Welding Tips and Tricks

Long shot on this forum but this is for anyone who has experience fabricating using thin wall tubing (0.035" wall) with small tubing size (0.375" OD). I'm making flags for the film industry from this material. They are 48" long and 5.75" wide outside-to-outside, rectangular. They are held in stands by a rod that extends from one end. As these frames are rectangular, they have 4 (four) 90 degree bends. These bends reduce the overall amount of tubing required for one frame. But how do I calculate the total tubing length so that I can cut before I start bending? 48" x 2 = 96" and 5.75" x 2 = 11.5" for a total of 107.5". BUT: this is not the total length of tubing required. It's LESS than that because the four 90 degree bends reduce the total. What's the formula? How do I work this out. Thanks in advance from a novice taking his first steps in tubing bending and fabrication...

The easiest way is to calculate lengths based upon the centerline of the tubing. Then add/subtract for the tubing diameter.

There are reasonably priced software packages available for calculating bending tubes of many shapes. It will provide you exact lengths based upon material, bend radius, and spring back. I use Bend Tech and have had very good results.

cj737 - There you are again! I looked up Bend Tech. Had no idea they existed but they seem highly competent. I'm in touch with them on their software so I can get the right package. Thanks again for what you're doing out there for us new guys...

i would also make some cheaters up. ie bend up some corners and have all the locations marked on them for where it fits in the bending tools, so you know how much length to leave on the pipe, starting position etc.
it also helps as a sanity checker when bending, something to compare to.

Good idea. Did some of that already but burned through a bit too much tubing... All good though. But I agree, nothing like finding out for yourself.

tweake wrote: ↑Mon Jun 03, 2024 10:14 pm i would also make some cheaters up. ie bend up some corners and have all the locations marked on them for where it fits in the bending tools, so you know how much length to leave on the pipe, starting position etc.
it also helps as a sanity checker when bending, something to compare to.

The software I use calculates those extensions, Tweake. It provides exact lengths for feed and out feed through the bender. Virtually dead on and no waste once you get the spring back dialed in.