I'm using Ivan Law's book to design / cut some bevel gears usig the
"Parallel Depth Method". An errors or omissions in his text? Seems OK,
but not done this before and I'd rather find mistakes on paper rather than
on the machine!
I'm planning to cut two gear sets, one 26:14 and one 14:13 both 45deg
bevel. (I've picked odd numbers because someone told me it's good practice
not to have the same teeth coming into mesh all the time).
Can't help with any errors in Ivan Law's book but the concept of the
odd teeth numbers is called a hunting tooth. The idea being that
periodically every tooth sees every tooth on the other gear so that
errors in the profile aren't accentuated as could happen if the same set
of teeth always meshed. I have seen it said that with modern production
techniques with higher accuracy it is less necessary though.
Steve, have a look at: Subject title: in the
rec.crafts.metalworking archives for 11 Nov 1007, by Stealth Pilot.
You may find some hints for your bevel gears even tho' the article is
about spur gears.
Mike in BC
I have cut bevel gears using Ivan Law's book (No17 in the Workshop practice
series)and they work fine. Used the method for the differential on my Foden
lorry at 3" scale last time round which is the largest I have cut.