- version for 20mm pipes added. I have no way to test it and it may have some troubles (or may not), so print it on your own risk (and I will be glad for feedback);
- new pipe connectors added, for internal pipe diameter 16mm and 17mm (just in case you need it);
- all the files were renamed.
Belt driven Z-axis for Piper 1 3d printer. For those who don't have straight rods for z-axis (or don't want to spend much money for them).
And there is pipes connector to extend x-axis tubes to mount components properly, if you don't have longer pipes to use (but you have couple short pipe segments).
Most important question - will the axis drop down on out of power? Yes, it should. But it should move down slowly, as two motors hold it and there is pulley block to reduce load twice on the motors. And if you will tight Z rollers harder, they should hold axis in place, as In my case.
I saw only once, when axis dropped down fast - when printer got some critical error and halted during movement up. So be careful anyway.
List of materials:
x2 GT20 motor pulley
x2 GT20 idler pulley with bearing
x4 608ZZ bearing or similar
GT2 timing belts
M4 M5 M8 bolts and nuts
x2 M8 35-40mm
Short manual for upgrade. Check photos for better understanding.
- print set on part (+ pipe connectors if needed). Sorry, I used 0.8mm nozzle, so not sure about the tolerances on other nozzle size.
- put GT20 idler pulley in top mount (use M5 25mm bolt or longer). Tight nut to remove any backlashes but pulley should move freely;
-assemble top mount with M8 35-40mm bolt and nut;
-put 608 bearings and tight them with short M8 botls (I did not use nuts there, just screwed it into plastic and it hold strong enough).
Next the printer:
- remove top Z pipe corner mounts;
- remove X motor mount
- remove Z axis nuts on X rollers and Z rods;
- remove Z motor mounts
- flip X rollers to free space for the belts (or you can cut nut mounts on them to free some space);
- put new Z axis top corner mount (check the photos to see orientation)
- put new X motor mount with belt holder
- put second X belt holder, on other side. You need to have longer pipes for that on X. I took two small pieces of old pipe and use pipes connector to attach them (check photos). But maybe you will find own solution.
- put new motor mounts (check the photos to see orientation).
And now you can put the belts. Check photos to see how. Tight them, do not cut them while not sure that all was assembled right. Use plastic ties to fix the belts. Adjust X belt holders positions to be sure that all belts are parallel.
As for Z endstop - I use top mounted endstop for Z max + BL-Touch.
Last thing, changes in firmware - use amount of microsteps as for regular GT20 pulley movement and multiply it twice (as we have pulley block on Z). For regular 1.8° stepper motor it is 80 steps per 1mm for 1/16 microstepping, so it will be 160 steps per 1 millimeter with 1/16.
Try to use as much microsteps as possible with your drivers for Z, especially if you use auto level. LV8729 drivers probably will be the best for this - I use them 1/64 microstepping.
Do not put high speed for Z on 8bit boards - I use 20mm/s for homing and 40mm/s for movements with 1/64 microstepps. Of course speed can be higher, but it just don't need to be really high.
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