Hossfeld Bender - Home Made Cam Dies?

[Pete Deal]

I got my first paying job that I need to use my Hossfeld bender for. It should be pretty simple I hope. The material is 1/8" x 3" 304 Stainless. Several bends in the easy direction. One end gets a few tight 90 degree bends and the other end gets a 180 degree bend with a 4" radius. These are hooks to support a hose.

I think I need to make a cam die (tear drop shaped die) for the radius. Anybody got an easy way to make these? I doubt the forces will be very great in this application so how about stacked plywood? Second thought would be to plasma cut some plates and stack them, maybe with washers between to space them apart. Not sure what the spring back will be like so may have to make a few tries to get it right.

 

[Rob F.]

I dont think you need to make a cam die for that. I would bend the tight radius bends first and then use a stop of some sort to hook those bends around and bend the large radius around a 3" pipe. You can either weld in a few washers to center it on the 1" pin, the material will spring back to around 4" radius, but you will need to test bend to be sure.

 

[Pete Deal]

For some dumb reason I wasn't thinking pipe. Good suggestion. I'll start with 3" pipe and go from there.

 

[memphisjed]

Start with your inner radius die 1/1.027 x finished inner radius. I have found since I have access to burn table that pipe sometimes should but never works as well as solid (laminated plate to thickness).

 

[metalmagpie]

Start with your inner radius die 1/1.027 x finished inner radius. I have found since I have access to burn table that pipe sometimes should but never works as well as solid (laminated plate to thickness).

Bending over a die 1/1.027 smaller than desired radius is an effort to compensate for springback? Is that constant related to the OP's material being stainless, or being 1/8x3" flat stock the easy way, or is it just a rule of thumb? How accurate is it?

 

[memphisjed]

Bending over a die 1/1.027 smaller than desired radius is an effort to compensate for springback? Is that constant related to the OP's material being stainless, or being 1/8x3" flat stock the easy way, or is it just a rule of thumb? How accurate is it?

Rule of thumb for cold bending any cross section- it changes with really tight or really big, big you start getting into memory instead of spring. I guess kinda of the same but not. Small you start getting into what we called “setting” in the blacksmith shops. Not sure if that is technical/proper term.

It is almost scarey accurate 7 out of 10 times. The other times the die is to big, easy fix with flap wheels and your dewalt portable shaper.

 

[dana gear]

Every Hossfeld I have ever seen, including ours has a bunch of custom dies/fixtures made for it, truly a very versatile tool.