UM3 TMC2208 Upgrade

[shai 1]

Hi all,

 

Just acquired a UM3 regular and looking to make some changes to it. I'm specifically interested in upgrading the drivers to TMC2208. I've only seen maybe 1-2 threads on this forum discussing that but without any guides. I'm somewhat experienced in EE and have no problem soldering QFNs or other small parts. However, there is only one shot at this, since if I connect something the wrong way, it will possibly fry the board. Has anyone here attempted to replace the allegro drivers with TMC2208? I've seen some aliexpress boards that offer TMC2208 drop in replacement for ultimakers, but I think that is for UM2 and I also don't trust aliexpress board designs. 

 

I know I can just get a newer duet or other board with TMC2208, but I'd like to preserve the Ultimaker LCD and camera functionality. I've found the schematic of UM3 here: https://github.com/Ultimaker/Ultimaker3/blob/master/PCB files/1548-I Ultimainboard/Schematics and layout pdf/Schematic Prints.PDF and here is a TMC2208 schematic for the driver: https://github.com/watterott/SilentStepStick/blob/master/hardware/SilentStepStick-TMC2208_v20.pdf

 

My understanding is that both drivers' pins are fully compatible, just some resistors/caps might need modifications. Is this correct? How would you go about setting the power to the 2208 driver? And I also read that you need to pre-program the driver before soldering it to put it in legacy mode? Is this true?

Any suggestions on how to go about this would be super helpful!

Edited April 25, 2022 by shai

[shai 1]

So, I have gone ahead and done the hard work of figuring out what needs to change. This should work. I will update this thread after I have done some testing!

 

[Yo-NuTZ 3]

Hey. Even if this post seems to be somewhat old, i love your ideea and maybe i'll try on my own. I had no idea of this compatibility but it's very good. Couple of things though: the resistors you crossed out need to be removed? Also, in the end, in what mode/setting would the tcm2208 run? I do have soldering skills but never succeeded with QFN ...

 

 

 

 

[Yo-NuTZ 3]

While trying to understand what needs to be done, i have stumbled upon a very helpfull PDF from Trinamic:

https://gzhls.at/blob/ldb/c/9/4/2/ffa39ccd8323907ea35953b5f5e3ef9dfd3c.pdf which is called How to replace Allegro A4988 with TMC2208.

 

Another thing is as far as I remember there was this one time programmable bit (succeeded a long time ago in programming / setting it) but it was mostly to set StealthChop or SpreadCycle mode. There was a youtube video on it which was very helpfull. Let me know if you want me to search for it, since i couldn't find it again on a quick google.

[Torgeir 228]

Hi @Yo-NuTZ,

 

This might be a risky modification, -however if you have skill and the right tools for replacing QFN (quad flat no pin) chips.

It's possible.

I would only change X,Y and Z (working only in legacy mode without the need of re programming).

I would also use the existing PWM (pulse width modulated) signal used to control the stepper current.

The low pass filter would need to be modified to match the TCM2208 voltage for the required (Ampere/torque).

There's one filter for both the X/Y and another for the Z.

Doing it this way, does not need any change in the firmware.

 

Here is the videos of how to use legacy mode:

https://www.youtube.com/watch?v=TubpTMFkbVs

 

And here is another video of how to program OTP (one time programing) mode and "dynamic control" mode:

https://www.youtube.com/watch?v=9V8iEEAB15g

 

Thanks

Torgeir

[shai 1]

I tried to replace it but ended up damaging my board. Not sure if I replaced it correctly. Might be worth someone with more electrical experience to do a guide.

[Yo-NuTZ 3]

@shai:

 

Good to know.

 

I talked to an older friend and he'll do it for me. Since you've said you ended up damaging the board I think I will initially start with the motor for second hotend/printhead hoping that even if I am unsuccessful at least I would still have the first one.

 

I'll try to post my findings afterwards if I am successfull. If you have any tips on what to avoid doing I'm open to them :)

 

 

Edited December 30, 2022 by Yo-NuTZ

[Yo-NuTZ 3]

On 12/27/2022 at 11:09 PM, Torgeir said:

I would also use the existing PWM (pulse width modulated) signal used to control the stepper current.

The low pass filter would need to be modified to match the TCM2208 voltage for the required (Ampere/torque).

There's one filter for both the X/Y and another for the Z.

Thank you for the tip. Could you help with a little assistance or more detailed explanation on the above?

 

I knew of those videos, they were bookmarked and prepared in my documentation phase (in which I am currently now). I already programmed the OTP bit on another TMC2208 in the past, I think I will be able to do that (switched it to spreadcycle). Honestly I am still not sure If besides legacy I should leave it in stealthChop or switch it to spreadCycle.

 

As mentioned above, the soldering will be done by someone with more skill. I will try to get additional help from him but I don't want to abuse his kindness.