Prototopea
June 2016
Arising from the need to calibrate and test the limits of a CNC milling machine, this bike stem was born. This part was crafted out of 7075 aluminum round stock. There is a 10-degree upward slope providing maneuverability and an overall length of 104mm to accommodate taller riders. Additionally, hexagonal holes provide removable fixturing for other utilities (i.e. phone mount, cup holder, additional lights) while also preventing rotational issues while riding.
Several different' geometries were tested. Eventually, the design shown accommodated better maneuverability and fit with exist parts better.
This was a bit of a last minute job but it worked out super well!
I started with a large piece of brass that cost $450! I slowly drilled out the holes and milled out the larger ring and internal puck. The brass machined really well and had a nice profile finish. Threw both parts on the lathe and cleaned up the burs and the second side. To hold the larger ring, I ended up using the 3-Jaw chuck and clamped from the inside. It held pretty well but I took small 0.007” to make sure nothing got pushed too much.
From here is went to Gregg Gemin from Gemin Fabrication and Victor Soloman from Litterally Balling. You can see what came out!
While welding up my bike, I decided to make a few more components. Here is milled a bike clamp from some 6061 Alumuinum alloy. I ended up making two because I didn’t drill a large enough clearance hole for the bolt to really allow the clamp to clamp!
If you are interested, I made an in instructable of my design and CAM process. Check it out!
This a small batch order I made for a client. There were about 160 parts in total. Mostly 6061 but the gold parts were a 954 Bronze. It machined pretty well and left a great finish.
