Tube Coping Calculator- a very easy "fishmouth" tool.

#1
I stumbled on to this handy tube coping calculator posted and modified by "Metal Geek."

By entering tube OD, wall thickness, adjoining tube diameter, and the desired angle of offset, the program will compute a perfect geometrical shape you can use as a pattern for cutting the coping. You then select which format you want it to come out in. I used .PDF, and the size/ratio was perfect right out of the printer.

Here is what mine looked like with two 1" OD pieces, wall thickness of .115 set at 90 degrees.



The top line is the guide for setting the template on the zero degree mark. In my case, I leveled the bike frame, then lightly painted the rear area where I was installing the 90 degree tubing for my axles. I then took a metal straight edge and scored both pieces at the level. This gave me my zero degree mark.

After that, I simply aligned the marks, taped the thing together around the tube and spray painted again, to illustrate the area for cutting. Then a quick pass with my angle grinder and I was done. It took a matter of minutes to get a tight fit. I have spent a lot of time in the past getting perfect angles down, and this was so incredibly simple in comparison.

I know some of you have tube notchers. You might be surprised how easy this is in comparison.
 
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