Emergency mainspring winder

[HectorLooi]

What do you do when the correct size mainspring winder you have has an arbor that looks like this?

This is exactly the situation I encountered last night. I was servicing a Slava 2428, twin barrel movement. The barrel is so small that the only winder that could fit was a Watchcraft #2. But my arbor looks like it got chewed by a dog.

I remembered a post a couple of months ago about a homemade mainspring winder using a plastic sheet and a pinvise to hold the actual watch barrel arbor. Then it hit me. I could mount the barrel arbor into a pinvise and wind it directly into my winder. 

Initially when I tried it, the mainspring kept twisting and buckling and wouldn't wind nicely into the winder. I had the idea of cutting a washer to cap the open end of the winder. When I finished doing that, I looked at the washer and thought it looked a lot like the barrel cap. I took the barrel cap and realized that the barrel cap fits perfectly.

So I mounted the spring and wound it into the winder easily.

[Kalanag]

Well done!

See here for reference:

stopgap-mainspring-winder