- Joined
- Feb 17, 2013
- Messages
- 4,403
I was missing the key for one of my Jacobs 6A chucks. Searching the Jacobs website, 6A doesn't appear at all ... must be an obsolete product. Some other searching finally led me to the K3 key. Ordered two of them from Enco on their 25% off/free shipping deal. As usual, Enco delivered quickly.
But then the fun started! The chuck was kinda old, and its teeth a bit worn. So the dad-ratted key would hardly engage the teeth! I have another 6A chuck. Its no-name key works well on both the newer and older chucks. I looked to see what was different. Turns out that the pinion teeth on the "good" key start out at a significantly larger diameter than those of the K3.
So I pressed out the handle, chucked the key up in the lathe, and cut back the "face" of the pinion with a carbide bit. Fortunately, the interrupted cut caused by the pinion teeth did not ruin the bit! After checking the fit on the chuck and shortening the now-too-long pilot pin, I pressed the handle back in. Works! The photo shows the (spare) "original" and "modified" chuck keys.
PS - the key is indeed marked as being a Jacobs K3, so I'm confident it's genuine. But guess what ... it's made in China.
But then the fun started! The chuck was kinda old, and its teeth a bit worn. So the dad-ratted key would hardly engage the teeth! I have another 6A chuck. Its no-name key works well on both the newer and older chucks. I looked to see what was different. Turns out that the pinion teeth on the "good" key start out at a significantly larger diameter than those of the K3.
So I pressed out the handle, chucked the key up in the lathe, and cut back the "face" of the pinion with a carbide bit. Fortunately, the interrupted cut caused by the pinion teeth did not ruin the bit! After checking the fit on the chuck and shortening the now-too-long pilot pin, I pressed the handle back in. Works! The photo shows the (spare) "original" and "modified" chuck keys.
PS - the key is indeed marked as being a Jacobs K3, so I'm confident it's genuine. But guess what ... it's made in China.