The Jacobs Chuck trivia!!!

[I.RonMann]

ACTUALLY it is the Jacobs Chuck "Hmmmm":thinking:

I have a Jacobs No. 18 Super Ball Bearing chuck. That's the one that has a 1/8"-3/4" capacity. THIS is what is weird. The taper for the mounting. It measures: .525" and tapers down inside to .500" the taper length is 1.800" Rather small and long. I am not sure which "Jacobs" taper it is, or if it is a custom one-off. The chuck came with a machine shop GOOB sale grab bag, and I didn't notice it till like a week later. ANYONE ever see a Jacobs with this size arbor hole? Pics:





It's up to you to save me a trip to KBC, PLEASE! It's like at LEAST 10 min.s from here...:nuts:

 

[4GSR]

That's a plug that someone made to adapt to a smaller arbor. The easiest way to get it out is to open the jaws to its fullest extent and drill a hole down inside, where the drill bit shank normally goes. Drill thru to the bushing and stop. Take a steel bar insert into hole and drive out the bushing. Once done, polish out the tapered bore in the chuck body and find a new chuck arbor with a no. 4 Jacobs taper by what ever taper you want on the other. Install and you are ready to go.