My UM2 (with Flex3Drive) print quality wasnt what it used to be.

My UM2 (with Flex3Drive) print quality wasnt what it used to be. Got tired of endless investigations and replacement parts (belts, bearings, nozzle, driveshaft etc) to fix it, all made very little difference. Was sure it used to print better. Reference print on the left.

Decided to fit TMC drivers to it as a last resort. Remapped some pins onto external carrier board. Result is on the right. Fixed at last! Given the difference I might have had a board based driver or component issue (but same on both my UM2 machines??), hard to tell, but I can now safely say it has never printed this well. Super smooth !

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Tmc 2100?

@Mike_Meyer2 Yup 2100’s. Some 2130’s and 2208’s on the way for testing so will see how they go, but the now well trodden 2100’s give great results.

Which breakout board do you use for the external steppers?

@Johan_Jakobsson these are off board driver carriers from reprapworld. I have also rdered a 2.1.5 ultimaker controler board from china, its a clone board except it has sockets instead of surface mount driver chips. Will be fitting it out with TMC drivers. I think this is the least hassle approach. The above was more using dev parts to assess

The 498x drivers in UMs can ripple just like 8825s when the motor inductance is too low for the supply voltage, (although not as bad). The slower you print, the more likely you are to see driver ripple flaws. Although that’s pretty “wavy” more than “ripply” (heh) so it might’ve been something else.

@Ryan_Carlyle Yup totaly agree, something was getting continually worse. The degree of troubleshooting has been all covering (including the ROSC mod and smoothers). I have hacked the machine about quite a bit in the past, so may have disturbed/damaged something at component level. That being said, this just took my UM2 to a whole new level it has never been before.