Ideas for bending some 25 SHS

[SurfinNev]

I have three braces to make for a fibreglass canopy to install inside for roof braces. These will have legs welded to ends to act as a roof support and for attaching a ceiling panel. They are 25 X 25 x 2.5 SHS,1430mm in length and need two bends as shown in the attached drawing. They need to be bent so both ends are 35mm from the straight centre section. Any simple ideas on how I can do this without a proper bender?

Nev

[Clubman7]

If your welding the ends to something, can't you cut notches out where you want the bends without cutting through, and then bend them to the angle you want and weld up the joins where it will meet.
Will tend to crush the tube doing it otherwise.

[Stustoys]

Hi Nev,

I'm about to run out so I haven't worked out how wide the gap would be but at first look I think I'd cut through the top and sides with a hacksaw, bend to the angle you want and MIG weld up the gap.(assuming if there is any real load it will be from the left?)
I dont

Stuart

[SurfinNev]

Thanks guys. Did do an experimental with some thinner walled SHS to get an idea how much to bend by cutting with a grinder and 3mm cutting disc. This produced a gap that was too wide. A hacksaw width is too small a gap. Would rather not have to cut and reweld if I can avoid it. Some deformation, as long as it is uniform, is not a wory if I bend it, as it will be covered by a ceiling panel. This is for a ute canopy that I am converting to a camper for my brother. I want to put some form of insulation in the ceiling so these braces act as a support for the fibreglass top as well as attachment points for the ceiling panels and a gap for the insulation. There's no real load on it at all and the braces are mainly for getting a level surface for the ceiling and to prop up the middle section of the canopy top which has a slight sag to it. The legs at the ends will sit on the aluminium frame inside the canopy and will easly support the small amount of load on them. These will be attached with bolts through the canopy top sides to hold in position.

Nev.

[th62]

That size will bend relatively easy without crimping: Mark on the stock the start and finish of the bend, place one end in the vice (horizontally) with the start mark lined up with the end of the vice jaws, then slide a larger tube or pipe (overtube) over the 25x25 (the end of the overtube on the finish line) and pull it around. The angle you intend bending is minor and should bend in a reasonably tight arc. Instead of welding legs on you can do the same there. The overtube will keep the sections between bends nice and straight. If the stock twists, untwist with a very large shifter. Try on a short piece about 300mm first, the end of the over tube only needs to be an inch or so from the vice for the minor bends, further for the leg bends. You can fill with sand if you like, but it's not really necessary for smaller bends like this. The rounder the shoulders are on the stock the better it will bend. You can also make a jig as per the pic. I have a number of these in different diameters.

[Michael G]

Do you know anyone with one of those hydraulic pipe bender things? With care that would do it. The other one I've heard of is to put the RHS on a couple of packers and lower a heavy weight onto the spot you want the bend.

Michael

[simonl]

Hi Nev,

no doubt you have seen some of the youtube videos showing the bending of SHS tube.
Hand bending 1" square 18 gauge steel tubing to a 4-1/2" radius - YouTube (http://www.youtube.com/watch?v=bjRlA4HxuyQ)
https://www.youtube.com/watch?v=vguWbHxzG98
Looks pretty easy to do something like these although the second one looks a bit dodgy, designed for single use.

Cheers,

Simon

[SurfinNev]

Got those roof braces bent, the legs welded on, all drilled with nutserts in legs to attach to side of roof. Look pretty done in SA5 Zinc plating. Trial fitted and happy with it so far.

Nev.