DIY PDW Bindle Rack, Try 2

thingiverse

See: http://www.thingiverse.com/thing:2069378 I never actually tested this DIY PDW Bindle rack adapter I designed. It was primarily for documentation purposes and anyone who wants to continue where I left off. My goal was to create a DIY PDW Bindle rack by repurposing a cheap bike rack's platform and attaching it to the bike. To achieve this, I attempted to make an adapter that would secure a bolt perpendicularly to all other bolts on the rack. Unfortunately, I never tested or assembled this design. Therefore, I strongly advise against building it, as it will likely fail even with favorable printing orientation. Assuming a 20-pound load on the rack and pushing it from one end (with a length of 20 inches), the concentrated torque on this single piece is too much. If you decide to machine this part from metal, you'll significantly improve its performance. If you do choose to print it, consider making an extra copy as I wouldn't trust a printed version. Here's How I Designed This: I took inspiration from the Bontrager BackRack (http://www.trekbikes.com/us/en_US/equipment/cycling-accessories/bike-racks/bontrager-backrack/p/14631/). I removed the legs from this used rack, which I purchased for $2.50 since it was missing a stay. To account for potential dimensional inaccuracies, I aligned slots with holes on the rack's platform. I also added drop-in nut features to prevent nuts from rotating when bolts are tightened. Assembly & Materials: You'll need: * One Bontrager BackRack minus its legs * Five 5mm bolts * Five 5mm nuts * Two 4mm bolts and two 4mm nuts, or one extremely long 4mm bolt with two 4mm nuts The 5mm bolts/nuts secure the adapter to the rack. The 4mm bolts/nuts attach the adapter to the bike. You'll need seat stay eyelets (I wouldn't trust P-clamps). Alternatively, you might be able to use: http://www.thingiverse.com/thing:1962052 or http://www.thingiverse.com/thing:1961983 (likely this one) However, machined versions would be significantly better. A very long 4mm bolt might bridge the gap between seat stay eyelets and provide added stiffness, but it's unlikely to work due to the required length of around 4-5 inches.