Oliver Whales Win A Kit Kat

[bigben]

I’m after some advice please.
What size ball bearing should I use, any preferences to the ball type?
Also the chrome hammer cover, should the chrome plate part be soldered on, mine seems to have what I guess is a rubber hammer stop missing? Does anyone have a photo of what it should look like?
Thanks

[pennymachines]

The balls are 9/16" chromium-plated hardened steel.
Yes, the face plate should be soldered to the frame, and there should be a steel collar soldered below the aperture to hold a short piece of half inch diam. solid round rubber rod to dampen the hammer arm.

[bigben]

Thank you for this, really helpful.
Paul