STEP-BY-STEP: Installation of SilentStepStick-Drivers on UMO

[mariuszem 4]

4 minutes ago, JohnInOttawa said:

 I will change X, Y and hopefully Z but will leave the extruder alone for now.

Leave it. TMC for Z is useless. Really, let it go with allegro.

[JohnInOttawa 104]

I know this is a very old topic - but I finally got around to installing these on my UMO (no heated bed).  I think I have followed the instructions on this thread, and things are indeed quieter.

 

Because I had the time, I installed all 4 of them.  X and Y are certainly quieter but with all sorts of layer shift starting at about layer 3, Z is quieter but for some reason Z no longer homes correctly and the extruder is underextruding and eventually not extruding at all.

 

I tried with the Vref all the way down at 0.8, got the layer shifting right there, and have been increasing it slowly, really not seeing any improvement, now at 1.1.  I assume I am shortly (if not already), going to experience overvoltage heat issues.  I also note that the shift follows a rapid move and Trinamic has a video recommending reduced acceleration rates.  Could this be a fix and, if so, how far do I need to cut back on acceleration from default settings?

 

The extruder is a whole other thing.  The retractions sound awful and then eventually stop.  I am reducing voltage, will continue to do so, but the next step will be to revert back to the old driver.  The noise was not that great to begin with and it's that I am targetting.

 

Z axis - the previous owner may have changed the lead screw (unable to verify), so I am wondering if my steps are wrong.  In any event, the previous driver and steps at 533.3 homed correctly.  Now, with 1066.6, homing causes the build plate to rise, hit the limit, back off, then rise and hit the limit again.  I would have thought that homing would have an offset from the point the limit is reached, so I am wondering if there is a discrepancy between where the machine thinks that bed is and where it is in reality.

 

I guess I may be into a process to measure the correct steps/mm  on Z.

 

As my primary is a UM3 and is happily ticking along, getting the UMO back is more of a wish than a need.  These are authentic chips bought from a reputable source, so I am pretty sure it's something I'm doing wrong.

 

Any and all advice gratefully accepted. 

 

Thanks!

John

[maartenw 6]

Hi John, in march 2016 I replaced the drivers for the X and Y-axis only, and got (and still have) a nice and quite UMO. So what you could do is set back the driver for the Z-axis (it doesn't make a lot of noise) and for the extruder.

Recently I replaced the extruder for a Bondtech one and finally got a reliable feed without underextrusion.

It's been a long time ago, but I do not recall the steps/mm had to be changed. Maybe I am wrong, but I would suggest to double check on that.

[JohnInOttawa 104]

Thank you!  I have been wondering about doing that configuration.  Nice to have your feedback that it would work OK.

 

I have been doing some searching and suspect that, despite my beliefs to the contrary, I may have the infamous 'White V1.3' Fysetc units.  If so, then I have some soldering and a retest to do tomorrow. 

 

Your addition of a bondtec to the UMO sounds interesting.  Which Bondtec model did you go with?  I did not know this could be done on the UMO.  Defintely something I would look into.

 

Thanks again!

John

[maartenw 6]

Hi John, I came accross the Bondtech extruder when I had extreme and irregular underextrusion problems. I searched the forum and looked at the Zero gravity design. For this design, several items have to be 3D printed which should have thermal and structural stability. Impossible to make with a printer having underextrusion problems...

The link to this design is:

In this post also the Bondtech extruder is mentioned.

Looking further for this Bondtech, I found this post made by Ataraxis:

I just followed this post.

Now the mentioned Bondtech extruder is sold as a UM2 upgrade, but it is what Ataraxis described and functions excellently om my UMO. Indeed the delivered wires are a bit short, but useable. Be aware the Steps/mm for the extruder has to be adjusted - I made an adjustment in the start-GCODE in CURA to make sure this value is used on the UMO (and in your case on the UMO only).

 

I asked a confirmative question to Bondtech about which specific Bondtech to order. This question was answered really quickly and friendly.

Btw: I also exchanged the bowden for a PTFE tube, also supplied by Bondtech.

Good luck!

[JohnInOttawa 104]

Excellent!  Thanks.  I'll check that out.

 

My issue was indeed an open solder connection due to the V1.3 mod.  This was the video that helped me out, in case someone else hits this issue.  I have not put my voltages as high as recommended, yet, so far things seem to be tracking OK.