Thanks Dirk - Sounds great. I really love this idea. My inseam is 86 cm and I herewith order one of the first prototypes.
What, if you use light plactic tubes instead the steel ones? The CF-wrapping might be sufficient and you won't have corrosion problems.
Cheers, Jürgen. On 29.04.2011 14:35, Dirk Bonné wrote:
Attached is a drawing of such joint. It would connect 3 tubes at 90degree angles. On 29.04.2011 12:21, Dirk Bonné wrote:A week ago I came across the reprap project (reprap.org), which is an "open source" 3D printing machine. Such a printer can print pieces of plastic, supposedly in any form as long at it is limited in size. I'm very much tempted making such a machine for my self (as winter project). One idea I have is to build a bike (e.g. python) using the reprap. The goal would be to build a trellis-framed python, like my own bike (pythoon) and some others seen on the project page. I would still use regular steel tubing with small diameter (8-16mm), but the joints connecting those tubes would be printed plastic bits that are pressed inside of the tube. The construction process would look like this: 1 design all the joints connecting the tubes. 2 print them -> results in "inner lugs". 3 cut the metal tubes to the right length (tube cutter). 4 assemble the frame by pressing the plastic joints in the tubes. => at this point I would like that the bike is stiff enough to hold itself. The next phase would strengthen the bike by wrapping uni-directional carbon fiber around the joints (like using a tape roll wrapping it around forming a "outer lug": 5 paint the tubes with a primer before wrapping the CF around 6 cut the roll of unidirectional CF in long strands about 1cm width 7 use a brush dipping the CF with epoxy while wrapping it around the joints firmly connecting the tubes to the joints. What I hope the advantages would be: * sharing: possible to share the design between people - anybody with a 3d-printer could produce a bike. It would even be possible to make a program that given some parameters can produce a custom measurements. * easier/quicklier: the tubes are just cu wih a plain tube cutter tool. There is much less measuring and filing involved (making a trellis frame can really be horrible - especially when brazing where precision means all). * easier: no need for a jig. The joints would make the frame pre-stiff enough to easily adjust the frame as a whole using a measuring stick. * equipement: no welding/brazing equipement needed (ok, you need a 3d printer....). Other directions: the same process would be useful for a pure CF-bike or may be a bamboo-bike... What is your take on the idea? Is there ny around iwth experience with 3d printing product?. Could it work? Would there be a real advantage? DirkB PS: with the reprap I discovered there is a 3D CAD for programmers: OpenSCAD. For those with the programming ability, it might be alternative for autocad and the like. ============================================================ This is the Python Mailinglist //www.freelists.org/list/python Listmaster: Jürgen Mages jmages@xxxxxxTo unsubscribe send an empty mail to python-request@xxxxxxxxxxxxxwith 'unsubscribe' in the subject field. ============================================================------------------------------------------------------------------------
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