go_away

Author Topic: Good source for lots of small plastic spur gears?  (Read 3139 times)

0 Members and 1 Guest are viewing this topic.

Offline 777funkTopic starter

  • Beginner
  • *
  • Posts: 2
  • Helpful? 0
Good source for lots of small plastic spur gears?
« on: February 21, 2012, 11:27:38 PM »
I'm always working on things and building simple electronic machines for my business. I love automation.

Is there a good source to find spur gears (both single and compound).

Also, is it possible to glue a large gear and small gear, one on top of the other? If not would plastic welding work? I'm guessing the welding could get difficult due to not being able to get in between the two. So I guess gluing or maybe another way?

thanks in advance for any tips!
Nick

Offline joe61

  • Supreme Robot
  • *****
  • Posts: 417
  • Helpful? 16
Re: Good source for lots of small plastic spur gears?
« Reply #1 on: February 22, 2012, 05:57:38 AM »
If you have an old printer that you don't need, take it apart. There are lots of plastic gears in them, and you can salvage some stepper motors too.

Joe

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Good source for lots of small plastic spur gears?
« Reply #2 on: February 23, 2012, 08:15:37 PM »
Hi,

Is there a good source to find spur gears (both single and compound).
Several, but what pitch, axle diameter, material and such are you after?


Also, is it possible to glue a large gear and small gear, one on top of the other? If not would plastic welding work? I'm guessing the welding could get difficult due to not being able to get in between the two. So I guess gluing or maybe another way?
It depends a lot on what you call plastic.
Nylon is used for many gears and it's very unfriendly to bonding, but why not just mount the two on the same axle by friction - and if more is needed, drill and rivet (when on the axle).
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline 777funkTopic starter

  • Beginner
  • *
  • Posts: 2
  • Helpful? 0
Re: Good source for lots of small plastic spur gears?
« Reply #3 on: February 24, 2012, 03:04:41 PM »
Not particular on the plastic. I know many plastics do not bond well. So that's something to consider.

In this case I have need for one gear with a 1/4" o.d. attached face to face to a 5/8" od spur gear. I've considered trying to drill the center hole of the 5/8" o.d. gear just a few thousandths short of 1/4" and press fit the 1/4" gear into the center. Not sure if that would work. The last detail is the shaft size is .080"

I've looked a little bit and it seems to be a tough time finding those gears. The 5/8" gear would need to be 1/8" thick and the 1/4" diameter gear would need to be long enough to be able to pass through the 1/8" thick 5/8" gear and still have a good 3/8" beyond that for the motor's worm gear to mesh with.
« Last Edit: February 24, 2012, 03:07:15 PM by 777funk »

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Good source for lots of small plastic spur gears?
« Reply #4 on: February 28, 2012, 01:27:49 PM »
Hi,

In this case I have need for one gear with a 1/4" o.d. attached face to face to a 5/8" od spur gear.

You don't measure gears in o.d., but in pitch and number of teeth

Take a look at this set. It may be expired, but I have the precise same set from a local hobby shop and Googling "EXPO A26220" should find some.

From the eBay page (which don't give pitch, but this can be calculated from the data they give):

EXPO A26220 - 9 PIECE NYLON GEAR SET
WITH 2mm HOLES
CONTAINS 1 x EACH GEARS
9mm Outer Diameter with 16 Teeth
16mm Outer Diameter with 30 Teeth
22mm Outer Diameter with 42 Teeth
31mm Outer Diameter with 60 Teeth
16mm Outer Diameter with 30 Teeth & 10 Inner Teeth
22mm Outer Diameter with 43 Teeth & 10 Inner Teeth
6mm Diameter Worm 6mm Long
6mm Diameter Worm 10mm Long
2mm Steel Shaft 75mm Long


I've considered trying to drill the center hole of the 5/8" o.d. gear just a few thousandths short of 1/4" and press fit the 1/4" gear into the center. Not sure if that would work. The last detail is the shaft size is .080"

That sounds like a bad idea.
Much better to keep both at an the same axle and then lock them together in some way (bolts, heated needles or whatever).


I've looked a little bit and it seems to be a tough time finding those gears. The 5/8" gear would need to be 1/8" thick and the 1/4" diameter gear would need to be long enough to be able to pass through the 1/8" thick 5/8" gear and still have a good 3/8" beyond that for the motor's worm gear to mesh with.

Check out the EXPO set.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


Get Your Ad Here