Jump to content
 

plastic gear cog


Den Norton
 Share

Recommended Posts

Hi, new to this forum but I have a problem with finding a nylon or plastic gear for a brass GWR Samhongsa pannier tank loco. It has a Taneda coreless motor connected to an enclosed worm & gear cog that sits on the axle drive cog. The nylon gear is 10mm diameter with 21 teeth.If anyone can help me out I would be eternally grateful.

Link to post
Share on other sites

  • RMweb Premium
5 hours ago, sunbeam.20 said:

Have you thought of North West Short Line? There is an online catalogue or email Dave.

Hi Sunbeam, that's a new one on me - good to find more sources!

 

On 27/02/2019 at 10:49, Den Norton said:

Hi, new to this forum but I have a problem with finding a nylon or plastic gear for a brass GWR Samhongsa pannier tank loco. It has a Taneda coreless motor connected to an enclosed worm & gear cog that sits on the axle drive cog. The nylon gear is 10mm diameter with 21 teeth.If anyone can help me out I would be eternally grateful.

Hi Den,

This is a bit of a long answer, so bear with me, please!

I also needed to find a replacement gear (around six months ago) and eventually found a source, so it ended well.

 

You need to give  bit more information on the gear itself:

What is the width of the gear?

Does the gear have a boss too? If so, how wide is that?

What diameter hole does it need for the axle?

Are the teeth cut straight across the gear, or are they at an angle to match the screw of the worm? I assume for the time being that they are straight across (i.e. a spur gear).

 

Next, you need to find the modulus of the gear. This can be found from the number of teeth and the overall diameter, which of course you have already given. My guess is that your gear is mod 0.3, but it could be 0.2 or 0.4.

If you google for 21-teeth spur gear modulus 0.3, a number of sites will come up, some of which will offer the gear. Unfortunately they will offer brass gears, or delrin (plastic) gears by the hundred. What they will tell you though is the diameter of a gear for a given modulus and number of teeth. If the wrong diameter is given, then look for modulus 0.2 or 0.4 as appropriate.

 

Once you have the modulus confirmed, have a look at this site (you may need to look for and click on the USA flag at the top if your linguistic Czech isn't up to scratch at the moment).

 

On the left side of the screen, click on 'Převody a převodovky' (or 'gears for models' if you have found the language flag) and modulus 0.2, 0.3 and 0.4 are listed as subdirectories. Then you can scroll through the listings to find the number of teeth and hole diameters you need. They offer both the spur gear version and the worm gear version, (also worms too). The prices are not that bad, especially the P&P. There may be a delay of course if they haven't got the gear you want in stock.

 

Hope this helps.

 

Dave

Edited by DIW
Worm gears!
  • Informative/Useful 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...