K & D Mainspring Winder

[Paul Beyer]

Hi, I have a K&D mainspring winder #128 which I acquired at a regional show. It's a nice set in a wooden box and will handle from 8mm to 18mm barrels. The problem is the nib is worn off the crank mandrel and will no longer grasp the end hole in the mainspring. There's a through hole in the end of the mandrel where the nib is pressed in. This hole is about .050 in diameter.
Has anyone had any luck pressing, drilling or removing the old nib and replacing it? The mandrel is mild steel but I suspect the nib is very hard. Probably used to be square for either left or right hand winding. Any ideas or information would be greatly appreciated.

[Paul Beyer]

Hi, I have a K&D mainspring winder #128 which I acquired at a regional show. It's a nice set in a wooden box and will handle from 8mm to 18mm barrels. The problem is the nib is worn off the crank mandrel and will no longer grasp the end hole in the mainspring. There's a through hole in the end of the mandrel where the nib is pressed in. This hole is about .050 in diameter.
Has anyone had any luck pressing, drilling or removing the old nib and replacing it? The mandrel is mild steel but I suspect the nib is very hard. Probably used to be square for either left or right hand winding. Any ideas or information would be greatly appreciated.

[mikeh]

Paul,

Been there!

I was able to remove the old nib by driving it out from the opposite side of the mandrel. I think I used an old screwdriver tip to drive it out. As you can probably tell once you get it out, the outside diameter of the nib has to be worked down a little. This would ideally be done on a lathe, but I was able to put it in a pinvise and file it down. I then drove it back in with a punch until the new shoulder was flush with the mandrel.

Although it's not the perfect solution, it only took a few minutes and it saved me about 30 bucks! I've used it a number of times since and it seems to have worked fine. I guess time will tell exactly how well it worked!

Regards,
Mike

[Paul Beyer]

Mike,
Many thanks for your response. Your advise worked well. I took an old screwdriver bit and ground both ends square and made about a 1" punch. I was able to drive the nib out to where it would engage the mainspring and get the job done. When I have a little more time, I will replace the nib. Thanks again.
Paul