Is this part of a sensitive drill attachment?

[woodchucker]

look at the old thread "how many drill chucks are enough" my images of part of mine are #4

ok, I did...
Dave, and Dave.. you are both horders.

How many drill chucks are enough?

So after getting a Jacobs 16N chuck cheap the other day I started wondering how many drill chucks I had. So I gathered up all the ones that were not attached to portable drills. At what point are you a hoarder? And yes I have keys to fit them all. While I was gathering the keys I found...

www.hobby-machinist.com

I rest my case.

 

[ericc]

it looks to me as just a chuck that came from a hand drill and a shaft that fit with a 3/8-18" thread. the sleeve with a cut out may have been a homemade bushing. the gear probably has nothing to do with it. I have many nice hand chucks that I have saved with many shafts that have the correct threaded end to fit the chuck. I have at least 30 that look the same as yours, ready for future projects.
Dave

Hi Dave. I pulled the gear off the shaft with a small gear puller. It was on the shiny spot. I looked all over for the mating piece, but could not find it. I might recut the sliding section and use it. I only needed a sensitive drill attachment once in the last 5 years, and was able to get through the job by very gently pecking and watching the thin drill for runout. If the sliding fit was precise, it's obvious that this would be an improvement.

 

[mmcmdl]

There are easier ways for drilling small diameter holes without fine feed chucks .

 

[Dave Smith]

Eric,
the matching missing part to your gear is a pinion on the end of the armature shaft, which would just gear your spindle speed slower, which would not be good for tiny drills. if you made a small multible step pulley to press on your 1/2" shaft with bearings then you could use O ring to power it from a motor to get your higher speeds for tiny drills. if you need O ring for drive belt just let me know or if you really need the pinion shaft to match your gear.
Dave