I must be doing something wrong.  Been printing parts for the reworked i3 and

3D Printing
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I must be doing something wrong.

Been printing parts for the reworked i3 and everything is practically possible to assemble without drilling out. I know many of the instructions say heat things or use a mallet, but it just seems too far off.

I printed a 20mm test cube that measured 20.1 to 20.45 (depending on side). I’m extruding at 95-100% and have measured the diameter of the filament to adjust accordingly.

This is a direct drive housing for an E3D v6, and there’s no way the hot end is going in without heating it or sanding material away.

Any thoughts?

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That’s quite a percentage out for such a small test object. I’d print something larger to check with. How about printing two of these, one along the X axis, one along the Y?

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The wobbly edges look like over extrusion to me. Check your e steps and measure your filament as accurately as you can.

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You might be overextruding a bit. You might be running a bit hot.
Holes being small is a known issue, you’re pulling melted plastic in a small circle and it’s going to contract. Also, “polyhole” problem, a cylindrical hole represented as triangles will be smaller than the original cylinder.

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Try printing external perimeters first, then internals. This tends to hold outside dimensions better.

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And for opening up holes with a hand tool http://www.thingiverse.com/thing:16956

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Also try scaling by a 0.3% shrink factor i.e. 1.003 multiplier.

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thx guys, this is all great input. here are a couple things regarding some stuff I’d already played around with…

For @Eclsnowman , I have been playing with upscaling a bit (like 1.03%) and this helps quite a bit, but for items like this that mount to the steppers, the holes are now shifted off center by about half the diameter of the hole (PIA).

@Richard_Mitchell & @Jeff_DeMaagd , regarding the high temps and crappy edges, yes, this wasn’t a good piece cause I was experimenting last night with different settings. I normally print PLA @ 200C but this piece was done at 215. My other parts have crisper edges done at the lower temp. The temp thing has always been confusing cause I normally print as low as I can go but I’ve seen other people swear by printing at 210-215 whereas I sometimes try to get by at 195 even.

The extra perimeters is a good point because it’s set to 3, so I play with that setting.

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@Tim_Sills 1.03 would be 3%, that would be way to much I agree.

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Also, depending on what slicer you’re using, dimensions can be way off. KISSlicer for me, has completely spot-on dimensions, where Slic3r will constantly undersize holes, etc.

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thx @ThantiK , I’ve been using Slic3r so will try another slicer for comparison.

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Just a heads up, it also looks like you’re overextruding…a LOT. Follow this excellent guide by @Richard_Horne and get that set correctly: http://richrap.blogspot.com/2012/01/slic3r-is-nicer-part-1-settings-and.html

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yeahhh man :wink: