Post by mkl194 on Jun 19, 2015 11:59:20 GMT -5
I've been doing a lot of repair work on European Steam Locomotives for a friend lately and ran into the same problem that I often encounter in repairing older diesel locomotives. Lots of us have old AHM, Tyco, Bachmann, Life-LIke, etc... engines that have lots of sentimental value to us but are plagued by cracked or worn gears.
I did find a source on ebay that sells a bag full of misc. small gears that has turned out to be a goldmine of replacement gears, but that's for another article.
So this last week I was repairing a Piko BR 86 Steam Engine that had an idler gear that was half worn off. The locomotive was unable to move in reverse at all. When I stripped it down and examined the main idler that transfers power from the brass worm to the wheels I noticed that the teeth that make contact with the worm were shaved down to half their original width. A replacement gear was not an option on this model. The wearing was from a bind in the linkage and the wheels not being quartered. Once that was fixed, there was still no reverse.
After exhaustive research I had settled on a method of repairing the original using tinfoil cladding and baking soda and superglue to rebuild each tooth. That process is delicate and difficult. I got that idea from a youtube video showing how to fix a paper shredder and a site that shows how to repair quadcopter gears.
The first step was to get the tinfoil perfectly mated to the gear. I cut a strip and loosely wrapping it around the gear and the used the worm to make sure it was perfectly mated to the gear. Then a strange thing happened. I noticed that with just the foil on the gear both forward and reverse worked better than ever. So I folded over the tinfoil and added a little lithium grease and tested it again. The results were amazing.
A few rips and tears appeared here and there, but the foil cladding held once seated and the locomotive ran much smoother than another BR 86 I already had serviced. The foil cladding is a much better mate than plastic for the brass worm, it's smooth and really takes a beating.
I tested it on the bench at full power in both directions for what would probably be years of normal use and once it had settled there was no further deterioration. If the cladding ever fails, I'll just wrap it again. Under normal operation with even a heavy load on it the foil holds nicely and serves as a barrier to prevent the metal to plastic shaving that had occurred in the past.
Here's a picture of the working gear, not pretty, but it actually works very well:
The next step is to apply this method to a thinner and smaller gear.
I did find a source on ebay that sells a bag full of misc. small gears that has turned out to be a goldmine of replacement gears, but that's for another article.
So this last week I was repairing a Piko BR 86 Steam Engine that had an idler gear that was half worn off. The locomotive was unable to move in reverse at all. When I stripped it down and examined the main idler that transfers power from the brass worm to the wheels I noticed that the teeth that make contact with the worm were shaved down to half their original width. A replacement gear was not an option on this model. The wearing was from a bind in the linkage and the wheels not being quartered. Once that was fixed, there was still no reverse.
After exhaustive research I had settled on a method of repairing the original using tinfoil cladding and baking soda and superglue to rebuild each tooth. That process is delicate and difficult. I got that idea from a youtube video showing how to fix a paper shredder and a site that shows how to repair quadcopter gears.
The first step was to get the tinfoil perfectly mated to the gear. I cut a strip and loosely wrapping it around the gear and the used the worm to make sure it was perfectly mated to the gear. Then a strange thing happened. I noticed that with just the foil on the gear both forward and reverse worked better than ever. So I folded over the tinfoil and added a little lithium grease and tested it again. The results were amazing.
A few rips and tears appeared here and there, but the foil cladding held once seated and the locomotive ran much smoother than another BR 86 I already had serviced. The foil cladding is a much better mate than plastic for the brass worm, it's smooth and really takes a beating.
I tested it on the bench at full power in both directions for what would probably be years of normal use and once it had settled there was no further deterioration. If the cladding ever fails, I'll just wrap it again. Under normal operation with even a heavy load on it the foil holds nicely and serves as a barrier to prevent the metal to plastic shaving that had occurred in the past.
Here's a picture of the working gear, not pretty, but it actually works very well:
The next step is to apply this method to a thinner and smaller gear.