Archive for November 4th, 2015

Tiny Cylinder Test Object

A discussion on the M2 forums prompted this test object:

Tiny Cylinder - 0.9x9.0 mm

Tiny Cylinder – 0.9×9.0 mm

Sliced with Slic3r for PETG at 1 mm/s, with fans in full effect. It sits amid a 5 mm brim, inside a skirt that uses 15 mm of filament, giving it a Washington Monument aspect.

The challenge was to print a 0.7x9.0 cylinder, which doesn’t work well with a 0.35 mm nozzle. Instead, I went with 0.9 mm diameter. The result measures 1.1 mm over all the obvious bumps, so it’s surprisingly close. The “nail head” at the bottom most likely comes from the hot end depressurizing as it suddenly transitions from 15 mm/s in the brim to 1 mm/s for the cylinder.

Fairly obviously, you can’t print something like that at full speed (50 mm/s was claimed for a Rep 2 and I don’t believe that for an instant). Indeed, it’s such a pathological model that Slic3r’s minimum layer time and small perimeter settings had no effect; I had to manually set the extrusion speed to 1 mm/s in order to make it work. Plus adding that brim, because I knew it wouldn’t stand by itself.

Other than that, printing it was no big deal.

A picture from that M2 forum discussion suggests you can go crazy with this stuff:

20 mm, 40 mm, 60 mm and 120 mm

20 mm, 40 mm, 60 mm and 120 mm

The OpenSCAD source code for my version:

cylinder(d=0.9,h=9,$fn=8);

There, now, that wasn’t so hard, was it?

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