[size=large]Gear-Slip No More[/size]

After becoming quite frustrated with so many trains that came in bulk purchases having split or stripped axle cogs, probably due to holding the train still while the motor is running, and not being satisfied with Super gluing the gear as, although better, still would slip, I picked up a bunch of replace gears from the Auctions on Yahoo Japan. This is a short tutorial of how I went about replacing the gear with a new one.

First I purchased a set of 15 – 14 tooth gears and 40 – 12 toothed in one purchase from a seller at the Yahoo Japan Auctions. There are different size (amount of gears) sets but I went for a big set as they weren't that expensive and would like to have more around if this works out.

Remove one drive wheel from the axle. This can be achieved easily by pulling as you rock the wheel back and forth. Count the teeth and remove the old, split/stripped, gear by sliding it along the axle and off or by simply spreading the split or cutting it off.

Next I created a jig that would allow the axle to pass through and make perfect, even contact with the new gear so as not to damage it. I used scrap pieces of styrene plastic sheet and super glued several pieces together. Then drilled a hole slightly bigger than the axles diameter all the way through. I made reference lines on one side to line up the gear and axle before pressing on the new gear. You don't want the hole to be too large as the jig may press against the gear's teeth instead of the hub and possibly damage them when pressing with clamp or vise.

Select the corresponding gear with the same number of teeth as the old gear. You will notice in the pictures that I used a cheap, Dollar Store hand clamp to press on the new gear. I found this to be good until the last part when it wasn't strong enough the finish the press. I then finished up on my bench vise using a styrene spacer on both ends so the jaws of the vice did not mark the wheel face. A small hobby vise would also work as long as the jaws opened wide enough.

You will also notice the the width of the styrene jig is exactly the depth needed to press on the gear to the short side of the axle. I did this so there was no chance that I would screw up and press it on too far. This works perfectly if the wheel that you pull off is the short side one. If by chance, has happened to me, the long side wheel comes off I just added a few small washers to the back side of the jig so the gear would slide further down the axle. I suppose one could make 2 jigs, one for the short side and one for the long as its cheap and easy to make.

All thats left to do is press on the removed wheel using the hand clamp and styrene spacers.

Well there you have it. The finished product is like new and “Slip No More” I hope I didn't miss anything in the explanation of what I did. Feel free to comment as there may be other ways to accomplish the same thing.