Large Turning Part

[[email protected]]

I have a large part to put on a Okuma LC-30 horizontal Lathe. It would be done in two ops. 1st op would be face then turning a diameter back 1.00" . 2nd op. would be turning a sphere. The problem is the part is 18" diameter x 12" long and weights 880 lbs. Do any of you lathe guys know if the chuck would hold this?

[Guyinthedesert]

depends on the size of the chuck. I've turned 20" dia 4140 in an old WWII Warner Swazey without a problem. Of course, I never stood in the flight path.

[Roger Martin from CNC Software]

Ah.... Warner Swazey lathes, that brings back memories.

 

One lesson learned was not to create programs at midnight and when in a hurry.

 

A minor programming over sight and that 75+ pound slug pulled right out of the chuck, and yanked the cover/door* right off the machine, sending it skyward.

Let’s just say the operator wasn't real happy when it landed on him.

Luckily he wasn't hurt, but certainly more than a little bit p!ssed off!

 

*On these 70’s vintage ‘SC’ type lathes, there wasn't a separate door.

The “door” consisted of a single large “L” shaped piece that was the door & top cover that rolled to the right to access the inside of the machine.

Not the actual machine, but like this ->

[crazy^millman]

You did not say what size chuck you got. I would think about a Dovetail on the 1st side if you think you can machine it off afterwards.

[BBprecise]

We turn 680lb 27" diameter parts with our 18" chucks on a Johnford-ST60. Parts are 4" thick and we chuck on about 2" of it. We also do 900lb Titanium parts that are 37" long and the largest dia is 20" at the chuck. At one spot in the program we actually turn this without a center or steady rest, but we have a 30" dia. ring that bolts on the back of the chuck that goes over the OD of the chuck that we strap the part back against using a groove on the very OD of the part. The jaws themselves ID chuck on the part and are used to drive and center the part. When we don't use the tailstock or steady rest we cap the rpm's at 200. Done hundreds of these and never any problems.