Is there a bounty site for 3D printed parts design?

1. Someone creates a bounty w/ initial #bitcoin pledge & design spec

2. Others can pile up & add to the tip pile

3 Someone proposes a claim to the bounty w/ design

4. Bounty creator accept(/deny)

5. Designer gets paid

6. If time expires or bounty creator gives up, all the pledges are released to depositors

DLCs can do this with lightning