ready to print chain mod

This is a remix of the awesome tracks https://www.thingiverse.com/thing:2393975/ for Bryant87's RC Speed Tank. http://www.thingiverse.com/thing:2024364

I simply laid out 44 chains and 88 grooves on a single platter, because most slicers don't pack very efficiently.

Update: after some testing, I found 2 problems:
- the chain is fairly weak (printed in ABS)
- the inserts, which I printed in flexpla, dont stick very well, even when glued with epoxy

So I made a modified version, which