Bending forces

[Hitch]

Made some tooling up today, rather than maths, i have used a bit of guess work....

Bending forces, to bend round bar, anyone know how i can work out the tonnage required? Might be one for someone with a fancy computer programme

Tooling is 100mm diam rollers, with pins through to allow them to rotate slightly, hopefully
Spaced at 400mm centres.

Top tool is a die from a tube bender, at a rough guess, 200mm radius.

Bar to bend, is 60mm solid steel, but only to 21 degrees from straight.

My rough guess is somewhere around the 10 ton mark...

 

[Welderpaul]

Any luck? problem solved?

 

[Hitch]

Yeah, bent the first 10 i need yesterday. Tooling worked a treat, barely any marks on the bar, which is a bonus.

Had a look at the gauge while doing one, mid stroke it read about 25-30 tons.

I had no doubt we had enough force, but would have been interesting to work it out.
I estimated it on square bar of a smaller size (similar csa) But i suppose the thicker you go the relationship between thickness and force increases dramatically on that sort of thing.

 

[Hitch]

The press tool and a few of the bent bars, incase anyone has the slightest bit of interest

 

[Welderpaul]

Have you had the bottom rolls in the lathe? looks like a shallow V cut into them? Hows the top tool fixed to the machine? Is the box section cruciform just there as a jig?
Looks like an upside-down bar stool!

 

[Hitch]

Top tool has a 15mm flat flat welded to it, just clamps in the machine. Rollers have been machined slighty, just to centralise the bar, and stop it making such a dent in the bar.
The box is just on there to help line it all up at the moment.

 

[Robotstar5]

That's some serious bar stools you're making!

 

[Archie]

That's some serious bar stools you're making!

They're for the American market.

 

[Robotstar5]

They're for the American market.

 

[Weldingartisan]

So the bars are part of your cable joiners? They must weigh a fair bit then, I assumed they were tubes on your other pics. Quite a challenge to bird mouth as well. W/A

 

[Hitch]

Yes, solid bar.

East to birds mouth, set up in the mill, and run a 60mm cutter through at the angle they meet the other bars.


The whole unit, weighs virtually 1 ton., one of them bar stool bits must weigh almost 200kg.