3D printing to the rescue
2012-02-25 21 Comments
I bought a new bicycle, recently. My first with drop-bars. The additional brake-levers ease my mind, but make it more difficult to attach any more stuff. So I went looking for a well-reviewd, certified (German Straßenverkehrszulassung) headlight with a clamp that would fit into the space right next to the stem.
The Busch & Müller Ixon Pure seemed to fit the bill. It comes with a too small clamp, but a larger one can be bought separately. Only after doing so, I realized the the lamp is put on in the opposite direction for this oversize clamp! This means the business end has to be in front of the bar, where I do not have enough space thanks to the cable connection-thingys of the brake levers.
What a great opportunity to see how far the Free Software parametric solid modeling application FreeCAD has come! The 0.12 release didn’t cut it, but with a checkout a while later, I managed to model what I call the sled, with the relevant part put on in reverse. There were a few issues I had to work around, but except for some fillets I had to do without, I suceeded. Not production ready (not that anoyne claimed that), but very promising. Kudos to the developers!
After having a quick look at the mesh in Blender, I went to shapeways.com. They claim their strong & flexible material can be used for living hinges and springs, and as far as it is required in my case, it works fine.
The quality of the surface and the corners is not great, but aside of the those ridges on the lever, overall precision seems to be excellent, as far as I can tell with such a small part. It fits very tightly, but so does the original.
The original sled has a metal inlet for the screw thread. I simply modeled a tunnel with the smaller diameter of the screw. Required some force to screw it in but seems to fit well now; only time will tell if this is a durable connection.
It took 10 days from order to shipment, $ 12.05 for the part and $ 11.31 for shipping, resulting in € 17.73. Edit: The model available for printing or download.
From a pure filling a need point of view, this was a bit expensive in time and money, but I just had to try it and enjoyed the process. On to a future with free/open modeling tools, model libraries and affordable 3d printing! :)