Hiya guys.

Just wanted some opinions on the best way to cut fish mouths? Any bright sparks dreampt up and easy way?

Try TUBEMITER. Works perfectly.

ATB Dan.

i tried a holesaw in a pillar drill and its hard work even if doing 90 degs. Never used the tubemitre prog but people do say it works well. Definately an effective cheap solution.

2nd for tubemitre, superb bit of software.

Cheers

Rich

One way of doing it, though a bit more labour intensive!
Basically get an old bog roll and cut up one edge. Then wrap it around the piece of steel you want to fishmouth and gaffer/masking tape it so it's the right diameter.
Then you hold it against where the component has to fit and using a pair of scissors hack away until you have the right profile.
This is then slipped over the tube to be cut, the profile transferred with a marker pen and the tube attacked with an angle grinder!
Probably not as pretty as the other options but it works

Holesaw is the easy way.
http://www.mechwerks.com/Coping.htm





[Edited on 8-5-10 by mangogrooveworkshop]

holesaw is good if you have a regular fishmouth to cut but i use a flap disc to extend the mouth if i need a "long" angled fishmouth, it takes a little practice but i do all the wishbone cross braces that i make this way, ( and i,ve made a few )
basically I use a jig , cut the tube over long & keep "fettling" until the tube fits perfectly in the wishbone jig.

cheers
andy

The last fishmouths I did were the ones between the main roll hoop and the front facing braces on a mid engined chassis.
Dissimilar tube sizes, compound mitre angle.
I'm afraid it was a case of edging up to a good fit via a marker pen and an angle grinder.
Hole saw works well for single angles or 90 degree cuts though.

I have a medford tools notcher which is great.
http://www.youtube.com/watch?v=QnubbAFVObQ
For complicated or difficult stuff I jig and fettle

I will have a tube notcher for sale very soon... (if you're interested!)

I can tell you how many times it's been used if you need to know!!! (OR YOU CAN COUNT YOURSELF! )