Duet3D 1HCL - Closed Loop Controller Beta test

dc42

@gruna-studio the encoders we have had most success with are the 1000 PPR (4000 CPR) ones built-into some 1.8deg stepper motors. There are some examples at https://www.omc-stepperonline.com/closed-loop-stepper-motor/.

A Former User

@dc42

OK... nice to know. Can´t wait to install it.

My X-axis works with an double shaft nema 17 who has belts on both ends. So I can´t ( at the moment) install the a new motor. How about the encoder of stepper online. I guess they´re quiet similar to the build in encoder.. or am I completly wrong?
May it´s a cheaper solution to upgrade specific axis.

https://www.omc-stepperonline.com/encoder/

This encoder would fit nicely in my system but I`m not sure if this is working in the same way as the built in encoder of stepper online nemas.

cheers Richard

https://www.omc-stepperonline.com/download/HKT30-32.pdf

alankilian

@gruna-studio Can you find some place that verifies you can get a 4,000 counts-per-revolution encoder? I looked at their web page and data sheet and I don't get a solid feeling that's true, but it might be true.

I see CPR and LinesPerRev/PulsesPerRev (LPR/PPR) used incorrectly all the time.

If you can only get a 1000 CPR encoder that's going to be too low a resolution to get you good performance. If the data sheet says CPR but they really mean LPR than it's OK, but without buying and testing one you won't know.

A Former User

@alankilian https://www.rls.si/eng/products/rotary-magnetic-encoders

But I´m no really sure with the configurations there.
Share it if you do one if you want.

I think they have all we need in future.

Concerning the stepper online encoder. I think I´ll ask them and let you know.

Cheers
Richard

dc42

@alankilian a 1000 PPR (pulses-per-rev) quadrature encoder provides 4000 CPR (counts per rev, better called transitions per rev). The EXP1HCL board uses all 4000 transitions. The 4 transitions that occur in the time of 1 pulse probably won't be as evenly spaced as the pulses, but using them still provides a benefit over using just the pulse count.

@gruna-studio if the encoder spec is 1000 PPR (not 1000 CPR) then the resolution should be OK. We've only tried one system using a separate encoder (not from stepperonline) and we've had poor results; but that may be caused by something else on that machine. If you do use a separate encoder, you need to make sure there is no added backlash in the encoder caused by it being separate from the motor. So the mounting of the encoder on the shaft and the encoder body on the motor need to be rigid. As long as the EXP1HCL is in beta test and not a fully released product, we'd rather you use stepper motors with integrated encoders, so that we can be fairly sure that any issues you report are not caused by poor coupling of the motor to the encoder.

A Former User

This post is deleted!

A Former User

@dc42
I just got my boards! thanks a lot to providing me in this early stage.
I saw there are some changes to the version 0.3. Is there already a wiring diagramm?
cheers
Richard

dc42

@gruna-studio latest EXP1HCL documentation is at https://docs.duet3d.com/en/Duet3D_hardware/Duet_3_family/Duet_3_Expansion_1HCL.

Alex.cr

@dc42 @T3P3Tony

Any idea when 1HCL will be available to US resellers?

T3P3Tony

@alex-cr we have orders in from at least Filastruder (need to check with the other ones). I hope we will start shipping reseller orders to them next week.

Alex.cr

@t3p3tony

Much appreciated!

cloudseeds

@t3p3tony Anything for Germany/Europe? I am currently testing 1XD with SERVO42C but that makes little sense if 1HCL is available soon.

madmattco

Apologies if this was addressed before but I was wondering why the choice of using the 5160 and it's built-in encoder input was not used?

T3P3Tony

@cloudseeds we have dispatched some to Compass-DHM and Dold Mechatronic , I hope both of them will list them soon.

dc42

@madmattco the EXP1HCL uses the TMC2160A because it supports the direct coil current control that we need for closed loop node. The TMC2160A does not support an encoder. In any case, reading the encoder using the built-in encoder support in the MCU is faster than reading from the stepper driver over SPI.

martin7404

I have a question can I use mini with 1HCL board ?

T3P3Tony

@martin7404 yes you can use it with any of the Duet 3 Mainboards (6HC, 6XD and Mini 5+)

CNCModeller

Hi @t3p3tony,
Are there any 1HCL units on the way to UK resellers? I've checked E3D and Oozenest and nothing is showing there at the moment.

Many thanks
Barry M

dc42

Any one using EXP1HCL boards with firmware 3.4.0RC1, please upgrade the EXP1HCL firmware to 3.4.0RC1+2 available at https://www.dropbox.com/sh/2dt7sbqpx6l74np/AADn4-lpcil1iqnWKkiVri3Ia?dl=0.

tristanryerparke

Has there been any progress on simultaneous tuning of two motors driven by individual 1HCL? I’m looking to control a dual motor Y axis gantry with auto squaring.
Thanks