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George Seal
04-30-2006, 12:42 PM
I need three gears 20 DP 14 1/2 PA
two 90 tooth and one 22 tooth.
Question???? do I need two cutters or will one work for not so perfect gears
cutter #5 = 21 - 25
cutter # 2 = 55 - 134

If one will work which one
these are fairly low speed gears

torker
04-30-2006, 01:34 PM
Kinda scared to admit it here but I've done it. I'd use the #2 cutter.
You can't use the proper spacing for the gears that is called for though. You have to use a little "windage" on them or they bind up or are too loose.
We'd all think nothing if driving something with a sloppy old chain and sprockets so why not a bit off a loose fitting gear on an application like this?
Russ

George Seal
04-30-2006, 01:43 PM
Thanks Russ,
sort of what I was thinking

John Stevenson
04-30-2006, 04:05 PM
George,
What Russ says, at 20 DP there isn't a lot of difference as regards interferance.

http://homepage.ntlworld.com/stevenson.engineers/lsteve/files/20_90gear.jpg

Shows them geometrically drawn.
The red gear is your 22 tooth cut to the correct depth of 0.108"
The white gear is a correct 90 t also cut to 0.108" with a No. 2 cutter.

The blue gear [ bottom ] is a 90 T cut with the No 5 cutter also to correct depth of 0.108". Note the sight interference if you can between the blue and red teeth.

The Black gear [ top ] is the same No 5 cutter gear but this time cut to 0.113" deep and this has just the right amount of clearance.

.

George Seal
04-30-2006, 09:57 PM
Sir John,
Once again clear as mud ( not unusal for me)

one cutter #5

22t cut to depth of .108

90T cut to depth of .113

Thanks for the reply