Lathe - Running larger bar stock

[rwskinner]

I know plenty of folks that remove their hydraulic chuck and stick on a manual chuck for larger jobs when need be. Most leave their draw tube in there and just suck it back.

My lathe has a 3.125" Spindle bore, but with the drawtube and hydraulic chuck, the largest bar is 2.5".
I need to run some 3" bar, but not all the way thru the spindle, but around 3' sections.

Is it okay to remove the draw tube and hydraulic chuck, install my set-tru then just run it? IOW, will I hurt anything, or contaminate anything running with the draw tube removed? Coolant, Chips.... It seems like it should be fine but trying to avoid unforeseen disaster by asking.

 

[Garwood]

I know plenty of folks that remove their hydraulic chuck and stick on a manual chuck for larger jobs when need be. Most leave their draw tube in there and just suck it back.

My lathe has a 3.125" Spindle bore, but with the drawtube and hydraulic chuck, the largest bar is 2.5".
I need to run some 3" bar, but not all the way thru the spindle, but around 3' sections.

Is it okay to remove the draw tube and hydraulic chuck, install my set-tru then just run it? IOW, will I hurt anything, or contaminate anything running with the draw tube removed? Coolant, Chips.... It seems like it should be fine but trying to avoid unforeseen disaster by asking.

You gotta pull the actuator completely off to do that. Whatcha gonna do with the actuator? Plug all the hoses and remove it?

 

[rwskinner]

You gotta pull the actuator completely off to do that. Whatcha gonna do with the actuator? Plug all the hoses and remove it?

Why do I have to remove the actuator for? Draw tube just unscrews. My bar stock won't run that far back to the actuator so it's I.D. isn't an issue. Why can't it just sit back there and idle?

 

[Garwood]

Why do I have to remove the actuator for? Draw tube just unscrews. My bar stock won't run that far back to the actuator so it's I.D. isn't an issue. Why can't it just sit back there and idle?

How long is your drawtube? You said 3' material in the spindle. Most lathe spindles are a fair bit shorter than that. The drawtube screws into the front of the actuator. Actuator and rotary union are typically 12-18" long bolted to the rear spindle face.

If you can fit the length you should be fine. Drawtubes are often loctited into the actuator. Definitely use a tight fitting tool to take it out.

 

[rwskinner]

How long is your drawtube? You said 3' material in the spindle. Most lathe spindles are a fair bit shorter than that. The drawtube screws into the front of the actuator. Actuator and rotary union are typically 12-18" long bolted to the rear spindle face.

If you can fit the length you should be fine. Drawtubes are often loctited into the actuator. Definitely use a tight fitting tool to take it out.

Thanks. I have 28" to the front of the actuator to the chuck jaws. So I can cut the material around 34" and should be fine. I have to cut lots of 7/8" thick parts so I will slice off about 5-6 or so then do a pull and repeat. Way less waste like that.

 

[guythatbrews]

It wouldn't hurt to stuff a rag back in there to keep crap out of the acutator threads.

 

[rwskinner]

It wouldn't hurt to stuff a rag back in there to keep crap out of the acutator threads.

Good idea. Or maybe turn an aluminum slug with a couple o-rings and just shove it back there. That ought to keep crap out.

 

[Milland]

Good idea. Or maybe turn an aluminum slug with a couple o-rings and just shove it back there. That ought to keep crap out.

Agree, but make it Delrin, not Al. I'd also suggest putting a "knife edge" (like a hydraulic piston seal) on the side facing the chuck so that if you do get chips down the bore they get "scooped up" by the knife edge, rather than going in between the plug and the spindle bore.

 

[rwskinner]

This was no sweat and worked just fine. I just had to move the foot pedal for the chuck!