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Thursday, 6 September 2012

Frame Stay Tooling & The First Bent Stay!!

The next step in the build has been for a while to pluck up the courage to start practicing with bending the tubing for the seat and chain stays.

This has been for me the most intimidating part of the build as it was the part I knew the least about and the lack of information on the Internet regarding techniques other people have successfully employed only served to make this task event more daunting.

I did find one picture of a stay bending setup on the net which was comprised of a set of form tools mounted in a fly press. This seemed pretty simple and after a quick chat with Piet (now my full time wood turner and general jig building consultant!!) we decided on a plan to make a set of tooling.

The picture below shows the turned piece of wood which will be used to form the basis of the bends in the tubing, for initial tests this will be mounted in a vice and the tube pulled around it to form the bends,

Turned Wooden Form Tool & Bar Clamp
Because I was so keen to test the tooling and also wanted to see if I could get away without needing a fly press I modified the turned block to incorporate a clamp to hold the tube during bending.

The next step was to have a play with bending a tube.

Tube Being Bent
This technique definitely requires some honing however the results of the first bent tube were pretty encouraging.

Chainstay Number One!!
At the moment these test pieces are being done using cheapo seam welded tube of the correct diameter. I need to do a couple more tests to accurately determine how far the centre of a bend ends up being from the mount in the form tool and I should be good to go on the real things!!

Next up should be a finished set of stays and even maybe all the bits on the jig ready for some brazing action!!

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