Holes are small, any tutorials to adjust Cura to get accurate hole sizes?

[cptanpanic 1]

I have a new Prusa i3, and have it running. I have done some calibration stuff, including measuring extrusion distance, but have not adjusted extrusion percentage. Anyone have a tutorial, or steps so I can get adjust Cura to get accurate size holes, for example I made a part that had 5mm holes and posts. The posts did not fit in the holes. The holes were like 4.5mm.

Thanks,

CP

 

[IRobertI 521]

There was a thread about this just the other day:

http://umforum.ultimaker.com/index.php?/topic/5902-very-small-circles-are-filled-um2/

 

[aaronalai 2]

Hey CptanPanic, regarding the holes; I think that's trial and error. Myself and others have found that about 0.2 mm of shrinkage occurs in many PLA's. For holes I add 0.2 mm to the radius of the hole, making the diameter 0.4 mm larger.

 

[Daid 306]

Could also be that your machine has backlash, be sure to check that first, with backlash in the machine you'll never going to get accurate results. (I find a 0.5mm difference a lot for 5mm holes, hard to think that that just shrinkage)