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@xxxxxx > > To unsubscribe send an empty mail to > python-request@xxxxxxxxxxxxx > with 'unsubscribe' in the subject field. > > ============================================================ > >
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