PVC tubes vehicle frame

[Ahmed]

Bamboo is more difficult to reach, as you note P. Schutt, but classic metal knots do the trick without requiring complex and unusual techniques ...

[chatelot16]

how to compare the price of pvc and steel? comparing the price per kg is useless: we do something more solid with 10kg of steel than with 10kg of pvc

with steel there are no unnecessary costs, we cut and weld! with pvc you need glued connections ... when you want to modify the connections are lost ... with steel we cut and reweld as we want

so for me steel is the simplest

with steel it is easily too solid: no risk that the prototype breaks in a demonstration ... with pvc it is much more risky

but it's not just steel: there is also the good old tree wood! the carts have always been made of wood: wood assembled with good steel screws keeps it upright!

the weight-to-strength ratio of wood is always better than pvc

the weight of the solidity of the wood can even be better than that of steel: it is not for nothing that many planes have been made of wood ... the problem of wood is aging, assembling which takes play when wood swells and shrinks with humidity and drying: good use of wood requires more skill than scrap

[Ahmed]

the weight / solidity ratio of wood can even be better than that of steel ...

This is also evident in the case of structural beams, especially those made of glulam.

[Philippe Schutt]

if you know how to weld and you are equipped.
PVC has the advantage of being accessible to all

[Ahmed]

It would be a mistake to oppose wood and steel: the two offer different possibilities, which it is wise to combine as well as possible.

[Flytox]

With a composite ... cardboard

http://www.youtube.com/watch?v=eEJ068Pzrj4

[Aumicron]

Regarding wood, for information, a photo published by Christophe:

[Forhorse]

the weight / solidity ratio of wood can even be better than that of steel ...

This is also evident in the case of structural beams, especially those made of glulam.

Especially since nowadays it is easy to make even small pieces of glulam.
All it takes is a few clamps, polyurethane wood glue and patience.
For my part I made myself the composite beams (called i beam) of my frame and I realize that the performance of some wood glues are such that it is possible to use them as the only means of assembly.

[elephant]

I had tried it myself, there are dozens of years pasting a surface of (about 7 X 10) of planed wood with the white carpenter's glue available at the time.

It is the wood that tears off, not the collage.

[cortejuan]

Hello,

what was nice in the idea of ​​grelinette it was the diversion of the product, (I am a follower of recycling) so the idea remains attractive.

The bamboo yes it is hypersolid but difficult to associate because it is necessary to find stems of strictly same diameter, to manage the nodes (or to file them) it is difficult to bend, in short it requires skill if we do not want that after a week all the joints are working.

I cultivate among other species of edulis bamboo (or giant or pubescent) I know the product well but to have an optimal resistance it is necessary that they are cut in the rules otherwise it is damaged, so it would be necessary that you get closer to a neighbor owning this product rather than buying it from forests managed in a dubious way (let's not forget that the disappearance of giant pandas is mainly due to the disappearance of large bamboo forests (especially edulis)).

Regarding the glues and foams suggested, these are often harmful products (except wood glues based on casein), polyurethanes contain isocyanates as harmful as chlorine from PVC, etc.

So all solutions have their advantages and disadvantages and staying in a pure green scheme is very difficult.

The example of the wooden motorcycle illustrates the horrors that can be achieved by diverting the materials (not to mention the weight of the machine) ...

I await with curiosity your choice which will undoubtedly be the right one after all this very rich discussion.

Regards