So what's this thing?

twstoerzinger

twstoerzinger

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This came in a box of cutters and tooling with at lathe that I bought.
It has two brazed-on carbide cutters. They both face the same direction, i.e. it does not cut in a rotary direction.
The two halvs are clamped together by a small SHCS and there is a small screw to use as a jack bolt.
There is lettering on one side that says "Madison Rougher (Pat Pend)."
All of this stuff came out of a small tool and die shop. It could be that this is not a lathe tool at all.
It looks to be unused.
Thanks,
Terry S.
IMG_1829.JPG

IMG_1829.JPG
 
Its an adjustable boring bar for use with a matching holder. G&L still makes them with insert tooling. They're called Davis bars.
 
Ghoulardi,
Thanks for the response. I have seen double sided boring bars before. I think they are sometimes called "balanced load" bars.
What has me going on the photo below is that both cutting edges are on the same side of the bar. On double sided boring bars, one cutter faces one way and the other faces the opposite direction so that both cut when the work piece revolves about them.
On the tool below, if you try to bore with both sides in contact, one of the cutters will be dragged backwards in the bore.
I will have to look at it closer. Maybe it's assembled wrong.
Terry S.
 
OK - now I see how it works.
I had it in my head that axis of rotation was parallel to the slot you can see milled in the surface.
If the axis of rotation is perpendicular to the milled slot, then both cutters will bore at the same time.
I take it that there is some type of clamp on the boring bar to hold the cutter assembly.
I'll go through all of the parts again and see if the mounting bar came with it.
Terry S.
 
Is there a recess for the setscrew head on the other side of the holder too? If so, perhaps the idea is to use one side 'till it's dull, then flip the holder and use the other side. The slotted area for the setscrew tells me this tool isn't intended for cutting with both sides at once. The word "rougher" and the rather substantial looking carbide thickness lead me to think this.
 
L Larson,
The two halves of the cutter are not identical. The upper part (as appears in the photo), has an elongated counter-bore to accept the socket head cap screw.
The lower part is tapped to accept the cap screw. The lower part has an extension to the top which mounts the set screw (used as a jack screw). The upper part has a notch to fit the jack screw extension. The distance between cutter ends is adjustable from about 1.30 to 1.50 inches.

It appears that the design is intended to achieve a fine adjustment of the distance from outside to outside of the cutters.
The milled recess visible in the front of the photo becomes offset as you adjust the distance from cutter to cutter.

I think some of the other responses have it right when they say it is part of a double cutter boring tool.

Terry S.
 
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