The Chopper Compendium

I have a question about purpose of the CBH and CSC frame jig top rails (the 1/2" by 2" flat stock which lays on top of the main rails of the jig)

Are they there to keep the rails straight and in line with the center line?

Can we do without them?

I'm using a heavier wall than normal for the main rails (.25" wall because it's what I've got) but I've noticed that even they aren't exactly straight and true. Flat stock on the top makes it even heavier and brings up the cost so I'd like to do without them, but not at the expense of precision.

What are peoples thoughts on this?

A jig can be a straight chalk line on the floor or made from wood.

So, build your jig however you want just make it striaght when done.

A tube is not always round or square as it is extruded when made and rolled by a machine. That is the one reason fo the top 1/2 plates to give a more parrellel suface.

No you do not have to have them!

go thru this thread and you will see some of the many forms jigs can take.

http://www.choppercompendium.com/ccforu ... f=22&t=227