Hi all,
I have done a model called Ring'n'Roll, basically two nested rings that can roll one inside the other, and I was wondering how to position the 2 moving parts in the stl file before printing.
Actually, for the initial model the regular Ring'nRoll I turned the internal ring of 90°. My goal was to minimized the area of contact between the two rings, to avoid they get fused (the thickness is 2 mm and the clearance 0.75). I already ordered it in Alumide in this position.
But I am now wondring if, depending on the printing direction, there could not be a deformation that could occur differently on each ring, and prevent them from moving freely.

So for my next model (not ordered yet), the Ring'n'Roll with Holes I decided to keep the 2 rings lying flat on the horizontal surface.

See the automatically generated thumbnails on these models, or this rendering:

The first one is "flat" the second one "turned at 90°".

What is you opinion or experience on this topic?

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[Updated on: Tue, 16 November 2010 06:38 UTC]

Cool! Great minds..

I've been pondering the same principles/problems:



Despite orientations, too much deformation could always kill the principle.
And even when built with 0.6 mm clearance, I think, in WSF it might fuse.
On the other hand, I'm afraid the clearance might even be to much and cause to much jiggle.

One of the options I'm trying, is using a lot of small bulbs on the outside of the inner sphere or the inside of the outer sphere. Might even be able to cheat a little with the clearance then.

Would not really work for a version with holes though

Very curious as to how you Alumide model turns out!
I've been putting of ordering the sphere, afraid of an expensive disappointment

Cheers

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It arrived!



On my side, I planned to have 3 layers and also to add gears!
Stay tuned!

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[Updated on: Tue, 16 November 2010 06:58 UTC]