Flattening a round tube, HELP!!

[Jeff May]

Hey all,
I have some 3/4" DOM tubing that I need to put flat ends on in order to bolt the tube to a tab.
I tried just putting it in my press, worked ok. Was not like what I have that I need to replace.
I have some pics attached so you can see what I need to do.
I'm assuming there is a die of sorts used to do this.
Can anyone offer some suggestions? How about you guys that build your own tube chassis?

 

[zkdiesel]

Press, heat and sledge hammer will get you close but not pretty end result

 

[Jeff May]

Usually, maybe, but this is for a restoration on an old racing kart. Want to keep it like the factory did, or at least try to.
Thanks....

 

[A_Pmech]

Getting the tube to collapse symmetrically is a challenge. I'm sure some of the bicycle builders here probably have an elegant way to do it.

 

[pi_guy]

Material supply houses use a die.
http://www.aedmotorsport.com/blog/a...ipment-to-produce-custom-aero-tube-streamline

 

[IlliniJeeper]

To get it to look like that, you're going to have to do it in a press and construct a die with a pinned pillow section to hold the tube you don't want crushed while you drive home the flat portion evenly. It won't be cheap or easy to do and you may be better off finding somebody with the tooling to do it for you.

 

[dadsEH]

Heat and a BFH should do the trick.

 

[zkling]

You need a FT&P press die (flatten trim and pierce). Somewhere in my mountain of press tooling I made one for 1" DOM. Essentially it is like a press brake that uses 2 highly polished dies that look like body dollies. The entrance edge geometry will dictate the transition point from full diameter to flattened.

 

[rsanter]

That original one was done in a press
You need to play with some tubing to see what you need to get it done but I'm seeing a fixture that aligns on the tube and then has a round anvil in the area that gets flattened

Bob

 

[over40pirate]

In 1970, I had a friend who was an amazing machinist, fab a springer front end for me, that I designed.
He machined 4 dies (2 different sized tubes) and pressed the ends in them. Beautiful and strong.
He was a guy that do jobs that other machinists said they couldn't do.

 

[BFBOB]

I'd try making dies from cylindrical sections of a diameter to match the radius in the transition from flat to round on your sample. Drill the holes that will be in the finished piece, drill matching holes in the dies. Thread the stack together with a grade 8 bolt shank, or drill rod, and apply pressure, BFH, and/or heat as needed. And then report back with pictures!!
I've only tried to do this with hammer on concrete. Not pretty.