SpiderBot Delta 3D Printer

Silent StepStick

posted in Customisations
Thursday, June 04 2015, 10:23 PM
I am exchanging my drivers for the new SilentStepStick. A new driver chip will make the steppers less noisy. I've sen them used on an Ultimaker so all you hear is the swish of arms moving.

The SilentStepStick is NOT a drop in replacement, some fixes need to be applied.

I have bought 12 (5 for the spider bot a few spares and another project or two) and already "ruined" one. When soldering in the pins, they go in "upside down". The cooling is thus done on the downside of the board, so place the heatsink on the pcb not the chip.

I've tested the 2nd on with my Easy Stepper tool.

My progress is slightly delayed as I burned out my Megatronics board. :( Fumbled with the wiring. It appears I only(?) burned the 2560 Atmel processor (it has gotten a "bump" as the chip inside exploded) and a good friend had the skills to solder on a new one. Current plan is that sometime in the next week I will run the printer and if all is well, I will attempt driver replacement again. And then I will update this thread with the exact fixes.
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    Responses (5)
    • Accepted Answer

      Monday, June 08 2015, 06:53 PM - #permalink
      Minor update: Well, spiderbot operational again, after the 2560 chip replacement. Driver replacement next week.
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    • Accepted Answer

      smile
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      Sunday, July 12 2015, 08:05 PM - #permalink
      Did you made it to work?
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    • Accepted Answer

      Monday, July 13 2015, 06:21 PM - #permalink
      Real Life and Summer holiday got in the way. ;-) I'll update when I do get it done.
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    • Accepted Answer

      Sunday, February 07 2016, 06:28 PM - #permalink
      My, my ... time does indeed fly. So I finally got down to installing the SilentStepSticks. (And new thermal probes at the dual head, and a better powersupply for the RaspberryPi/Octoprint)

      At this time of writing I have partial success. No smoke, and the home code works. The motion is silky smooth and much less noisy. Almost silent when moving slowly. :D I have only done the motion, I'll do the extruders afterwards.

      When it is working I'll give all the secrets. Beware - it is not just plug-n-play.

      But the absolute positions are all wrong - Z=100 is at the bottom "Oh, well, probably twice the steps/mm", I thought, easy enough to fix in the firmware.

      But here someting is not quiteright. Changes in the firmware value ZAXIS_STEPS_PER_MM (it is the value used for all towers) seemed to have no effect. Seems it retrieves te value from EEprom. So I tried adjusting that. CRUNCH :( -the machine went besserk the moment the value was changed. Killed power, and on next powerup all was well. and the value had been stored. (This happens with both ReptierHost and doing the M206 command manully in Octoprint). When doubling the ZAXIS_STEPS_PER_MM it made matters worse (?! like it was the inverse, mm-per-step). When halving it the firmware felt all Z moves where illegal/out-of-bounds.
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    • Accepted Answer

      Monday, March 21 2016, 07:35 PM - #permalink
      After a bout of intens work (the kind that keeps me from playing with my Spiderbot), I had time to look at this again.

      It works. I do not know what went wrong with the step/mm changes last time. This time I simply used the parameter setting in reptierHost and/or using the M206 command directly (CAREFULL M206 T3 P11 X88.89 )

      (The other changes with replacing thermocouples went well, but the upgrade to the latest octoprint has a small glitch - another thread, another time)

      Summary : The silent stepstick only give half the resolution of the drivers my Spiderbot was shipped with which use DRV8825. I have only verified it prints again, not run any complicated prints.

      Hardware change is simple enough - Remove the old stepsticks. Remove the 3 jumpers underneath the driver prints. Solder a small wire from the GND pin to CFG1 on the SilentStepstick. (Adjusting the max current is harder)
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