An idea during a print - and another universe opens :-)
Sounds like something from the '70s but is from 2011.
This morning I printed another mendel spring. When removing it from the glass printbed it jumped on the x-axis belt.
In the dark corner, where my printer is placed, the soft PLA and the belt looked the same color - even if the one is more light grey and the other one more blue grey.
But this similarity encouraged myself to copy the shape of the belt with soft PLA. OpenSCAD again proofed to be very good for things like that. I made a singel pattern of one tooth and the following gap and copied it 20 times.
The print was amazing - it was strong, it was not springy as expected - it streched not even with force.
The comparison to the original showed the possibilities of soft PLA:
This was the proof of principle. Then I designed an endless belt with 76 teeth - 380 mm length. The best of all: This is not even a quarter of what is printable!
I tested the printed endless belt with a few mendel parts fixed to my desk. I tensioned it with force to test, to see if you can tense it like the belt on the reprap machine.
With this 380 mm belt the gears worked perfect. It was as intended, it was strong.
When testing the limits of the belt it broke with brute force - but it was hard to break it!
The belts in the reprap machines are with steel wire inside to prevent them from stretching. The soft PLA belt is not comparable to these belts. But I was deeply impressed by the stability of the printed belt.
The possibilities are nearly unlimited. I think about printing tires for RC cars or chains for a RC tanks, button covers for electronics, belts for transmissions, springs, etc.
After little initial problems with soft PLA I'm now convinced. Soft PLA brings a lot of fun!
The objects can be downloaded here as usual.
If anybody want's to try this soft PLA - here you can order: www.2printbeta.de
Greetings from the lake of constance