Wall Placement

[msurunner 2]

I think this is a SF issue, but I figured I would check to see what you guys thought and if there was a fix.

I'm getting prints where the walls aren't where they should be and thus the parts dimensions are off as are the infill connections. Here are a couple pics to illustrate my "failure".

As you can see, the hardware side of things appears to be fine, else you would see the "failure" in other areas. Also, though the part is drawn at 19 mm cube sections, the part next to the failure measures about 19.2 mm while the rest of the 19 mm pieces measure the 18.8 you would expect from shrinkage. THOUGHTS???

[IRobertI 521]

I have no thoughts or solutions for it but I can confirm that I've seen the same behaviour as well (although not quite as severe). When it happens it is always on parts similar in shape to what you show here. I don't have any examples handy as I haven't been printing much the last few months. I always figured it was just my machine, maybe that's not the case then.

[phut 0]

Tensioning the belts would be my first port of call as such behaviour is attributed to loose belts.

The other port of call is try another slicer program.

The overall dimensions - all parts will have some shrinkage. You will find the printing order (perimiter->infill-> loops etc.) will affect the way the overall dimensions vary quite signficantly. The best way is to use a path plan that give you your desired surface and strength properties (or as close to) then bump the dimensional tolerances on your model to compensate for the final bit of variation.

[fluxline 0]

I agree that the second picture shows that the infill not meeting the wall looks like a belt backlash problem.

The first picture shows that the cube on top of the 'L' shaped piece looks like it is stacked rather than the walls being flush. If that is the problem you are describing, it almost looks like the original model has that in it, maybe the outside walls are not seen as one surface but two distinct ones. Maybe the top of one does not match the bottom of the other? How does it look when you slice at look at the path, does it show a separation or flat surface? What are you using to slice it?

[peggyb 171]

maybe you can try to rotate the model 90 degrees and see if it happens on the same side or rotates along with the model.

you can determine if it is a machine/design/slice failure

[Daid 306]

It's a mechanical problem. You have backlash somewhere, most likely short or long belts.

[msurunner 2]

I have a hard time thinking it's backlash since it only occurs in the one part of the print and it exceeds drawn dimensions in only the one area, not in the smaller square on top where the machine would have to make quicker movements... But I will double check my short belts, the long ones twang.

[billdempsey 0]

I had exactly the same thing happening on one of my prints. I loosened the pulleys on the X Y motors and tightened them back up. That got rid of the little offset.