Atlas 618 4 jaw chuck won't come off

[David S]

Just an update. As a last restort I tried something and it worked. Please cancel my request. Sorry.



Hi Folks,

I have been hobby machining on my Atlas 618 for 40 years using both my screw on 1/2" jacobs chuck and my 4J.

After a fair amount of maching on a 4" aluminum bar I tried to get the chuck off and no way. Usually I grab the belts, insert the key and give it a gentle tap and off she comes. But no way this time. I dont want to screw up the bearings or anything, but so far with reasonable force I can't get it to budge.

And tricks that may help?

Thank you

David

 

[Jordan]

I'd try a split circular aluminium clamp, connected to a bar, clamped over the gear on the LH end of the headstock spindle.
Place something between a chuck jaw and the bed to prevent it rotating while you lever the bar.

Or if you are brave, momentarily switch on in reverse, with the chuck chocked with some hardwood between jaw and bed.

These methods avoid breaking gear teeth, as when locking the back gears.

Jordan

 

[David S]

I'd try a split circular aluminium clamp, connected to a bar, clamped over the gear on the LH end of the headstock spindle.
Place something between a chuck jaw and the bed to prevent it rotating while you lever the bar.

Or if you are brave, momentarily switch on in reverse, with the chuck chocked with some hardwood between jaw and bed.

These methods avoid breaking gear teeth, as when locking the back gears.

Jordan

Thank you Jordan,

Yes my manual recommends locking the back gear with out pulling the pin. HOwever when I look at those old gear teeth I didn't want to go there.

After trying everything that I normally do. I just inserted the index pin into the big gear... a reasonable tap and it was loose. I figured that I hardly ever ever use the index pin, so if it broke no big deal.

Any way it is off, and I thank you for your comment.

David

 

[Ray C]

Glad it had a happy ending....

BTW: If you ever do any form of an interrupted cut (such as knocking the corners off a square plate etc), each little impact is tightening the chuck. In those situations, it's good to periodically check that the chuck can be removed. -Ask me know I know...


Ray

 

[David S]

Glad it had a happy ending....

BTW: If you ever do any form of an interrupted cut (such as knocking the corners off a square plate etc), each little impact is tightening the chuck. In those situations, it's good to periodically check that the chuck can be removed. -Ask me know I know...


Ray

And yes Ray there were some interrupted cuts. So that could have been part of the problem.

Anyway all is good now.

Thanks to all.

David