Tube roller question????

[Goldhunter_2]

I'm getting ready to start a new project and instead of hand bend conduct this time I am going to spend a little more money on aluminum tube. The Oval aluminum tube is what I want, but they don't make a thinner wall or smaller size plus I still have to roll/bend it. I am looking at buying either a manual tube roller with round & square dies form HF or I found a used "antique" power square 1" tube roller I think I can try to get reasonable but I want to roll oval shapes but material will be either the bigger thicker store bought & shaped tube (1.5"x3/4"x0.125) or smaller thinner wall round tube rolled myself. No one seems to really sell oval roller dies only square or round for the manual tube roller. I would probably definitely have to make my own replacement dies for the antique one if I wanted any other size then the 1" square it has.

( I have a like for antique machines so I would rather try to buy that one even though it takes up more space but I need it for to do a certain thing to meet my needs, so I need to know if my line of thinking is correct before I buy it)


Questions:

1) If I put 1" and/or 1/2" round thin wall steel dom tube,conduct,aluminum tube into either a 1" square roller die or a 1.5" round die would it just roll it and remain round or would it change to a uniform oval shape?

2) If the first question will not work how do I reshape a whole stick of 1" round tube into a 1" oval tube?



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[Ark1]

Basicly the shape you want is the die you will require.

You may get lucky by squeezing a round section of stock in a square die, but the problem will be where is the weld in the tube and the bend or squeeze rate will change and leave less than a uniform shape.

You will have to make dies and if the change is too radical to do in one step you may need 2 or more sets to gradually form the shape you require.

This is what I call seat of your pants engineering, trial and error will in time lead you to what you want to obtain.

Ark1.

[Goldhunter_2]

ok thank you , that is what i was afraid of I guess I'll plan on making dies

this is the shape I am looking for in about 1 1/4"x1/2"x.090 it shouldn't be to hard to make the die itself just finding the stock to start form may be difficult

[Ark1]

If you want the flat to be uniform.

You may also have to sand pack the tube as this is considered post forming.

When round tube or square tube is made it is shaped first then welded.

By squeezing the round tube in the middle you may just end up with the outline of a figure 8. The sand would prevent the crush in the middle.

Ark1.

[Goldhunter_2]

would I pack it tight or half full of sand ?

[Goldhunter_2]

would I pack it tight or half full of sand to do this?

[Ark1]

This is where it gets a bit tricky. You must consider the change in volume of the pipe. If you go from one extreme a round pipe to a flatened pipe there will be no volume for the sand. However in this case the change in inner volume may not be all that much.

When I have done small one off's like this I will make a plug and weld it to the end of the pipe then fill with sand. The other end turn a hardwood plug and ram it into the pipe a few inches from the end.

When you are rolling the pipe to change the form or shape the process is normally a back and forth process. Roll toward the wood plug, then back add more pressure and repeat. The sand will form a wave and push back a bit on the wooden plug, it has give. When complete cut off the welded end of the pipe and assuming that it is a straight lenght pour out the sand and use a rod or length of pipe to drive out the plug. You could bore the plug and instert a bolt through it with an eye and a short lenght of chain to use a slide hammer to remove the wooden plug.

You can try forming without the sand, but if a colapse occures follow the sand pack directions.

Ark1.

[Goldhunter_2]

ok thank you