Wednesday, February 25, 2009

Bentech Step 2

The main tube has been shortened, I marked the centerline of the sides of the tube, marked the head tube points, center-punched them, used a 1/8" drill bit and drilled pilot holes, then used a bi-metallic holesaw with a 1/4" center bit to drill from each side ...
to drill out the hole for the head tube.

Here I've tack-welded the head tube into postion. You may be wondering how the decision was made as to how much of the head tube would protrude above or below the main tube ... I took off the front end clamps, loosened the 2 clamps to my right, rotated the front end of the main tube 90° up, tightened down the 2 clamps to the right, inserted the head tube so it rested squarely on the surface of the jig ...
I tacked on one side, then directly 180°opposite on the other side. Then the two opposite ones for front & back.
The white u-bar will be the bracket for the chain guide idler wheels.

Here's a view of my welding ... dressed up by the hand grinder.
The head tube is now firmly in place.

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