ge_rik wrote: ↑Thu Nov 26, 2020 7:33 pm
I like the idea of the functional leaf springs. Would ABS be more flexible than PLA do you think?
I'd be very wary of trying to make plastic springs work reliably. Especially the polymers available for home printers.
Flexibility and springiness are very two different physical properties, the relevant measurement is Young's Modulus and polymers have very low results.
The other problem with polymers is that they creep under load. It takes time, but over months the shape of the spring will change. We found acetal was the best injection moulding polymer for making springs, but I've seen that creep over time.
If you want working springs, design the print to use phos bronze strip/wire, or music wire, as the spring element which can be threaded through the axle box print and hidden behind the dummy springs.
I have a vague memory that something like this was available in P4 in the distant past when I still read MRJ. Probably based on a fold-up etching and suitable wire, which was the high tech of the time.
The model looks good so far and given your interest in the Southwold, I hope you can get it to run in Cleminson form.
Regards,
Graeme
