gear cutter no. for ten teeth?

jmp

Cast Iron

Joined

Nov 8, 2001

Location

Mechanicsville, Va

• Aug 29, 2006

• #1

I need to cut a bunch of ten tooth gears and am not sure which cutter I need. I see that a no. 8
cutter will do down to 12 teeth but see no cutter listed for 11 or below. I sort of understand (I think) the special considerations for cutting these low tooth count gears but am wondering if off the shelf cutters exist. The gear in question is small .300 dia. I've looked through machinery's handbook about this till my head hurts. I was REALLY hoping stock drive products or boston gear would have these gears ready made but no luck there or anywhere else. Any thoughts?
Thanks,
Mike
p.s. not sure of what the pressure angle is yet.

 

johnoder

Diamond

Joined

Jul 16, 2004

Location

Houston, TX USA

• Aug 29, 2006

• #2

See if you can find Quality Rod and Gear on Google. They made me some 6 tooth stem pinions. A stem pinion has very long teeth - gears could be parted off from such a piece.

John

 

A

art_deco_machine

Guest

• Aug 29, 2006

• #3

I don't believe it is doable with a milling cutter since the root of the tooth is actually wider than at the pitch line. The shaper method is required.

 

EPAIII

Diamond

Joined

Nov 23, 2003

Location

Beaumont, TX, USA

• Aug 30, 2006

• #4

Could such a gear be hobbed? Or do you have the same problem with the undercut teeth?

 

W

wlbrown

Hot Rolled

Joined

Nov 19, 2002

Location

wright city, mo.

• Aug 30, 2006

• #5

SIR,
try this site.
http://www.grobinc.com/coldrolled/std_spur_gears.htm
they list pitches from 6 to 48, and i think yours
falls in there, at about 40?
wlbrown
wright city, mo.

 

A

art_deco_machine

Guest

• Aug 30, 2006

• #6

Yes, I got to thinking about it today, and I was wrong in saying it had to be shaped.

 

g-coder05

Titanium

Joined

Mar 5, 2006

Location

Subic Bay

• Aug 30, 2006

• #7

Your gonna need to know the pressure angle. once you have that just goto msc's site then search gear cutters. its all pretty much layed out for you.

 

jmp

Cast Iron

Joined

Nov 8, 2001

Location

Mechanicsville, Va

• Aug 30, 2006

• #8

Thanks for all the advice,links etc..! Quality rod and Grobinc may have what I need. I looked through the MSC site again but only see cutters up to no. 8. I'm guessing that gears with 11 teeth or less are outside the realm of standard cutters and require a special geometry. If pressed I may be able to squeek by with a no. 8 as this gear is in somewhat of a loosey goosey situation but I want to do it right if possible.
I'm hoping to stop by a customer of mine tomorrow and use his comparator to find the pressure angle (unless there is anther way?)
Thanks again,
Mike

 

I

implmex

Diamond

Joined

Jun 23, 2002

Location

Vancouver BC Canada

• Aug 31, 2006

• #9

Hi Mike:
Low tooth count pinions are very hard or impossible to get cutters for.
You can make your own however, and it's not very difficult to do.
You will be best off using a non-standard pressure angle unless these gears have to mate with an existing gear train, in which case you have to stick with the pressure angle of the existing gear.
I wrote a blurb on how to make/fake gear cutters in this forum: http://groups.yahoo.com/group/sherline/
Get signed in to the Yahoo group and then go trolling in the files section for it.
I think I called it "Gear cutter design 101" or something like that.
It comes with pictures that you can walk through.
If you have trouble figuring it all out, give a shout back on the forum and I'll go through it with you.
Cheers

Marcus

 

LESAWHARRIS

Cast Iron

Joined

Jan 29, 2004

Location

LAS CRUCES NM USA

• Aug 31, 2006

• #10

Mike,
how many is a bunch?
what's the face width?

eg: 10 tooth 14.5 PA 40 DP.

single tooth cutter, 3/8" shank, needs to be longer.

Cheers Les H.