Almost-impossible-3D-test-print

thingiverse

This print will put your slicer and printer to the test. Triple Bridge Block It's tough for the slicer to figure out how to slice this right. It is possible to make the bridge test, but no slicer I've tested has managed to get it right; however, it's very easy to print this with support - but that's cheating! Don't expect this to work perfectly, as no slicer I've tried has been able to fix it. This is a challenge for the future or with a bridge. 45 Deg Print Printing at 45 degrees without support can be done with almost all 3D printers. What makes this more difficult to print is that it needs to make a "jump" when printing in 43 degrees, and not hit the roof beneath it - no filament or stringing should touch the roof of the hangar! This is doable with most slicers and filaments. If you're having trouble, check if you're printing at the right speed and not too high temperature. Printing at too high a temperature makes your filament "sink" too fast, which prevents bridging. Smooth Surface The pit, back of the hangar, should be smooth, with no stairs! Some filaments are better than others for this, and lowering the slicer height to 0.1 or smaller will get you a smoother surface - but that can affect other objects on the print negatively! If you get "stairs," try setting your slicer to 0.2; most of the time, a smaller slice gets a better surface, but not always - you'll have to test. Size in X-Y Size matters! Take out your vernier caliper and measure it: 40 x 60 mm ± 0.1 No More! This is VERY important if you're making a box with a lid or something that needs to fit with other parts - then your dimensions matter. Don't think you can get away with using an ordinary ruler; you won't be able to! This can be tricky, and you might need to compensate in your slicer (Slic3r) or ROM settings, your X and Y steppings. Fast Example: My ROM X Stepper settings = 80.421 When I measure my test print, it should be 40 x 60 mm but I got 39.7 mm Then the math: Size (What you want it to be) × Your ROM Step / Size you got. (40 × 80.421 / 39.7 = 81.028) So just put 81.028 in your ROM and do a new test print! This can also be done with G commands. Hole and Edge There should not be any crack or small gap next to the hole. If you see a crack or gap, check your extruder or Extrusion multiplier in your slicer. Roof and Horizontal Hole The roof on the hangar should be smooth and round, and the hole through the hangar should be round. It's hard to print at more than 45 degrees, but this is a relatively small hole, so the printer can "bridge" print the roof of the hole. If you don't get a nice print, maybe you're printing too slow or with too high temperature, or you need some cooling fan.