SOLVED Offset Print Problem

[mike-truly 2]

Went to check on a 3D print this morning and found the print mangled with PLA everywhere.

I had some medallion-like objects 4 up on the build plate. They were printing fine when I left them but at some point, all 4 started printing offset about 26mm towards the front of the bed.

Any idea what would cause this offset?

Thanks!

Mike

PS... how do I delete an image uploaded to the image gallery? (I accidently uploaded a hi-rez image).

[mike-truly 2]

Oh, and I should mention that out of the 4... only one medallion had been knocked out of place. The other 3 appeared to be in their original location on the bed. (The 2 shown above were part of the 3 in their original location. I even had to scrape these 3 off the glass with my scraper so I'm pretty sure they didn't shift toward the back of the bed to get this offset).

Thanks!

Mike

[kmanstudios 1,044]

I am thinking that something got banged while printing. If the printhead is knocked hard enough while printing, the printing rods (X & Y) can be knocked out of alignment. This could happen if it hit a hard, curled up part.

I have had it happen in such a way that it has knocked my plate loose from the clips. It is rare, but it can happen.

[mike-truly 2]

Thanks for the info! Good to know.

I cleaned up the mess, cleaned the bed and the subsequent prints have shown no shifting problem... weird.

Thanks again.

Mike

[geert_2 369]

It could also be that the X and Y stepper motors did miss a few steps, when they hit something. They have no feedback, so they don't know where they are, they just count steps. And thus if they miss a few steps, if they can't move due to too much friction, all the rest of the model will be shifted.

[kmanstudios 1,044]

It could also be that the X and Y stepper motors did miss a few steps, when they hit something. They have no feedback, so they don't know where they are, they just count steps. And thus if they miss a few steps, if they can't move due to too much friction, all the rest of the model will be shifted.

This may have been what I was trying to say. For instance, it has happened when my slow hands are trying to get out of the way and are hit. It knocks it out of whack. But, when it re-homes, it sets things aright. It has happened when the print gets knocked the same way.