The Chopper Compendium

My son and I are building a tube bender to facilitate an SCCA cage fab. We will be using JD2 M32 dies for this project. We need the hole location dimensions for the back block pivots in the main frame which are 1 1/4 inch diameter. This bender is an upgrade to the CBH design to use the Model32 dies.

any help would be appreciated.
MarkD

Here is what we are working on.

what exactly do you need?

Thank you for your reply. I need the position of the 1 1/4" diameter holes in relation to the main pivot hole.
1) distance that the holes are offset
2) distance down to the first hole
3) distance down to the last hole

Your help is greatly appreciated

This should be what you need?

The offset should be able to be calculated knowing the holes sizes?

If you could can you please make your bender prints available here for others?
And we would love to see build pictures of the bender?



Holes in the arm Distance of holes 1.25 offset.
hole
1-2 = 1.45in
2-3 = 1.45in
3-4 = 1.50 in
4-5 = 1.50in
5-6 = 1.50in
6-7 = 1.50in




Total length of holes along the arm= 7.400



Measured the arc of the circle off the pivot hole to first hole in arm and measured = 3.950



Measured to the edge of the arm to the edges of the holes .
To the arm holes from edge add half the hole size to this. .625



Subtract half the hole size from this. Add the 2 together you will have the off set. With the radius of arc measurement should be able to do trig to get it offset the other way.



You need it measured any other way just ask.

I have dies also.

Thank You

Using what you gave me this is what I have.

There is 7 position holes in the arm your print only has 6?

I double checked it the print looks right?

You want i can do out side to out side measurements moving the pins around?

5.20 - 1.25 = 3.95

????

The offset must be off in the print causing the .020 difference?

Could you please measure over the last hole and the pivot pin.

Thanks again

This has to be what it is.



direct link to image

http://i.imgur.com/AtLFe4gl.png

if you need the cad file i can get a link for you?

Perfect thank you again.
I hope to send the files out tomorrow.

We would love to see your bender built and in that thread you could document your car build if you would like?

It would be nice to have your files on this so we could help others in the future with them if you could be so kind?

once I have proved out the drawings and bender function I will gladly share the files and do a build thread.