tool rest height

[Brian Deakin]

It is my understanding that the correct tool rest height for a bowl or spindle gouge is about 1/8 inch below centre so the tool is cutting on or slightly above centre


The height of the tool rest is adjusted up or down dependant on the thickness of the tool so in effect the tip of the tool cuts on or slightly above centre


The reason for my question


Recently I have seen a number of new turners set the tool rest set about 1/2 to 1" inch below centre and angle the tool upwards


Can anyone please comment/advise as my understanding is setting the tool rest at this lower height is not a good approach

[mike calabrese]

There is tons of info on your question on you tube
here is one such video this guy explains really clearly and he is prolific with all turning videos.
https://www.youtube.com/watch?v=9Ew0Xj8hTaw&t=399s
and a few more here https://www.youtube.com/results?sear...ol+rest+height
calabrese55

[Edward Weber]

Tool rest height is irrelevant to a degree.
What you want, is for your tool (whatever it may be) to cut, where you want it too.
Too many times people discuss this as if all our tools were used perfectly flat and level, this is not the case.
If I'm using the wing of my bowl gouge to shear accross the outside of a bowl, the rest is set very low because of the high angle of the tool. The cutting edge is actually above center.

Long story short, the tool being used and the type of cut you want determine where the tool rest should be.

[Reed Gray]

For me, most of the time, I hold my tools fairly level. This means that my tool rest is at or slightly below center. Many prefer when doing spindles to have the tool rest slightly above center. The reason some angle the tool up, especially with bowl turning, is to get a higher sheer angle, and this cut is more popular with the swept back grind gouges. The higher the sheer angle, generally, the cleaner the cut. This particular cut is done by using the wing of the gouge rather than the nose. I use scrapers for my heavy roughing cuts on bowls. On the outside, you want to be at or slightly below center. On the inside, you want to cut at or slightly above center. So, for these cuts, I generally raise the handle or lower it a bit. Of course, I hope you know, that if you ask 10 different turners the same question, you will get at least a dozen different answers....

robo hippy

[roger wiegand]

Adjust the tool rest so that it allows you to comfortably present your edge to the wood at the angle you want. That's going to vary with the tool type, the diameter of the piece, the bevel angle on the tool, how tall you and your lathe are, and probably multiple other factors. Setting up a coring or hollowing jig is one of the few times when I actually pay attention to exactly where the tool is relative to the center; the rest of the time if I can't easily get the tool where I want it to be I move the rest, no matter the height relative to the center. This is one of those areas where I'd do what works rather than what some youtube video says to do-- you can tell if your tool presentation is off or if you're having to contort your body to get the tool to work correctly.

The experiment is trivial-- move the rest one way, if your cut is harder/worse, then move it the other way. If it's better, then try going a little farther in the same direction. When it gets worse again back off a little and you will have found your optimum. It's just like finding the best speed for a particular situation.

[Edward Weber]

Adjust the tool rest so that it allows you to comfortably present your edge to the wood at the angle you want. That's going to vary with the tool type, the diameter of the piece, the bevel angle on the tool, how tall you and your lathe are, and probably multiple other factors. Setting up a coring or hollowing jig is one of the few times when I actually pay attention to exactly where the tool is relative to the center; the rest of the time if I can't easily get the tool where I want it to be I move the rest, no matter the height relative to the center. This is one of those areas where I'd do what works rather than what some youtube video says to do-- you can tell if your tool presentation is off or if you're having to contort your body to get the tool to work correctly.

The experiment is trivial-- move the rest one way, if your cut is harder/worse, then move it the other way. If it's better, then try going a little farther in the same direction. When it gets worse again back off a little and you will have found your optimum. It's just like finding the best speed for a particular situation.

Well said, I agree 100%

[Bill Howatt]

No argument with most of what has been said but a tool rest too low (whatever that is, and it depends on the workpiece diameter) will make a catch worse by drawing the tool under the piece and essentially pinning it with the tool rest.

[Edward Weber]

No argument with most of what has been said but a tool rest too low (whatever that is, and it depends on the workpiece diameter) will make a catch worse by drawing the tool under the piece and essentially pinning it with the tool rest.

The tool rest height does not totally determine cutting height. Tool angle has a significant input.
Centerline is centerline, regardless of diameter.

[Bill Howatt]

The tool rest height does not totally determine cutting height. Tool angle has a significant input.
Centerline is centerline, regardless of diameter.

Tool rest too low as in allowing cutting edge too low. A 1/16 cutting edge too low on a 18" dia piece is less of a problem than 1/16 on a 6" piece.