In my prior post ( And then there were three. A vintage Mr. Machine has joined the crew.) I introduced you to the newest (oldest) member of the Mr. Machine family. Yesterday I set out to see if I could fix Mr. Machine's wheels. Over 60 years of ageing, the wheels on my Mr. Machine had developed some real serious warpage, so bad the the wheels would not make a complete revolution as the inner webbing of the wheels would catch om the fasteners that hold the two halves of the body together. Here are some images of the warpage of the wheels:
After finding a few good articles on unwarping, I built a simple axle to hold the two wheels together so I could apply some tension on the wheels, coaxing them into the correct position. The axle is made of solid 1/4" aluminum rod, with a machined flat ('D' shape) and 1/4-20 threads on each end.
With the two wheels mounted on the axle, I used blocks of wood to tension the wheels into a more suitable shape (wood blocks contact the internal webbing on wheels).
The next step was to heat the wheels up to 160° - 170º F and hold them there for a few minutes and then cool them back down to room temperature. I used a shallow Pyrex dish with a small amount of room temperature water in it to mix with hot water (boiling) from a tea kettle.
Once the water in the tea kettle was hot, I added hot water to the dish while monitoring the temperature. Once I got it up to temperature (as close as I could without overfilling the dish).
With the temperature raised, I keep the parts submerged in the water for 2 minutes and then pulled them out and quenched them in room temperature water in the sink. After removing the blocks of wood, I had two unwarped wheels.
The result was quite amazing. I reassembled the wheels, along with the arms and legs and wound up Mr. Machine for it's test run. Here is a short video of Mr. Machine with his straightened wheels.
Yesterday I was in contact with an eBay seller that had a bunch of new (reproductions - recreated in 2015 from the original molds from Ideal) Mr. Machines. They have been sold out for quite a while, but I contacted the seller to see if they had any returned/damaged/incomplete units that could be sold as parts. I was very surprised to hear that they had one unit with a broken main spring that they would be willing to sell. Still working on the details, but it looks like I will have yet another Mr. Machine arriving soon. In the meantime I do have a couple of other fixes that I am planning on trying with the original unit.
Thanks for reading!
Gene
