Fish mouth

[sberebit]

How does one cut the "fish mouth"? Cant angle grind it...or can you? Please let me know.

[Radical Brad]

Angle grinder.
I own only the following tools....

- inexpensive AC only welder
- hand held angle grinder
- hand held drill
- wrenches, screwdrivers, large hammer

That's it.

Brad

[TheKid]

Angle grinder, tubing notcher (Which attaches to a drill or a drill press, then you need the correct size hole saws), dremel tool, hacksaw, keyhole saw,....
If all you have is an angle grinder, use it. Just mark the fishmouth and follow the lines.

[Locutus]

Make a mockup tube out of paper or cardboard that is the same diameter as your metal tube. (Wrap the paper around your tube and tape it off, then remove from the metal tube). It is then relatively easy to use the mockup to get an exact match fishmouth by repeatedly and carefully cutting with scissors a little at a time and test fitting. Once you have the fit you want, slip the mockup back on to the metal tube you're going to fishmouth, tape it secure to the tube at the end opposite the fishmouth, then cut/grind the tube to exactly match the mockup.

[trikeman]

Download one of the free online programs and print out the pattern, then, do this:

http://vodpod.com/watch/367297-bicycle-frame-building-part-2-tube-mitering

[comreich]

In case you have a tough time finding one of the programs that Trikeman has hinted at, here's the link to Giles Pucket's app. It's the one I've been using and (assuming you can do the inch->mm conversions :)) it works really slick:
http://www.moz.geek.nz/mozbike/tubemiter.zip

[sberebit]

Gentlemen, I cannot thank you enough.
Steve

[John Lewis]

Giles Pucket's tubemitre program is great. I use it all the time. His other program sprocket is handy too. They both run fine under wine in linux so that's a plus for me.

John Lewis