Bosun Posted April 9, 2020 Share Posted April 9, 2020 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 Link to comment Share on other sites More sharing options...
davknigh Posted April 9, 2020 Share Posted April 9, 2020 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 1 Link to comment Share on other sites More sharing options...
naugytrax Posted April 10, 2020 Share Posted April 10, 2020 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. 1 Link to comment Share on other sites More sharing options...
Bosun Posted July 8, 2020 Author Share Posted July 8, 2020 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 Link to comment Share on other sites More sharing options...
RobMG Posted July 9, 2020 Share Posted July 9, 2020 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 1 Link to comment Share on other sites More sharing options...
decauville1126 Posted July 9, 2020 Share Posted July 9, 2020 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. 1 Link to comment Share on other sites More sharing options...
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