Working on clockwork/windup trains is a subject that comes up once in a great while on this forum. I realize that those of us who are fans of clockwork are a small niche in the world of operating & collecting O gauge trains, and I suppose that people tinkering on their windups are a niche within a niche! However, the finicky little mechanisms can be repaired, and it is my hope to use this thread to encourage others to tackle those repairs.
As an introduction, I'm going to post some pictures from a project I did a few years ago, a little Ives No. 6 that I bought at a train show for twenty bucks. The locomotive was missing a wheel, the cowcatcher was broken off, and the motor looked like it had exploded. In fact, a gear had stripped out, which had allowed the rapid release of the energy stored in the mainspring. The first step in getting the locomotive running was to get the damaged parts out of the motor:
In this case, the motor did not need to be completely disassembled. The mainspring was removed, the remaining wheel on the drive axle unscrewed (one very nice feature of Ives clockworks), and the sideplates popped loose from the round crossmembers at the front of the motor.
Ives clockworks typically use a round crossmember to hold the sideplates together. The crossmember has a smaller diameter area machined on each end that passes through a hole in the motor's sideplate. The end of it is swaged (or peened) over to hold everything together. It isn't unusual to have to drill these out, and machine new crossmembers in order to reassemble the motor. In this case, I was fortunate that the sideplates came loose from the crossmembers without having to drill them.
The motor itself had a couple of issues. First off was the stripped gear:
Now, this has been quite a few years ago, and I've had a lot of windups go across the workbench since then! However, to the best I can remember, I reused the big gear and the shaft, and replaced the pinion gear... but for the life of me, I can't remember what that gear came from! It wasn't from an Ives motor, and it is wider than the original gear - but, it is the same pitch and number of teeth, so that is what was important. I pressed the gearset off the shaft and pressed the pinion out of the big gear (they are two separate parts that are swaged together). The "new" pinion was turned down on one end to fit inside the big gear, and the two joined together. The gearset was then pressed back on the intermediate shaft:
With that problem solved, I had to turn my attention to the next problem, one that is common to Ives clockworks - the governor was broken. Ives motors have a spring wire that is formed into a shape to work as a centrifugal governor, and that spring wire is soldered to the governor shaft. The spring expands at speed and strikes a crossmember, which keeps the motor from overspeeding. It is very common for that spring to come unsoldered, or break, and often it is missing altogether. In this case, it was missing. I've never had good luck making replacements, so I decided to adapt a Marx centrifugal governor to the motor. This particular Ives motor is considerably narrower than a Marx motor, so it was necessary to shorten the Marx gear/shaft, and machine a new end on it. In a case of "It's better to be lucky than good", the Marx governor gear is the same pitch and tooth count as the Ives. The picture below shows (from left to right) the stock Ives governor pinion (missing the spring), the modified Marx governor, and a stock Marx governor for comparison:
The Marx governor is meant to rotate inside a drum, so I soldered a Marx governor drum to the inside of the Ives motor.. which is a bit tricky to do with a partially assembled motor:
Once that was done, the intermediate shafts and modified governor were installed and the motor reassembled:
Now, I was still missing a drive wheel. I didn't have an Ives driver in the parts box, but I found an American Flyer clockwork driver that matched the diameter of the Ives wheels, and had a very similar spoke style. If you look close, you can see that it is different, but for this project it was close enough. However, the problem is that the Ives drivers are threaded so they screw onto the drive axle, and this driver wasn't. I had to bore the driver out, machine a hub out of brass, and install it in the AF wheel.
This is the AF wheel after being bored out. A smaller diameter is used on the outside than on the inside:
The hub was machined out of yellow brass. The upper end would go to the inside of the wheel. It was necessary to counterbore the inside so that the wheel would sit on the right spot on the axle, keeping everything in gauge. The other end was machined slightly smaller to fit in the smaller hole on the outside of the wheel:
The hub was installed into the wheel, and the outer end swaged to fasten the wheel to the hub:
And that was the majority of the work done. The oddball driver was given a quick coat of dark red paint in an attempt to match the original wheels. As mentioned earlier, the cowcatcher had been broken off the body at some time in the past, so I ground the broken area smooth and touched it up with a bit of black paint to hide it. I like the way the loco looks without the cowcatcher, like an old-timey 0-4-0 switcher running around the layout!
The locomotive runs nice and slow with the Marx governor, which is more of a happy accident than any credit to my engineering skills. The little Ives has a LOT of miles under its belt, having been rebuilt and running for 7 years as of this writing. Hopefully it will be running in another two years for its 100th birthday!
Anyone else have clockwork repairs they would like to share? Maybe something that is in need of repair? I've got plenty on my shelf to be worked on...