Day_six

The Penn State Six Pack

Day Six.. Rear Triangle, Align and Tack

Rear end of frame. Ready to mount rear triangle jig.

With 2" channel, a rear triangle jig is made and welded
to the rear seat support. (not to the main jig).

Utilizing the same ideas as in the seat tube supports, the rear
triangle jig is manufactured.. The step down in the channel
allows for the bend and drop in the stays. A "dummy" axle is
mounted to hold the rear dropouts and to support the chain
and seat stays.

The rear triangle is mounted

View from the chainstay side (bottom) View from the chainstay side (top)

The frame aligned and ready to tack.
This alignment is just checking all the tubes and making sure
they are aligned to each other and straight. If they are not
then they are moved to where they belong and checked again.
If they are wrong after tacking, the tack can be cut and the
tube re aligned. This is an important step because they must
be right before welding. It could cause a costly error and
may trash tube or the complete frame. It is much easier to
cut a tack rather then a complete weld.

A tacked joint.