Hello, I have Anet A8 and problem with printing.

3D Printing
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Hello,
I have Anet A8 and problem with printing. When I print something like washer 20mm outer perimeter and 10mm inner hole, outer diameter is in 0,1 mm tolerance but inner hole is 8,5mm, its 1,5mm less. Does anybody has any suggestion what should be wrong?

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First things to check always are that your Steps-per-MM settings are correct (X, Y, Z, and E), that your hot end isn’t wobbling in its mount, and that your pulleys are fully secured via set screw. Additionally, including some pictures might give us a hint as to what’s going on as well.

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adjust your steps per mm value of x and y axis…and check again…

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@For_Everyone If the steps per mm were significantly off, wouldn’t the outer dimension also be off similarly to the inner one? Miro states outer is correct.
I actually have the same problem but with my poor old twisted Printrbot LC it’s not worth tuning - I just make the holes larger :blush:

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I had the same issue even after I had all my steps/mm dialed in. I found that I could mostly eliminate the issue by adjusting my nozzle diameter. I did this by setting my nozzle diameter (in slicer settings) to the nominal value and then adjusting the extrusion multiplier until I achieved correct single wall widths. Then I did some math and calculated the size nozzle that would give the same effect for an extrusion multiplier of 1. Using that nozzle diameter and extrusion multiplier of one fixed most of my issues. Note that if I had the nozzle diameter set to nominal (0.4mm in my case) and used a tuned extrusion multiplier I still had size issues and other extrusion related problems. So, take from that what you will, but it seemed to work for me.

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@Daryl_Bond Thanks for suggestion I will try it

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Is ur inner diameter round if u measure it at different points?
I rly never heard about that much difference from inside to outside diameter. 1.5mm is nearly equal to 2* of ur nozzel with when printing a diameter. maybe u have some more problems that lead to it…
Check ur print quality, 0.06mm is perfect, to high value and small diameters wont get printed round.
Also ur extrusion width on outer perimeters,
to big and everything will get bigger, outer diameters not that much then inner diameters. If u slice by urself and use Slic3r look if ur extrusion width is written in mm not in %. If % set everything to 0.4(or whatever ur nozzel diameter is)

Then do a test print 2Outer diameter 20mm and 10mm and inner diameter 2 15mm and 5mm, also a cube outside 2020mm inside 1010mm, high enough so u can measure it good.
If u still have that problem when everything is set right i dont know what else could make that much difference.
Wish u good luck.

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Following up on what M Wie said: if your hole is circular and you don’t have fine enough angular sampling, the line segments defining the perimeter will be in the area occupying the area you want a hole to be in. Ie, if your circle is sampled at 90 degree intervals, the actual hole will be the largest square that can fit in a circle of the desired diameter.