Weird layer misalignment / Homemade reprap

Hey everyone,


I am trying to calibrate my homemade printer(made from scrapheap, welded frame),
strange misalignment i have never seen such before.

The layers sometime sit perfectly on each other and some places(randomly) sit with slight offset, as you can see each time it changes the offset to different directions.

Belt is tighten well, Steps/mm is calibrated perfectly, printing at low speed.
Just cant get the reason to this offset.
any ideas?





appreciate your help!

Edited 1 time(s). Last edit at 06/30/2016 06:46AM by Itamare.

Z screws bent? Does it produce the same "wave" on all prints?

Judging by your pictures the problem is on your x-axis?

This is indeed quite odd. A logical conclusion is that each individual step is in fact not linear, but that it seems linear over a long enough distance. From this I also assume you calibrated the axis over a long distance, say 100mm or more?

What I mean is if you measure the smallest possible step on the problematic axis, you should see each step equal the previous step exactly in distance. This is what I suppose is not happening. Maybe you are trying to step a 0.9 degree motor with 32-step control?
Maybe the belt/pulley you are using on that axis is not manufactured 100% accurate (or it is damaged)?

As mentioned by jnsbanman, it could be that if your z-axis does not move up and down correctly (both sides by the same amount) it causes this symptom. Also, have you tried different prints/slicer settings?

Are you supplying the minimum amount of current to run the stepper motor? Just enough to make it turn should be adequate for functional use.
It looks like that print, of the boat, is designed to look like that IS the chimney not supposed to 'wave' like that? Sorry for that obvious question

I am brainstorming here, sorry if none of this is helpful.

Edited 3 time(s). Last edit at 06/30/2016 10:57AM by v1talogy.

Hey all!

Now that you have mentioned it i think its the z axis motor causes these issues, the coupler isn't perfectly aligned and i guess that it turns differently every step.

I will buy new couplers check it and update here ASAP.

v1talogy, the boat's chimney is designed by 3DBenchy, i don't think it supposed to wave like it

thanks a lot for you help!

Edited 1 time(s). Last edit at 07/01/2016 07:24AM by Itamare.