Hi guys,
trying to figure out why I’m getting internal dimensions larger by 0.2mm while outside dimensions are perfect.
ABS or PLA makes no difference. Using Repetier-Host with SLicer.
Any ideas, I tried using Repetier’s ’ External Perimeter First which still gives me same results.
I did not modify X,Y steps at all just what is supposed to be for my stepper/belt/pulley.
This very good post by @nop_head may help explain the difficulties in FDM 3D printing (check his links, too):
Thanks @Carlton_Dodd that is very interesting. I already printed with exterior perimeter first so I’ll have to try other programs.
@Milos_Vajdic Recent versions of Slic3r make use of nophead’s flow reduction formula for perimeters.
After reading his post I am messing around with perimeter filament widths as I believe that is where I am running into trouble. Will report if I’m on the right track.
I am also researching this problem. As @Neil_Darlow said, Slic3r does use a good approximation model which you can see here http://manual.slic3r.org/advanced/flow-math. If you check your gcode and do the math, you will see that the part should come out correct.
I would suggest looking at the filament diameter value you use in Slic3r.
Commenting to see the solution, as I have the same problem.
I spent a few hours messing with Slic3r perimeter width line settings and if manually applied you can get close results to perfect, but to manually do dozen of tests to get the right amount seems…ridiculous.
Slicer does have the XY size compensation but that just scales whole model in XY only which means external parameters will then be off.
no solution to my (our) problem yet.
I have the same issue.
Ok so by changing ’ XY size compensation’ in Print Settings>Advanced to negative value of -0.1 I managed to reduce internal perimeters by 0.2mm (0,1 on both sides gives me 0,2).
It did also reduce external perimeter by 0.1 but I’m ok with that. I think this may be the best chance yet.
Pretty sure its about tolerances, a 10mm peg cant fit in a 10mm hole. ±0.2 mm my xyz davinci does the same thing. I believe it’s how the slicer handles wall thickness from the stl.
@Jules_Hoehn nophead has suggested that you need to solve simultaneous equations for steps/mm in X and Y to reduce these errors.
My Mendel90 gives an interference fit for interlocking parts printed at the same size. You can feel the bumps of the perimeters sliding against each other as you push parts together.
