Using a box tool

[jimsehr]

A guy at pm site had some cutters for a box tool and he didn't know how to use them so he gave them to me. And I made a short vid to show him how they were used. Maybe some of you might be interested in seeing a home shop lathe cutting alum bar from 1 inch to 1/2 inch in one pass. In vid I set rollers on od of stock and used a hex turret but could be done on quick change tool post .


http://picasaweb.google.com/jimatcf/BarTurner

Jim Sehr

[Peter.]

Interesting to watch. Is the heavy cut possible because the bar is supported from the rear eliminating flex?

[dvbydt]

Usually the rollers run on the turned diameter. The top roller prevents the material from riding upwards and the other roller controls the size. You get a burnished finish with good new rollers and size control down to 0.001 ins. With tangential tipped tools you can get very close to the maximum use of horsepower of the machine. As an example about 10 seconds to turn 3/4 ins non leaded steel down to 1/2 ins x 1" long at 2 hp and 2000 rpm.
I have not set one up for years - they were a pig to get "just right"

IanR

[jimsehr]

Yes bar turners or box tools can take heavy and long cuts for fast stock
removal. The rollers suport the bar so it does not spring away and vibrate
.
Jim

[TGTool]

Those interested in small machine use may want to know that www.downrivertools.com has nice drawings for a turret for a small lathe and several special tools including the box tool.

[J Tiers]

The machine in the video appears to be an 11" Logan. Not the heaviest machine, although not a lightweight.

Goes to show what good tooling does to improve capability even on a lighter machine.

[EddyCurr]

Maybe some of you might be interested in seeing a home shop lathe
cutting alum bar from 1 inch to 1/2 inch in one pass.

Thank you for sharing, that was eye-opening. Now I am going to search for
more pictures of the tool, following up on TGTool's suggestion to try
DownRiver.

About the swarf. Would tweaking the cutter shape produce more chips,
less ribbon?

.

[oldtiffie]

If you go about it the right way, and if you have rollers on it, your traveling steady - bolted to your carriage - and with a good tool in the tool-post (on your top slide) can do a good job too - not as good as a good box tool in a turret or capstan lathe - but not too bad at all really.

The principle is the same.

[jimsehr]

eddycurr
You can control the ribbon chip by stopping the cut for a second and it will break. But I have seen the ribbon chip come off a hundred foot long on a turret lathe if the machinist wanted to play around.
Jim