Multimaterial print

Hi OFM community. I am experimenting with multimaterial prints and made this fidget toy using TPU hinges and PLA. I was wondering if anyone has experimented with TPU to make the X and Y hinges of the OFM body. Will this increase the X/Y axis motion range?

1 Like

Potentially the motion range would get (a little) bigger if we used flexible filament for the hinges - but the design intentionally limits the angle of the flexures to what’s safe to achieve with PLA. It would, in theory, be possible to move the limits of motion to take advantage of more flexible hinges. I’d be a bit worried, though, that more flexible hinges lead to the motion becoming less accurate: it might be able to move further, but it might not stay as flat and there would most likely be worse drift and sloppiness so it isn’t a silver bullet.

I think in general flexible plastic is brilliant for large-angle flexures, but for small-angle flexures like the ones we want, it doesn’t give as much of an advantage as you might first think.

I have generally shied away from multi-material printing because it also excludes the vast majority of 3D printers. However, if you’re able to figure out how to make the flexures out of something else, I would be curious to see how well it works. I may even be able to put together a long travel microscope based on more flexible flexures (i.e. remove the limits on range of motion) though I can’t guarantee such a microscope would work all that well… The easiest way to test would be to modify the feet (or stick something between the feet and the body) to allow the legs to bend downwards a bit further. If that works nicely, further investigation might be worthwhile.