Facing an aluminum rod?

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Frank O

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I need to face one end of a 6061 aluminum rod that's 1 5/8" diameter by 12" long. Doesn't have to be beautiful, I just need to get it to sit square on an aluminum plate.

It's been about four years since I've used my lathe (Grizzly G0516, 10x22 Sieg C6 equivalent). If I go that route, first thing I'm wondering is whether a solid rod of that length will be safe in the lathe's three-jaw chuck. If it seems ok, then I need a little remedial refresh on setup. In particular, cutting tool setup -- I have some indexables and the lathe has a basic QCTP. Do I keep the tool holder 90 degrees to the workpiece and extend enough of the tool to cover the 13/16" radius? Or expose less and put the holder at an angle? Also, wondering about optimal speed.

The other thought that occurred to me would be doing it on the mill. Any reason that'd be a bad idea?

Thanks for any thoughts.
 
I wouldn't feel safe with that large of a piece in the lathe without a steady rest to support the other end. Mill might be your best option.
 
Min cutter overhang. Rotate QCTP to get tool access.
If you have a steady rest I would put that on an inch or so from the free end to support it.
 
Steady rest.
Great advice above!

I'm glad you asked and got good, safe advice.
It sure beats a emergency room visit right now (or worse!).

Be safe!
-brino
 
I am assuming your spindle bore is too small to allow you to pass the work through the spindle but the job can be safely and easily done with a steady rest placed close to the far end of the work. To quickly set up the rest, chuck the rod up and then bring the steady rest up close to the chuck and lock it down. Bring the two lower arms of the rest into gentle contact with the work and lock them in that position. Then unlock the rest and slide it down the work until the arms are about an inch from the end and lock the rest in place. Now bring the top arm of the rest into contact with the work and lock it down. Now the work is supported well and you can work safely.

The arms of the steady rest will mark the work piece, even if yours has roller bearings at the tips. To minimize any marks, take a long piece of card stock or heavy paper and cut a strip about an inch wide. Put that strip between the arms and the work and clamp the strip to the steady rest someplace so it cannot move. Then apply some oil to the work and the strip and go. The strip of paper will prevent marring but is thin enough not to interfere with solid support from the steady rest. Works good.

If you're using inserted carbide tooling, much depends on the geometry of the tool. The old style triangular insert tools do not have a built in clearance angle built into them so you have to angle the tool properly. Newer style tool holders, like the SCLCR, have a built in 5 degree clearance angle for facing when the tool shank is perpendicular to the work. If you have the old style tool holder then angle the tool so that the point of contact of the insert to the work is just behind the very tip of the insert. You only need a very small amount of contact to face with.

I would run the lathe at the fastest speed the lathe can run for aluminum, and use WD-40 as a lube.
 
Better than card stock is a piece of emery cloth strip with the non abrasive side to the work, and yes, use oil on it.
 
Thanks for all the great advice. When I search on 'steady rest' I see some different designs from various vendors. Any recommendations on what would work well on my 10x22?
 
Buy one to fit your specific lathe from Grizzly.
 
If you don't have a steady rest, you can drill the end with a center drill and use a center. Mount the bar in the lathe chuck and use a test indicator to center the tailstock end. Tap the bar lightly to adjust. When centered, center drill the end and mount the tailstock center Face as close to the center as you can. Remove the center and drill out the remainder.

If your three jaw chuck is fairly close, you should be OK. If you are concerned, you can use the four jaw. Center as usual for using a four jaw chuck and then move to the tailstock end with the dial indicator and ceck for centering. Tap lightly to center and then gp back to the chuck and recheck and readjust if required. Repeat the process until you are satisfied and continue as above.

Using a CNC center and a custom ground HSS tool will enable you to get fairly close to the center when you face. You will have a divot in the center of your face but the end should be square to the length of the bar.
 
Thanks for the suggestions. RJ's approach sounds good, but I do need to drill/tap a hole through the plate and rod, so I'd have to check out if the divot in the face could affect that.

As for buying a steady rest, Grizzly's site doesn't show any for the G0516, which is discontinued. However, LMS has a #2496 steady rest for C6 lathes which they indicate fits the G0516. Sounds like something I want anyway, and can't argue with local pickup.
 
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