Carbide Tool Question

[James Baldwin]

Hi, I just picked up a set of carbide tools. A 16mm round, 12mm square, and a diamond. I also got a set of replacement cutters (inserts). The replacement cutters contained 12mm round insert which I didn't have shaft for so I decided to build a shaft. I used 1/2 inch square CRS. Worked good. So then I decided to make one for hollowing not true hollowing but to clean the insides of bowls with a slight hollow. I have a couple of Solby gooseneck hollowers. So here's what I did drilled and tapped the square stock then bent it at a 45* angle 2 1/4" from the end. I've seen tools online wit a bend in the end so I was trying copying one. When I tried it it wanted to catch. Tried several things no joy. Finally straighten it out and will use it a straight cutter. My lathe is a Jet 1236 and doesn't reverse. I was standing facing it with the headstock to my left. Would it make a difference if I was standing on the back side (headstock on my right)? Jim

[Brice Rogers]

James, I think that all manufactured hollowing tools make sure that the cutter is lined up with the central axis of the tool. That way there won't be any twisting or torsional forces.

Imagine if you had a tool with a cutter two or three feet to the left of the shaft. Would the forces make the tool twist counter clockwise? Absolutely.

So, curve the tool to use as a hollower but keep the cutter in line with the axis of the tool and when putting it on your tool rest make sure that the straight portion is on the tool rest and NOT the curved portion.

[David Walser]

James -- Brice gave you good advice. I'm chiming in to suggest you don't need nor should you want a swan's neck shafted tool for hollowing a bowl or any other mostly open shape. Curved hollowing tools are used to hollow underneath the lip of a fairly closed form, such as a vase with a small mouth. They are curved to reach where a straight-shafted tool could not. Other than those situations, I think you'll find you can hollow anywhere you can reach with a straight-shafted tool and have better control than you would with a swan's neck shafted tool.

[James Baldwin]

Thanks for the information. I'm probably going to try standing on the back side of my lathe for some things as it would put me in a better position for somethings plus I could see what I'm doing better. Jim

[Sam Force]

I don't have that lathe, nor have I used 1. But standing on the backside sounds unsafe to me. How would you stop the lathe in an emergency? Reaching across a spinning chunk of wood to shut it off sounds dangerous to me.

[John K Jordan]

Thanks for the information. I'm probably going to try standing on the back side of my lathe for some things as it would put me in a better position for somethings plus I could see what I'm doing better. Jim


If your lathe will run in reverse that’s another option to continue to work from the front. I sometimes operate my lathe in reverse when shaping the inside of certain things. Heavy pieces may need a set screw tightened to keep the chuck from loosening if you sometimes get catches but otherwise it’s not needed.

Another option for safety in case of panic is to wire up an emergency off switch that you can place anywhere. My lathe has one on a long cord with a magnet to hold it where desired.

Some lathes even have positionable controls which wouldn’t be impossible to add to a lathe with a VFD that uses a low voltage control system.

JKJ

[David Walser]

Since your Jet 1236 does not reverse, if you want to be able to see the cutter as you're cutting, you'll need to stand on the other side of the lathe. (For those of you unfamiliar with the Jet 1236, it's a Reeves drive lathe.) As others have pointed out, standing on the 'wrong side' of the lathe makes it more difficult to reach the on/off switch. However, it's not too hard to reach around the far end of the headstock to turn the lathe off when standing on that side, or you can just unplug the lathe from the wall. What's more inconvenient is changing speeds. There's no easy way to do that from the far side of the lathe.

With the 1236, you shouldn't be hollowing anything too large or too deep. The lowest speed is about 600 rpm, which is too fast for a large out-of-balance blank. And, the lathe doesn't have enough mass to handle large work, anyway. In my mind, it's a good lathe for spindles and smaller items, like boxes. I have the HF clone of the Jet 1236. I've hollowed lots of smallish items on it. I've never felt the need to stand on the far side. YMMV.