Look at the design page for info on the plywood velomobile construction.

Monday, 30 July 2012

Jig saw puzzle connection !

paper model
I think have found a new way to make (or approximate) compound curved shapes with flat sheet. Plywood material is flexible and can be deformed to a compound curvature. On my computer I have modelled a spherical wheel cover consisting of 7 pieces. They will be connected with jig saw puzzle joints. I have deformed the piece on the computer to a flat plate. The picture shows a paper model. I hope to present a model in plywood soon. The jig saw puzzle joint can be produced easily with laser cutting machines and I expect the assembling with some glue is easy too.
Easy connecting with the jig saw puzzle connection. The curved sides will deform the flat plate into a sphere segment.

Summerlab was OK

I presented the plywood velomobile to on the Summerlab in Nantes. Watch the video. We tested the machine. The seat, the front suspension, the soft top and the chain guidance were failed or considered inadequate and than repaired and improved. Thank you guys!

We have thought about how the plywood sheets can be attached. Below you see a sample.

provisionally attached with staples...

glued with wood construction glue (foaming PU)

will we ever get these staples out again?
To get experience we tried to make a hard top too.

The chain is guided by four toothed chain wheels to reduce the losses up to the max. But it would easily derail from the rear sprocket because it could not be tensioned properly.
Jacques and ? (sorry I forgot your name) are adapting the wheel mount so the chain can be tensioned properly
Joris wanted to make a one wheeled trailer (remorque). I showed him my plywood design. Building a simple trailer was a fine way to learn (developing the sheet, bending the alu tube... )

Joris has made a mock-up to evaluate the shape and generate the development of the sheet

unwrapping the sheet
The edge at the top of the trailer will be reinforced with a tube. Bending it is not so easy. Because we did noty compensate for the elastic relaxation the tube did not get its definitive form directly...

bending aluminium tube Dxt 18x1

for the last turn we fix at a new position the tube so we can release the first par

oops ! We should have filled it with sand...
But not only details were studied. Scale models and a 1:1 mock-up was made too:

On the wiki you will find some more !

The summerlab was a very pleasant gathering of interesting people and thoughts. Although not presented at the summerlab and already written in 2004 to me the most intriguing was the philosophy on cyborgs of Natasha Roussel.