Help with Geeetech i3 pro b Acrylic edition.

[meyre76]

I recently got an acrylic Geeetech i3 pro b, i built it using the instructions and YouTube tutorials, and for the most part it works, however the z-axis constantly provides trouble. I manually adjust the z-axis so that its perfectly level, i use a spirit level to check and i measure the distance from the base to the beginning of the pole for the extruder to move along, i know they're at the same level so shouldn't have issues moving. Sometimes it works, it moves up and down the full length with VidMate Mobdro no issue, i can home it several times then occasionally somewhat randomly it fails, one side moves and the other stepper motor just makes noise and does not move, despite working a few moments prior. I'm really confused as to whats going wrong, does anyone have any suggestions to make sure everything is perfectly inline with one another? could it be the x-axis poles not being perfect? Any help is super appreciated.

[ralphlat]

This has been the a problem for me and I have found that a number of things can cause the problems you outline. Some suggestions are:
1) Are the linkage from the motor to the screw properly set up - make sure there is enough shaft and screw for the linkage to get a proper grip
2) Are the screws straight and the frame aligned - I had to enlarge the hole in the top acrylic mount to allow the screw to move freely
3) Is everything lubricated adequately - it amazed me what a difference wd40 made
4) Is the screw type correct in your settings - sounds silly but I went on for some time getting very tall, skeleton prints before I realised..

Check the forum for links to these problems - that's where i found solutions.

In fairness I should warn you that I'm still working at other problems and I'm no expert.

[Soadyheid]

Hi!

i use a spirit level to check

. A spirit level is of no use as the base of the printer may not be level. You need to measure each side and adjust each screw individually till the X-Axis is at the same height at both sides. I measure between the top of the Z motor plate and the bottom of the Z-Axis linear bearing bush., see picture.

Z_Axis_measurement.png (188.74 KiB) Viewed 2938 times

As built, the two brass "nuts" which run up and down the M8 threaded rod (or T8 leadscrew if fitted) are locked at some fixed distance apart. If the threaded rods/leadscrews have any bends in them (and they probably will have!) the distance between them will change as the screws turn, this will cause binding, which in turn, will cause one or both of the Z-Axis motors to stall. This causes further binding between the nuts and screws and everything grinds to a halt.

A solution is to print off an anti Z-Axis wobble mod https://www.thingiverse.com/thing:1821976which, when fitted, allows the X-Axis to float on top of the "nuts" rather than being rigidly attached. any slight bends in the threaded rods/leadscrews no longer causes binding and motor stalls. Note that if the bearing rods aren't reasonably straight, you may get something similar happening as well!

Hope this helps!

Play Bonny!

Soadyheid.