D1-3 cam lock too tight

[Karl_T]

My monarch 10EE uses D1-3 cam locks to install the chucks.

One of them has froze on too tight. I just broke my second 5/16 lathe key trying to open it. It twists right off at the base. This small a chuck key twists off pretty easy. I'll guess at maybe 75 ft.lbs.

Before I resort to drilling out the cam lock and ruining the chuck base plate I'd like to try one more time. What's the most durable key i could make?

idea one - make a holder for a 5/16 HSS tool bit.

idea two - buy a 1/2" impact 6" long extension and mill it down to 5/16 square on the end.

Proto 1/2" Drive Impact Socket Extension SAE J7184P | Zoro

Order Proto 1/2" Drive Impact Socket Extension SAE, J7184P at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.

www.zoro.com

idea three make one out of some grade of tool steel and heat treat - need specifics to try this. Not to hot about this as my heat treat facilities are FAR from perfect.

Suggestions??

 

[markba633csi]

I would buy a 3/8" piece of tooling and grind it down to 5/16"
That would be the least amount of grinding for a tool you only need once
I imagine you've already slathered the chuck with penetrating oil of all kinds?
Heating might help

 

[Dabbler]

Here goes: get a 5/16 square impact bit that you can use with a impact driver, NOT an impact wrench. You don't want 1000s of ft-lbs of torque here, but a lot of gentle impacts can make a difference. Higher torque will cause even more problems. For instance the M12 impact screw gun tops out at just under 100 ft lbs, but delivers 3500 bpm. and you don't need to top it out, just 1 second bursts, to see if you can free it up.

I have the dewalt impact tool as well and it delivers a little more torque at around 1800 bpm, which would also be a good choice - again, if you are careful.

These impacts can do far less damage than gronking on a chuck key.

 

[Karl_T]

if you can find such a thing as an 5/16 bit to fit an impact tool, I am all in. Just searched again, no joy.

 

[Nutfarmer]

Grind down an impact extension to fit. The impact sockets and tooling are better metal than the hand style ones. Is it possible that the cam could have been tightened the wrong direction from the others so it maybe tightening and not loosening

 

[ddickey]

@Karl_T Just a 5/16" 1/2" or 3/8" socket or a 1/4" driver bit depending on what kind of driver you have.

 

[rodm1]

Maybe a impact or an air hammer protect the surface and don't get on it to hard. Just try to vibrate the internal parts. A tool truck will be able to get you a socket if they don't have one.

 

[Dabbler]

if you can find such a thing as an 5/16

you can get a 3/8 socket adapter for a drill driver. and modify it (your tooling will be different than mine), In my shop, surface grinder.

 

[ddickey]

@Karl_T Are the other 2 camlocks loose?

 

[Karl_T]

YEP ONLY ONE LOCK IS TIGHT, YEP KROIL.

OK I will look to see if they make such a thing as a 3/8 impact extension. Otherwise cut down a 1/2" extension