May 09, 2011

Tacking and lock a frame - フレームの仮付けと固定

Tacking is the first welding process after cleaning a tube set. We set the tube set on a frame jig and tack it. There are several ways to weld a frame. In Seven, we tack the whole tube on a jig. Probably, in some frame manufacturers, they weld each front part and back end separately.
We cannot say which is better. Frame alignment accuracy doesn't depend on the way. Anyway, after tacking, we lock (long tacking) the joint parts of the frame because we don't want the tube to move by welding.
However, there is a careful point to lock the joint parts. That is I have to weld with paying attention some stress which the tube will have in a frame. By welding, sometimes tubes have a lot of stress in a frame, but you cannot see it. It sometimes causes a crack after lots of riding.
So I always give a stress-free spot in a frame. I do not lock all of the joint part of the frame right before welding. That is my way of tacking and lock a frame.


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