I'm in the middle of resurrecting a Bachmann Spectrum 2-8-0 Consolidation. When power was applied, the motor spins but the locomotive doesn't move. These are famous for the gear on the motor shaft split, and I had a motor assembly, so I wasn't worried. But when I began to disassemble the locomotive I saw that the gear on the driver shaft was off to one side. I recentered it and when it got to the middle of the shaft it became very tight. A tight enough fit that I assumed that all was good. But when I went to have the loco run on its own power again, somehow the gear slipped to the side again. So now I am wondering if any of you have ever had any luck gluing or epoxying a gear to a shaft? I've never tried it, but I have nothing to lose. I just wanted to check if any of you have any experience with the likes of this before I try it.
I tried it with an MDC Shay - their motor shaft gear has a nasty tendency to come loose from the shaft, but stay aligned on the other gear, so the motor shaft spins inside the gear and the loco goes nowhere in a very noisy way... The repair was of short duration. Since there's a problem with the drive train itself sticking, the glue fix lasted a grand total of 3-1/2 seconds... The problem with the glue solution is that motor shafts in general are very smooth metal rods, and glue doesn't hold very well to them. From all that I determined that the gear comes loose because of the the lack of synchronization between the actual drive shaft under the engine and the "show shaft" on the side of the Shay. I tried glue on another smooth stainless steel item to keep it's rubber handle in place recently, with the same result.
Since you have nothing to lose, you might want to try a trick I've used in the past. If there is enough space to not cause interference, you can wrap some very fine thread around the axle on both sides of the gear and soak it with super glue. Additionally, if you sprinkle a tiny amount of baking soda on it, it will strengthen it even more. Here's a pic to try and show what I'm talking about.
That's genius! I recently saw a video on plastic repair techniques that resemble that. It's your baking soda idea (used in that video for several examples) that tickled my neurons. I even constituted a sort of a kit to do such repairs, with a wood-burning iron, some wire mesh netting, etc. I think I have some baking soda lurking in the deep dark recesses of a cupboard... I sense a mad-scientist-type experiment in my future...
The loco moves with the gear epoxied, but the gear is cracked and there is a clunk every time the crack gets to the worm gear. Oh well, it was worth a shot. She'll sit on the shelf until I can find a set of drivers for her.
3hat i have4 done in past was slide gear over a bit then file some grooves in the shaft then super glue that area and slide gear back one where it belongs. worked pretty well.
I took my Shay kit out today - forgot to mention that in my previous post here - and then rediscovered that 1) I had used epoxy and it worked and 2) that it wasn't the gear but the short u-joint between (and on) the motor shaft and the gear shaft that was the problem. That and my memory... The main problem is a sticking drive train because of the Shay mechanism (for show - doesn't really move the loco) on the right side of the engine not meshing properly with the drive wheels.
I had glued a gear with epoxy, but the axle had a kind of rough texture and it gave me no issues, also it had a kind of collet so also the gluing surface was larger.
Don't know how it works on plastic, but I used green Loctite to restore the press fit on a bearing once. Spilled a little on the oil flinger and had to stand there for 15 min. spinning the flinger by hand to keep it from seizing up. The repair has worked fine for 20 years I'd do a little more research first.
