns show as non valid on the amc drive. I tried all 48 patterns and none gave smooth running. Some patterns ran others didn't but none ran smooth. Tests were limited to a couple hundred rpm max.

Any suggestions on getting the motor running smoothly? Trying all motor power combinations along with all 48 comm patterns is obviously not a option. I appear to have good signal quality, bldc is code converting. I must need other parameters set or something. Knowing which BLDC pattern I should try would help a lot.

Thanks!
George

I did run through all 48 combo's using the halcmd window in "show hal configuration", without restarting. I did not try the motor UVW combinations for each pattern.

I was not aware that the fanuc 4 bit conversion was not a perfect fit, hopefully results better than I have now are possible. I have the fanuc encoder hooked up and feeding into the 7i77 giving me a axis dro, so the encoder is there and that method is possible if just code converting does not work well.

Do I need to set any other parameters for just code conversion? Like the number of poles?

I guess I am off to try a whole lot of BLDC patterns and motor wire combinations, not looking forward to that one !

Another question,

The guy on youtube said he had used both pattern 9 and 36, both which worked well just with opposite rotation.

Have the BLDC patterns and their numbers changed over the different development versions of BLDC or have they remained the same all along?

If the same, I will start off using pattern 9 and 36 and experiment with motor combinations for those patterns first.

Well, I lost another round in the battle.

The AMC BE25a20AC drive has a red/green status led. That led goes red if there is not a valid commutation pattern. AMC shows in a video rotating the shaft with the power leads disconnected and verifying the led remains green. I did this test for all 48 BLDC patterns and about 12 of them gave a steady green led while rotating the motor shaft.

Next, I tried all 6 motor power lead combinations for each of the 12 BLDC patterns that gave a solid green led. None of the combinations gave a decent running motor. The best I got was quite rough.

I am assuming for the fanuc 5S that 120 deg comm is the correct setting on the AMC drive, not 60. Not a lot of info of that sort around on fanuc motors.

As for using the encoder for commutation, I have read all that I could find on the process but the BLDC docs do not detail the process much, only the pins/parameters.

How the youtube guy got that motor running with patterns 9 and 36 I have no idea. He used the same drive that I have but did not provide much details. Patterns 9 and 36 give a red led on the drive when I tried them. With a red led, the drive is in a fault mode and cannot be ran.

Andy
I have a number of motors here that I would like to use but I dont have drives for them. Would it be possible give some sort of schematic on how to use this component with discrete bridges or drives.
I am trying to follow what is being discussed here but have very little insight as I dont understand how things are strung together

andypugh wrote:

gmouer wrote:

I am assuming for the fanuc 5S that 120 deg comm is the correct setting on the AMC drive, not 60.

I would have assumed 60, actually.

How the youtube guy got that motor running with patterns 9 and 36 I have no idea. He used the same drive that I have but did not provide much details.

You could ask him, I found him quite communicative.

I will try and contact him through the youtube video, that is the only way I know unless you have contact info. As far as I found in searching he is the only one that has come close to getting a redcap running using BLDC. He didn't have a positioning loop and did not understand why the motor had no holding torque but that is a easy task once the motor is running well in open loop velocity mode.

I am going to give it another try today, setting the AMC drive switch for 60 deg commutation. The other non fanuc brushless motors I have used were all 120 deg so I just assumed........ Maybe a bad assumption with luck. Again, I will report back..