Learning to dial in a 4-jaw

[Tozguy]

I am considering making 2 short keys for dialing in the 4 jaw. Any recommendations on the length of the key or the handles? Anyone got an example? What kind of steel would you use? Does it need to be hardened?
I know this was covered somewhere but the forum does not allow one to search for the word "key"! I guess it is too short a word!
Robert

These keys were made up from plumbing fittings found at the local hardware store. They are only used to finger tighten the jaws into position so they do not have a hard life. These have been used for several years now. Once you have the right size pipe plug (this one is 1/4 pipe with a 3/8 square) there are several options for the other parts to get the length and diameter that suits you.


Another idea is to get a piece of square key stock, cut it to length and press a piece of thick hose over it for a grip.

 

[projectnut]

Keep in mind when making your "keys" that you'll be machining stock of varying diameters. The keys should be long enough to clear the jaws and leave enough room for your hand to grip them when the jaws are at their maximum diameter. Short keys work well when the jaws don't extend beyond the body of the chuck, but it hurts like hell when you're opening a jaw and you smack you're knuckles against it because the key is too short.

 

[rwm]

Thanks for these great ideas! I have some 304 and a collet block. The jaws on my Southbend chuck are very stiff. I could not turn the adjusters with that small diameter plumbing tool. Using the plugs is a great idea however. I am thinking of making the keys about 2.5" long with similar length handles. The easiest way would be to put a handle on some square stock I suppose....
I could turn the end of the square stock round and then solder it into a handle...
Robert

 

[Grinderman]

Thanks for these great ideas! I have some 304 and a collet block. The jaws on my Southbend chuck are very stiff. I could not turn the adjusters with that small diameter plumbing tool. Using the plugs is a great idea however. I am thinking of making the keys about 2.5" long with similar length handles. The easiest way would be to put a handle on some square stock I suppose....
I could turn the end of the square stock round and then solder it into a handle...
Robert

I’ve been using these stubby 3/8 ratchet handles and extensions for years on my 4 jaw. A t-handle was always in the way on the backside. Pretty cheap to buy no name stuff at the big box stores.

 

[rwm]

I have a key that is about .332" or 8.4mm. What is the nominal dimension of this key? It falls between 5/16 and 3/8". Is it a metric 8.5? I have not seen that.
Robert

 

[mikey]

The key for my Emco/Rohm chuck is 0.35"/8.9mm. Wierd. The good thing is that you can make it whatever you want.

 

[rwm]

The key for my Emco/Rohm chuck is 0.35"/8.9mm. Wierd. The good thing is that you can make it whatever you want.

Sure can!
I'm thinking about 2 of these as a key handle:

Apologies to David for the thread abduction!
Robert

 

[DavidR8]

No worries @rwm, I’m soaking up the knowledge!


Sent from my iPhone using Tapatalk

 

[mikey]

Sure can!
I'm thinking about 2 of these as a key handle:

Might be a little challenging to get enough torque with those. I was going to suggest T-bars long enough to get some leverage because you'll need it.

 

[Tozguy]

The original T wrench that came with the chuck can still be used for the last step of fine adjustment and torquing the jaws.
My twin stubby wrenches are only used get the jaws quickly in position to receive the work and then finger tighten the jaws to center the work as close as my eyeballs can make it. Then an indicator is installed and the single T wrench is used to finish the job.
Knurled surfaces on the stubby wrenches offer sufficient grip for my fingers and the jaws move easily when there is no pressure on them.