Does M906 set RMS or peak current?

dc42

Thanks for your excellent work! I've added a TOFF parameter for M569 to the work list for firmware 2.01.

wilriker

@dc42 You're welcome! Was fun to experiment with that a little bit.

Having a separate parameter will definitely make the config.g file (or more precisely the M569 commands) a lot more understandable without a comment.

wilriker

For Reference

@dc42 said in Motor Whine/Loud Movement:

Could you provide chopper configuration values for various TOFF values, so that users who only need to change TOFF can try them?

Of course:

TOFF=0 -> M569 C65968 (this means motors are off!)
TOFF=1 -> M569 C65969
TOFF=2 -> M569 C65970
TOFF=3 -> M569 C65971
TOFF=4 -> M569 C65972
TOFF=5 -> M569 C65973
TOFF=6 -> M569 C65974
TOFF=7 -> M569 C65975
TOFF=8 -> M569 C65976
TOFF=9 -> M569 C65977
TOFF=10 -> M569 C65978
TOFF=11 -> M569 C65979
TOFF=12 -> M569 C65980
TOFF=13 -> M569 C65981
TOFF=14 -> M569 C65982
TOFF=15 -> M569 C65983

You'll have to add at least the Pnnn parameter to specify the motor.

I have written a small tool to create the values for the Cnnn parameter that takes into account all possible sub-values:
The source code as well as three precompiled binaries for Windows/Linux/Mac AMD64 have been uploaded to https://github.com/wilriker/chopconf-generator (binaries can be found at https://github.com/wilriker/chopconf-generator/releases).

There is also some very short usage description.

There is now a page at the wiki Reducing Stand-Still Noise.

garis

@wilriker Thanks for this - another great advantage of having a Duet. I wrote a macro for each motor with 10 seconds at each setting and voila! 2 quiet motors. But I have 4 on a core XY

I am using motors recycled from a scrapped old CTC printer. They are way out of David's recommended specs - they are 6 ohms and 9 mH. They now work quietly on X and Y with no apparent problems so even poor spec motors can work, I think. But the extruder motor went berserk (speed and direction both erratic) driving a Zesty Nimble so I quickly purchased a good 20mm pancake.

My issue is with the Z motor that as an integrated lead screw which I am hesitating on replacing. Because the 250mm leadscrew has different resonant frequencies none of the TOFF settings silenced it. Perhaps it is not possible? A fallback is to add some damping material around the Z screw near the T nut but that might be inelegant. Any suggestions?

wilriker

@garis My motors are also not optimal with 4.4 Ohm and 10mH and with my extruder motor I was not able to find a better setting than the default. That said there is no guarantee that you can find a setting that will be silent.

I do have silicone dampers on my Z steppers (which I will replace with these standard Nema 17 dampers if I not keep forgetting to order them) and also change my nut to one made from POM/Delrin which also reduced the noise or at least shifted it to a nicer frequency. You could try that.

Martin1454

So, I have been playing around a bit with it - But when I change TOFF from 72 to 69, the sound is a little bit better, but my stall detection/ sensorless homing stops working - @dc42 do you know why this happening?

dc42

@martin1454 said in Does M906 set RMS or peak current?:

So, I have been playing around a bit with it - But when I change TOFF from 72 to 69, the sound is a little bit better, but my stall detection/ sensorless homing stops working - @dc42 do you know why this happening?

I don't. Trinamic has not made the full details of load sensing public, all we know is that it measures motor back emf. I think the back emf can only be measured during the off-time; so maybe it needs a minimum off-time to work.

Have you checked whether you can get stall detection working again by changing the M915 setting?

wilriker

@martin1454 I can only say so much that stallGuard is very sensitive to any kind of changes. This means if you change TOFF you probably have to retune stallGuard. It might continue to work without adaption but there is no guarantee it will.

dc42

Please note, the TMC2660 datasheet says that the lowest TOFF setting available must not be used with the lowest TBL setting.

I have just implemented a TOFF parameter in M569. I expect to release beta firmware later today or tomorrow.

wilriker

@dc42 said in Does M906 set RMS or peak current?:

Please note, the TMC2660 datasheet says that the lowest TOFF setting available must not be used with the lowest TBL setting.

All of the values posted above have a TBL setting of 36 which is RRF default and the second highest value for this parameter at the same time.

I will add this restriction to the generator tool though.
EDIT: Done and added a new release.

I have just implemented a TOFF parameter in M569. I expect to release beta firmware later today or tomorrow.

Looking forward to this!