I have a JD2 #3 bender, bending 1" 0.065 4130 on a 3" radius, and every other bend flattens out on a 90* bend. it starts to flatten out at about 80*

I'm assuming its simply due to the density of the material & the fact that it is so thin, there is no room for it to stretch so much on a 3" radius 90* bend.

Am i correct in thinking this?

I am not a newbie to this, just saying i know how to use the bender.

Thanks guys

 

I use a hossfeld bender and can bend around a 2 1/2 radius die usually. Do you use oil on the dies. You should oil the follow die which is the one that does the bending. That will put less stress on the outer radius material while bending.
Also make sure that the tubing doesn't slip in the clamping . If it slips it will also tend to kink or flatten

the bender you have works the same and is basically a copy of the hossfeld

 

I see your point. I do use alot of oil on all the parts...

i will try again

 

Well I figured it out, was pretty dumb. Key thing to remember... CRANK down on that bolt that holds the tubing!!

 

if you read my post it says that you need to check the clamping and the tubing can't slip

good luck

bob