Motor Axle Dilemma

[Bosun]

Hello,

I'm new to this forum and I may be posting in the wrong area - just let me know. I model American HO, but the question is probably not unique to US HO.

 

I have some old brass models which are wood burning. They look fine but are best re-motored. I have some nice Mashima motors to do the job, their axle diameters are 2.0 mm. The existing worm and round gear look to be in good condition and I'd like to use them. However the old motor axle is 3/32nds inch or about 2.4mm.

 

Do you have any ideas how I can proceed?

 

All the best,

 

Art

[davknigh]

Hi Art,

 

Do you have a lathe, or a friend with a lathe? Assuming you can get the worm off the old motor ( usually easy enough with a small pin punch) get a sleeve turned down to fit over the Mashima motor shaft and inside the worm hole. It might end up being easier if the worm was drilled or bored out to a larger size so you could use a stock size of tubing from the likes of K&S.

 

HTH

 

David

[naugytrax]

Northwest Short Line sells "shaft adapter bushings" including 2.4mm (3/32inch) OD, 2.0mm ID. I used one to replace the Airfix motor in my GWR 14xx with a Sagami unit.

Their catalog is here: https://nwsl.com/collections/shaft-adapter-bushings/products/bushing-shaft-adapter-reducer-2-0mm-id-x-2-4mm-od-x-3-0mm-l-steel-2-pkg

They seem to have closed for the duration, but I expect they'll be back when this unpleasantness is all over.

[Bosun]

Hi, both replies are very helpful. I was able to find some brass tubing (id 2.0, od 2.4 from Eileens Emporium in the UK). It was actually just over 2.4mm and I was able to open the the hole in the worm gear by the smallest amount  and it worked! The locomotive runs beautifully. Thanks! Art

[RobMG]

If you have a small lathe, the answer is simple, you could make sleeves for the motor shafts.  

The only other thought I have is to see if you can get some brass tube to make sleeves out of.   Recently I needed to fit fine scale wheels in place of Lima coarse wheels , but the Lima wheels had 2.5 mm axles, and the new wheels were 2mm .  I found I could get brass tube with 2.5mm  od x 2mm id  that solved the problem . If however your motor shafts are indeed 2.4mm  you might have difficulty finding the right size.  You could though, get the 2.5 tube and drill or ream the holes in the gears to 2.5mm.   

That is about the only way I can see of sorting the prob..   You might feel that is taking a risk with irreplaceable parts.

Having a lathe is a great benefit of course.  Another way comes to mind, which I would probably do  is to make a piece to fit inside the gears, Solder it in and then drill it to the required size .  Still sleeve of course...

I don't suppose this is of any help, but just my suggestion..

 

Rob

[decauville1126]

There is a group/forum which deals with reworking drive trains:

 

https://groups.io/g/RepowerAndRegear/topics

 

Could be that a posting on there might bring forth some info if someone has already dealt with the same issue or model.