Single point gear cutting

[jguillen08]

Hello all,

I am researching gear cutting, and I am thinking about doing it my self. I am woundering who out there had done it the single point method. Any tips of how to grind the tool? How successful is this method.

Thanks,
Jose.

[fkaCarel]

Normally you use gear cutters, they come in sets of 8. The method gives "approaching" gears, they are noisy above a low (lowish) rpm. This method is inferior to the evolving milling method used in the making of industrial gears. I made several times a gear without a gear cutter, just by grinding the bit till it fitted in the tooth. Perfect? No. Every imperfection disturbs constant velocity and it will never wear in. But for low rpm replacements, why not?

Carel

[Mcgyver]

Jose,

while not a form cutter, here's an idea for a home made cutter to for gears. Peter Harrison's site gives a very good description of what I call faceted hobbing. Its not really hobbing but it is a very cool way to make your gears and cutters without requiring true hobs, a swiveling mill table etc., or form cutters As this needs is a lot of back and forth stuff/index repetition. As Carel said, form commercial form cutters are also only an approximation - so lacking gear generation equipment, this might be as good as form cutting? haven't had a need to cut a gear since i saw this, but it looks to be worth a try

http://homepage.ntlworld.com/peter_...tting/index.htm

[Heavy D]

link does not work

[Heavy D]

This one does though....

http://homepage.ntlworld.com/peter_...tting/index.htm

[Geof]

The cutter is a whole lot of single points and the gear is a worm gear but I though I would show that you don't always have to use conventional equipment to do something. This is a converted benchtop lathe and to date it has generated about 400, 4" diameter 60 tooth wormgears from a 1-1/8" -6 acme tap.

[sanddrag]

Wow, that link is pretty interesting. Looks considerably difficult to make the cutter though. I think I'd just buy an involute gear cutter (McMaster page 2395 toward the bottom).

[JRoque]

Jose, do you have a CNC mill? Though limited in how small a gear I can cut, I've done several using Rhino+free plugin and cut with regular endmills. I'm also limited in the types of gears I can cut (ie: not worm) but that should be solved with a 4th axis indexer.

JR

[jguillen08]

Just a thought, but has any body ever heard of a carbide insert that has a true involute shape. I think it would the way to go for making gears the single cutter method.

[fkaCarel]

If you want to make a range of gears between 15 and 136(rack) you would need 136-15 = 121 cutters, that have a true convolute shape. Because this is a little bit over the edge, they divided this over 8 ranges. Take a look at a gear hobber and try to figure out, how these machines make with 1 mill per modula, perfect gears. Try to figure out the difference between the mill in the link (incorrect) and Geof's hobber mill (correct). Hint: Every tooth is corrected off-center. After that you will see the unavoidable imperfection of the gear cutter.

Carel

[GAWnCA]

Originally Posted by sanddrag Wow, that link is pretty interesting. Looks considerably difficult to make the cutter though. I think I'd just buy an involute gear cutter (McMaster page 2395 toward the bottom).

Sanddrag,

Does McMaster have a web site?

[sanddrag]

Originally Posted by GAWnCA Sanddrag, Does McMaster have a web site?

By all means yes

Google is wonderful thing.

With the exception of food, there are very few things I've found that McMaster does not sell. That place is wonderful. They are one of the largest industrial suppliers around.