NM200 S2 spindle motor and drive

[newton009]

Does the NM200 S2 spindle motor and drive suffer the same problems? Suggested by Zone member JoeBean... motor and drive are the same.

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http://www.cnczone.com/forums/bencht...dle_mach3.html

[JoeBean]

You mean the low end torque issues/stalling?
The motor & controller on the s2 is from the same company that is selling to Keling. I can't get a decent pic of Keling's controller but I'm guessing it's the same. The problem people are having seems to be intermittant. Personally I have stalled the motor twice but it was under extreme conditions. So I haven't personally had these problems.

But, at the same time, I almost never have to be running at the extreme low end speed-wise, where the problem usually seems to pop up. I also got an early version, so the problems may have been created with later revisions of hw or sw.

In theory, if the current NM-200's are still using the same spindle setup then they could be affected by the same problem.

[cteufert]

I have done some checking about the motors and drivers used in the Novakon mills. The NM-200 uses a 2200w motor and driver. The NM-145 uses a 1100w motor and driver. Based on the photos I got by email the 1100w driver used in the NM-145 is the same one that is having the issues as discussed in the other thread. Sangmutan in China is the manufacturer.

I sent a message to keling.net who resell the motors / drivers, asking if they had received revised drivers from Sangmutan yet as promised by Zhang of Sangmutan. As of earlier this week they had not. I would be surprised if any of the NM-145s have a different driver since it and the drivers were announced at nearly the same time. Hopefully since Zhang promised that an engineer was already working on the problem at the end of December it may already be resolved but the drivers have not reached the US yet due to the 4-6 week transit time by ship.

If the correction has been made it would have been available to How-Mau very quickly so HM-145s and NM-145s being manufactured now may have a different driver and could also be in transit to the US. This is totally my speculation based on the assumption the problem has been resolved.

I am very familiar with PIC processor based BLDC motor controls and in fact attended a 3 day conference / training program in Phoenix last year where I took 3 classes in motor control. The issues mentioned in the other thread perfectly describe a BLDC motor that is being driven open loop or with a very poorly tuned closed loop. One of the labs I participated in included running a BLDC motor open loop. It was noisy, stuttered and had little low end torque. It also had difficulty changing speeds or adapting to changing loads. Applying a sensorless closed control using the same motor and electronics made an impressive difference in all areas. It also allowed a much higher top speed. The motor ran cooler since it was not working against itself when the timing was off. What is most impressive is sensorless control has lower performance at low speed than control that uses sensors like the hall effect sensors built in to the Sangmutan motor.

Based on what I have read the 2200w motor and driver are working better so most likely the driver is better tuned than the one used to control the 1100w motor.

Does the NM200 S2 spindle motor and drive suffer the same problems? Suggested by Zone member JoeBean... motor and drive are the same.

Follow this post:

http://www.cnczone.com/forums/bencht...dle_mach3.html

[cteufert]

Reading in another forum it appears that Sangmutan has corrected the motor / driver board issue. No word yet on how to tell a good motor / driver from a bad motor / driver. Sangmutan says several manufacturers have tested down to 400 RPM and were unable to stop the motor by hand.

Charlie.

[rodsprit]

Interesting read, cteufert.
Why isn't the hall effect sensor in the sangmutan motor being used? Why not run it closed loop, is it much more expensive to produce a driver capable of doing that?