• We want to encourage those of you who ENJOY our site and find it USEFUL to DONATE and UPGRADE your membership from active member to donating or premium membership. If you want to know the differences in membership benefits, please visit THIS PAGE:

    https://www.hobby-machinist.com/premium/

    Donating memberships start at just $10 per year. These memberships are in fact donations that help pay our costs, and keep our site running!
    Thank you for your donation, God Bless You
  • June Project of the Month (Click "x" at right to dismiss)
[4]

Making gears.

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

Hukshawn

Titanium
Former Member
Joined
Nov 19, 2016
Messages
1,400
Likes
1,010
#1
At some point I’ll be making some gears to use in an x axis power feed, or a knee feed, or whatever purpose I find that I need gears. I have no set pitch, or diameter, or tooth count. Is there a general gear cutter that most people turn to for general use? I realize it’s allllllll specific to the size and number of teeth, but, I’m starting from nothing and nowhere. Is this something that can be answered even befor I’ve ironed out details?
 

ThunderDog

Active Member
Active Member
Joined
Dec 12, 2014
Messages
210
Likes
298
#2
I consider myself a newbie in the world of machining, however gears need to match or they will destroy each other due to a mismatch in proper sizing. From my limited exposure to different machine tools, 20 DP 14.5 PA seems somewhat common for older machine tools. That size will produce some rather large gears if space is a concern. I'll let someone else chime in if I'm wrong about any of the above info.
If you want a crash course on sizing I made this video not too long ago:
 

Bill Gruby

Iron
Former Member
Joined
Jul 13, 2012
Messages
0
Likes
10
#3
That is a great video. Followed to the letter you can't go wrong.

"Billy G"
 

Hukshawn

Titanium
Former Member
Joined
Nov 19, 2016
Messages
1,400
Likes
1,010
#4
Nice video. I learned.
So I'd need two gear cutters if I wanted to cut two different sized gears, depending on their size.

I have some pondering to do. I need to make a bevel gear to turn 90 degrees for a knee feed motor.

I have some thinking to do...
And I need a proper machinists handbook. My wife got me a smaller book last year but it's the wrong one. It's industrial and has nothing to do with gears.
 

ThunderDog

Active Member
Active Member
Joined
Dec 12, 2014
Messages
210
Likes
298
#5
Bevel gears...something on my need to learn list, too.:eagerness:
I believe youtuber, Myfordboy has a video of cutting bevel gears.

Machinery's Handbook is definitely a good thing to have. Mine is quite old and has everything I need. Don't feel like you have to buy the newest one, that's my .02 cents of advice.
 

Bob Korves

H-M Supporter - Sustaining Member
H-M Supporter - Sustaining Member
Joined
Jul 2, 2014
Messages
5,193
Likes
5,556
#6
This is a good book:
Gears and Gear Cutting
by Ivan Law
ISBN 978-185242-911-2
It is written for home shop machinists. New price starts under $10 if you shop around, used even cheaper.
Edit: See post #8. The book is available here on this site!
 
Last edited:

benmychree

John York
H-M Supporter-Premium Member
Joined
Jun 7, 2013
Messages
2,045
Likes
1,514
#9
Nice video. I learned.
So I'd need two gear cutters if I wanted to cut two different sized gears, depending on their size.

I have some pondering to do. I need to make a bevel gear to turn 90 degrees for a knee feed motor.

I have some thinking to do...
And I need a proper machinists handbook. My wife got me a smaller book last year but it's the wrong one. It's industrial and has nothing to do with gears.
Bevel gears are not easy to cut, it takes a special cutter, made for bevel gears and not commonly available, and also it takes three cuts at minimum for each tooth; the cutter makes the small (inner) end of the tooth space, then the cut is offset and the tooth rolled and another cut taken on each side of the tooth space to size the outer (big) end of the tooth space. I have only done this once, many years ago to make differential pinions for a 1901 Toledo steam car. If you need bevel gears, best to buy them as stock gears.
There are 8 gear cutters in a set for each diametral pitch in order to cut the full range of teeth numbers, that is from 12 teeth to a rack tooth; that cutter cuts 134 to rack, so if it is not intended to cut that large a number of teeth, it might be dispensed with, but having the whole set is a good thing.
 

Gwil

Swarf
Registered Member
Joined
Dec 8, 2014
Messages
9
Likes
8
#10
Bevel gears. Nice project, but don't forget beautiful, strong pairs of gears are found at the front and back of shaft drive motorcycles. The front pair can be one to one, the back obviously a reduction gear set.

The fronts are found on any bike with an across the frame crankshaft, so you won't be robbing bits of a BMW or an even lovelier Moto Guzzi!
 

whitmore

Active Member
Active Member
Joined
Mar 3, 2017
Messages
312
Likes
187
#11
Nice video. I learned.
So I'd need two gear cutters if I wanted to cut two different sized gears, depending on their size.

I have some pondering to do. I need to make a bevel gear to turn 90 degrees for a knee feed motor.
Everyone who has lost a chuck key needs to make a bevel gear. It is not easy.
Buy a hand-crank drill and repurpose the parts, or get a hobbyshop differential,
or even purchase from SDP either bevel or worm gearbox (both do the 90 degree thing,
but worm gets you a largeish ratio).

SDP prices divert my attention to the hand-crank drill that I'm not really using...
heck, a junkyard car differential would have good heavy bevel gears.
 

Hukshawn

Titanium
Former Member
Joined
Nov 19, 2016
Messages
1,400
Likes
1,010
#12
I would need the gears to be 1:1 or close. Or at least the small gear to be 1.5-2" in diameter.
 

Gwil

Swarf
Registered Member
Joined
Dec 8, 2014
Messages
9
Likes
8
#13
I would need the gears to be 1:1 or close. Or at least the small gear to be 1.5-2" in diameter.
Just saw a couple of Yamaha XV535 front gears on ebay, item number, 121731161402

They look exactly the kind of size you're after. These bikes have been in production for years, breakers are full of 'em.
 

Asm109

Active Member
Active Member
Joined
Aug 29, 2017
Messages
183
Likes
203
#14
Spider gears in a car differential are bevel gears with 1:1 ratios. diameters are in the range you need. Choosing a light duty car or heavy duty truck can fine tune the size you get.
 

Downunder Bob

H-M Supporter - Sustaining Member
Staff member
H-M Supporter - Sustaining Member
Joined
May 16, 2016
Messages
896
Likes
348
#16
You can also get some 90 deg bevel gears from an old outboard motor. you can often find one where the motor is blown but the wet end is ok, should be available cheap.
 

P. Waller

Active Member
Active Member
Joined
Mar 10, 2018
Messages
224
Likes
142
#17
If building a geared assembly from scratch actually making the gears yourself would be terribly slow and costly.
If as you say there is no required pitches or diameters then stock unfinished bore gear blanks and pinion wire are the way to proceed, these are available from many sources. Making gears without dedicated equipment is never as cost effective as buying them from a company that only makes gears. If what is needed is not available then making them is the only option.

For example
http://www.sdp-si.com/products/gears/Pinions-Metric.php
https://khkgears.net/new/bevel_gears.html
https://www.mcmaster.com/#bevel-gears/=1dmhw8f
https://us.misumi-ec.com/vona2/mech/M1000000000/M1006000000/
 
[6]
[5] [7]
Top