Whenever I try to print designs with interlocking parts, such as http://www.thingiverse.com/thing:30981 , I always find that the parts won’t mate – both sides are too big by about 0.25 - 0.5 mm – and I wind up doing a lot of work with an xacto knife to get even one set of parts to connect. Something like http://www.thingiverse.com/thing:1276095 cannot be printed at the default size and come out wiggly – the parts fuse. I have to print it larger to get it to work. The printer seems to want to color “outside the lines” a bit.
I had for a while presumed the problem was with the accuracy of my printer itself, but when I went to the Aleph Objects open house the other night, I saw lots of mechanical things that did not appear to have been laboriously shaved down the way I have to do. So I can only presume that I am somehow using it wrong.
I am for the most part printing on the default profiles cura gives me, using HIPS. Do I need a smaller nozzle than the default 0.5mm one? Do I need to use a particular filament? Print on slow settings? Is there an expert “color inside the lines” setting somewhere? Or perhaps this is better asked in the reverse – what do find you have to do to make mechanical parts work?