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View Full Version : How to make tube into an oval

ztec
08-17-2004, 08:29 PM
I was just curious how people do this by hand. For example on a bike frame were a 2 inch tube is shaped like a oval at the end in order to be noteched onto a 1 inch tube.

HWooldridge
08-17-2004, 10:08 PM
You can mash it in a large radius swage, i.e., a piece of 1" OD tube gets placed between two 1.5" radius curves, which will make it into a gentle ellipse...or just use a soft hammer and go slowly.

ztec
08-18-2004, 07:21 PM
I know what a swage is but Im not sure I understand how to do it your way. Could you explain more....thanks

HWooldridge
08-19-2004, 10:00 AM
This is an example only - you may need to think about the radii for your project: Take a piece of 3" pipe about 4" long and cut it in half lengthwise. At this point, you have two pieces that if put back together, would be 3" inside diameter. Picture in your mind cutting away a third or so of each piece (lengthwise again). Now, you have two pieces that are still radiused to 3" but if put together, would be an oval and the widest distance between about 2". If you weld a piece of angle iron across the bottom end of each piece of pipe, you can put the pair in a bench vise and squeeze the end of a piece of tubing into an oval. For your project, determine how much oval you want in the tubing and draw it on your welding table, then adjust the width of the "swages" so they meet properly. 3" pipe may not give you the look you want so it's easier to do the calculating on paper before cutting steel. I hope this makes sense.

ztec
08-19-2004, 03:54 PM
ok now I get it....thats a good idea, thanks