Bending T section..

[KemppiFrog]

Hi all,
I have an order for an arbour. Nothing fancy, just three frames in line with some solid and some wire between them.
Tops are curved T section as normal here and I was concerned that I might have to make up some grooved rollers for my roll bender. T is bent with the lower leg on top, so stretched.
Anyway, just to check, I bunged a bit of T through the bender, half expecting it to come out crippled and twisted. But not, a fair curve and straight.
VERY pleased. Making the two grooved rollers would likely take about four hours, about the time it takes to make the whole job..
KF

 

[stuvy]

Would a relief cut help to stop the twist?

 

[KemppiFrog]

Would a relief cut help to stop the twist?

Not sure I follow you?
The flat of the T was under the middle roller while the lower leg was supported by the two driven ones. It came out nicely curved and in line. Plenty good enough for the job.

 

[Morrisman]

Interesting, as I would have expected carnage too.

I once tried to curve some Z profile steel bar for an arched window frame. Hopeless, chaos, tried with heat and clamps and leverage, no chance.

I gave up and cheated eventually......

 

[Lazurus]

Not sure I follow you?
The flat of the T was under the middle roller while the lower leg was supported by the two driven ones. It came out nicely curved and in line. Plenty good enough for the job.

Which roll bender do you use?

 

[KemppiFrog]

Which roll bender do you use?

Home grown, usually does 40x40 tube for gates, or even 50x50. I will put a pic up later.

 

[KemppiFrog]

Interesting, as I would have expected carnage too.

I once tried to curve some Z profile steel bar for an arched window frame. Hopeless, chaos, tried with heat and clamps and leverage, no chance.

I gave up and cheated eventually......

View attachment 177500

Dat's nice
No surprise that Z section was a pain, I have just fabbed it up in the past.

 

[Hitch]

Because the leg is central, you put even pressure on with the rolls, if its a decent radius it wont go far.

If you were going the other way with the tee, youd likely have problems. Channels and angles are much harder are more of a pain o roll 'toes in' too.

 

[stuvy]

Sorry @KemppiFrog i thought you’d bent it the other way round

 

[Mick Annick]

Would love to see your roller too - I’d like to make up an arbour too

 

[Screwdriver]

If the leg of the T is the outside radius, you could start off the curve by simply peening it. You could also finish off the straight ends you'll get from the roller.

 

[KemppiFrog]

If the leg of the T is the outside radius, you could start off the curve by simply peening it. You could also finish off the straight ends you'll get from the roller.

That would be quite a lot of peening as there are three at 2 mt each..
As it turns out, I did them today and there was a bit of twist, which I fettled out in the vice.

Here it is, originally hand turned, it sort of grew by stages. One of these days I will take it to bits and tidy it up. That is a 2HP motor bolted to a 40/1 reduction.
KF

Edit: Test bit on the right, but too tight a radius.