Two chuck keys better than one

[cfellows]

A number of years ago I found this 4" lathe chuck at a pawn shop for a price I couldn't pass up so I bought it. It didn't have a chuck key, but the sockets for tightening and loosening the jaws were hexagonal, so I always just used a 7/32" allen wrench to open and close the jaws. Recently, I adapted the chuck to my HF minilathe and trying to center work with a hex key was a lot of trouble. Inserting the long end into the chuck didn't work because the short end didn't provide enough leverage to turn the key. Inserting the short end in the chuck didn't work well, because the long end would interfere with the headstock, lathe bed, or any other parts sticking out.

I decided to make a chuck key for it, then it occured to me that two chuck keys, one for each of the two jaws being adjusted at the time might be more useful. Turned out, I was right. Loosening one side while simultaneously tightening the other side is way easier than switching a chuck key back and forth from side to side.

I made the main shank for mine out of 1/4" drill rod. I gripped the rods in a 5C collet in my hexagonal collet block clamped in my milling vise as an indexing device and milled 6, 3/8" long flats. The handles are made of 5/16 cold rolled steel. I drilled a 3/16" cross hole and shouldered down the end of the shank to fit in the hole. I welded the shank to the handle on the outboard side then ground it off smooth with my belt grinder.

Nothing fancy, but a tip I thought might be useful to others.

Chuck

 

[T70MkIII]

Very nice, Chuck.

 

[ShedBoy]

I watched a clip on youtube by Tubal Cain and he says the same thing, two are better than one. They are some nice looking keys Chuck. I have 3 because one is always somewhere else.

Brock

 

[jct842]

the keys for my 3" and 4" 4 jaw are the same drive size. I also watched tubal caims video, and it works like a charm. I cut my centering time to 1/3 or 1/4 the time it used to take. john

 

[mzetati]

At some point I decided L-shaped allen keys were not much handy when fiddling with the small screws I'm using: cut the shorter of them with an angle grinder and made some quick aluminium handles with a drilled hole about 2cm deep. Hole diameters were somewhere between the included circonference into the hex and the ones passing on the vertex.
The keys were inserted using the bench vise as a press, after slightly tapering one end on the grinder.

On the same principle, I recently made two very short 8mm square keys, to be used with the 4 jaws: reason of making them so short being the lack of space between the chuck and splash shield, on my lathe. Will add a picture of them when I will take it.

The other key in the picture shows the Lathe ER32 collet holder key: had to put an handle on it to prevent me from recyclyng the 8mm rod I was using for the 'curent project'.

Marcello

 

[cfellows]

Marcello, that's a good idea with knurled aluminum handles. I had thought about looking for hex keys with screwdriver handles, but you solution seems better. Have to give it a try.

Chuck

 

[mzetati]

a brass cap, rotating on a pivot, where You can put Your index on while rotating the key among thumb and middle finger would add some pleasant feature to them.
I never got around to it. Someday...
As for purchasing commercial ones: I was never able to find any in the stores ... ..till I had them homemade. (Plenty of screwdrivers and torx keys sets, tho).
Marcello

 

[wheeltapper]

Another key for the 4 jaw is something I keep meaning to do.
I always put pieces of card under the jaws to stop them marking the work and it's 'slacken one jaw, drop the card, fish it out from the muck and put it back, tighten other jaw, turn chuck, slacken jaw, drop card............well you get the picture.

I suppose I could just tape the cards to the work but that's too easy, Isn't it?

Roy

 

[mklotz]

I've been advocating two chuck keys (and a horizontally mounted DI) for adjusting 4jaws for a long time. I think I've published my writeup on the subject here a couple of times.

If you haven't made yours yet, check the available space behind the chuck first. You may well find that a shorter key for the offside hole is a good idea. On my 8" chuck that's certainly the case.

Another hint... On one of the keys, add a 1/4" hex to the end opposite the one that goes in the chuck. This will allow you to use a battery-operated power screwdriver to spin jaws in and out rapidly - especially handy when you need to reverse the jaws.

A power screwdriver bit for the 3jaw is also a good idea. It makes reversing the jaws easier and is an aid to cleaning the scroll. With the jaws removed, I stick a toothbrush in place of one of the jaws and power rotate the scroll thread against the brush to sweep out tiny bits of swarf. Afterwards I repeat the process with an oily toothbrush to lightly lubricate the scroll.

 

[cfellows]

I guess all good ideas have been thought of before. I probably actually saw this idea somewhere else, either Marv's post or Tubal Cain's video or both, but the knowledge sank to my subconscious level then re-emerged as an original idea. Apologies and credits to those who preceded me.

Chuck

 

[mklotz]

Don't sweat the attributions, Chuck. The idea is probably not original with me either. This stuff just keeps getting (re)discovered again and again.

 

[krv3000]

yep anuther good post ;D

 

[mzetati]

Here's my 4jaws keys: I smoothed the angles of the square in the lathe for about an inch, then press fitted into the previously made handle.

Marcello

 

[hobby]

Here's my 4jaws keys: I smoothed the angles of the square in the lathe for about an inch, then press fitted into the previously made handle.

Marcello

I like that.