Inexpensive tubing bender?

[purplepickup]

Every so often I come up with an idea for a doodad that requires that I bend some tubing, more often than not, emt conduit.  Is there a cheap way to make nice bends in tubing...say down to 1 or 2 inch radius in 3/4" od tubing?

[kb426]

I'm not aware of that small of radius. I think most of my stuff is at least 3.5. As far as cheap, I'm no help there. I've seen people use a piece of pipe with a plate welded on either side but I've not seen the results with small dia. tube.

[wayne petty]

have lathe and mill.. will create..


something like this.

http://www.grainger.com/product/BRAMLEY-Tube-Bender-49U756?s_pp=false


frozen water in tube..  or ends installed and packed tight with sand..

http://www.grainger.com/category/tubing-benders/plumbing-tools/hand-tools/ecatalog/N-97h?bc=y#nav=%2Fcategory%2Ftubing-benders%2Fplumbing-tools%2Fhand-tools%2Fecatalog%2FN-97hZ1z0n2r5%3F_%3D1393367264523

make a pair of these..

http://www.grainger.com/product/FEIN-Tube-Die-Set-21VK25?s_pp=false

or some rollers with flanges.. to allow a pair of rollers to interlock.. feeding thru a guide tube..  and a third roller on an eccentric to rotate it into the path of the pair of rollers..  a rack and pinion to allow an easy push..with  assist..

if you make the guide blocks openable.. you could actually have an L shaped push lever.. with a hole.. so you could fasten a mandrel tool on a long rod at the bend inside the tube.  this could be used with several sizes.

one could make guide blocks out of wood with a router.. which would reduce cost significantly..  a mustang 2 rack as its easy to mount.. a notched or drilled bar mounted above and on both ends allows you to change the push point quickly..  
push lever that grabs onto notches\ and resets when you rotate wheel
|---=----=----=----=----=----=----=---|
pinto rack and pinon

man.. i need a lathe and a mill..

after all this work.. it might be ashame to use EMT..

one of my other ideas is to use  hydroforming to make expanded sections in roll cage tubing  like a bendy straw... this is installed outside the cage where it attaches to the frame. and also sections in the frame in front and behind the cage.. a properly selected tube section welded inside this  collapsible section at one end only.. these entire assemblies are installed

they allow the sections to CRUSH in an impact.. reducing the G forces on the driver in accidents.. and reducing damage to the central cage structure..

i recall learning not to straight arm but keep the elbow bent when running..  to reduce breakage.. theory stands for race cars also..

imagine .. crumple sections in nascar cup racing..

sorry to get off thread..

[purplepickup]

I didn't do a real good search before I posted.  I see the small Woodward and knockoffs in my price range.  I hadn't checked HF either and see they've got a couple.  I don't need precision, just dies and a way to make them form a bend without kinking.  I can live with larger radii.

[kb426]

I bought the Speedway version which is the same as the Woodward. I'd have to go dig it out to check for sure but I don't believe it will go down that tight. I have a H.F. version that is similar to a Howron No.2. The smallest dies listed are 4" radius. Also, The Woodward/Speedway versions work from the same principles as a Hossfeld. It's work to use it with any wall thickness above .035 in steel.

[416Ford]

We have a Hossfeld Bender at work that will do as little as a 3/4" IS radius if that is the pin size you use. I have an old one in my garage with no dies so it will only bend around the pin till I make dies.
You could always make a die out of wood for that diameter pipe/OD tube. then two pins on a bench.

[wayne petty]

i ran across this info on tube bending..

there are MULTIPLE pages there...


http://toolsforbending.com/tooling/corrections-for-poorly-bent-tubes/

[purplepickup]

That's some handy info Wayne....if I get something I can adjust all those things on.  Thanks.

416Ford, I've been bending with a pulley mounted on the bench and pulling against a pin in a hole on the bench but it's clunky with mixed results.  I'd like to have a little more control of things.  The project I have in mind right now is mounts for pannier bags or cases for my 'WTSHTF' bike.  Just kidding....it's a dual sport bike that I'm taking to the Arkansas Ozarks in April and I might need to carry some stuff.  I want them to look decent and fit well enough to easily take on and off.

[416Ford]

I would say your more then welcome to use my Hossfeld if you want to pick it up with a truck. It just sitting in my barn doing NOTHING.

[kb426]

George, are you copying the Givi style mounts? That's what I use. There's some cheap stuff out there that are knockoffs. I've been real pleased with mine. I bought my first one almost 14 years ago. Still going.

[Crosley.In.AZ]

I've got a tube bender, for 1/2 inch round tube or solid...  I'd have to post photo of it.  Dont even rmember the brand.

It would be very nice to bend tube for the mount stuff yur talking of   .....  George.  

I built shifter mount and other items in my Falcon & Simca with 1/2 inch tube, 063 wall steel

[chimp koose]

Saw a show on tv once where they were making trumpets and the tube was bent by filling it with water and freezing it.

[purplepickup]

George, are you copying the Givi style mounts?

Yes,sort of.  I'm thinking about the bottom mount replacing the flip up part of the passenger footpeg and the top attaching to a rack I already have. Easily removed.  Any I've seen for my bikes are sort of pricey and would need to be modified to my liking anyway so making my own seems to make sense.

For a bender I'm thinking about just using a couple of sheaves as roller dies mounted so that I pull one around the other with the tubing between.  Still thinking though.

[GPster]

I have enough trouble getting anything done to think about tools for doing more. Back when I was still able to work (ancient history) and working in a plant with a lot of high pressure steam I noticed a lot of tight radius weld ells. I thought if you got a weld ell for pipe that's inside diameter was slightly larger than the outside diameter of what you wanted to bend you would be able to cut the weld ell in such a way  to make a form for the inside radius of the bend to keep from crushing the smaller pipe for bending. The outside radius of the weld ell could be pieced to make the outside forms. If you had a press and you weren't trying to build a set of roll bars you could probably just buy one weld ell sized for your tubing and play with  your bends this way. GPster

[enjenjo]

Another thing to mention, EMT is not a very good quality steel. You might have more success using a better quality tubing. As I recall there is a Alro Steel store near you that might be able to help you out.