What is Proper Tool Rest Clamp Height Relative to Spindle?

[ELY WALTON]

I apologize if this has been covered in another thread. Just noticed the big differences in the tool rest clamp heights relative to the spindles. That is, on some lathes with the tool rest centered on the spindle, there is a lot of the tool post exposed. On others, there is a minimal exposure -- the tool post clamp is higher.

Just wondering if there is an advantage to having a lower post clamp? I would expect that if a "thicker" tool rest (e.g., Robust style comfort rest) can be set to be just a bit below the spindle centerline or higher, that is all that is needed. Or is there a purpose to being able to set the rest much lower than the spindle?

Sorry to ramble -- hope this makes sense.... Thanks!

Ely

[Thom Sturgill]

When turning bowls a 45,45,45 position is often used (45degees out of plum toward the tailstock, 45 out to the front, and 45 rotation to the wood, see Bill Grumbine's excellent videos). This requires that the tool rest be much lower than typically used for spindle work. You want the cutting tip to be at or just above center for most work, though some use a skew much higher.

[Scott Ticknor]

Thom gives some excellent starting points. Over time you will experiment and find what works for you. Try not to be constrained by cast in stone angles or heights .Start from the variables mentioned , Focus on the cut and adapt to suit your personal style .

[Roger Chandler]

Spindle turning, you want the tool rest a little higher, especially when using the skew. Bowls a little below center to allow your gouge to cut at center line. Shear cuts with the wing, [not scraping] I lower the rest a bit, and drop the handle low, and this can give you the best surface off the gouge and in some woods eliminate much tearout, and sanding with lower grits.

[Reed Gray]

It kind of depends on how you hold your tools. I tend to hold mine more level, so I would want the tool rest at or near center height. If you hold your tools with a dropped handle, then you would probably want the tool rest a bit lower. Kind of a figure what is comfortable for you and adjust the height to suit your style...

robo hippy

[ELY WALTON]

Got it. Thanks for all the great inputs!!

Ely

[John K Jordan]

...Just wondering if there is an advantage to having a lower post clamp? ...is there a purpose to being able to set the rest much lower than the spindle?
Ely

I have several lathes, different sizes and with different banjos and clamp heights. I never gave the clamp height any thought and can't see how it will matter much. I often put the top of the rest a little below center but not "much" lower, whatever that is. A tool post with more exposed might be marginally less supported but I doubt that would matter with most lathes with cast iron banjos and 1" thick tool posts.

I think the position the top of the rest relative to the spindle centerline depends on several things, such as:

The type of tool (skew, scraper, spindle gouge, Hunter carbide, parting, bedan, etc...)
The thickness and design of the tool (dist from bottom to cutting edge).
How close the tool rest is to the work.
The height of the lathe and the height of the turner's arms.
How you hold that tool.
To some extent the grind on the tool, e.g. the bevel angle on a skew.
Perhaps the diameter of the spindle.

When turning spindles, especially thin spindles I often adjust my tool rest a tiny bit, maybe a millimeter, to get it "just right." I might even change it a some when holding the tool a different way for different purposes, for example when I switch from holding the tool in two hands to holding it in one and supporting the work with the other hand, especially (as Thom mentioned) for planing cuts with the skew. I think it boils down to what works best for you with experience. I'd recommend trying different heights to see how they feel, moving the rest only a very small distance each time.

JKJ

[Joe Bradshaw]

I use the pointer finger on my left hand to set the toolrest height. I wrap my finger around the toolrest post and lower the tool rest untilit rests on my finger. This method only works on one of my lathes. For the rest, I adjust the toolrest to just slip under the threaded portion of my live center. This usually gets me in the ballpark and I can adjust further from that point. It all boils down to what works for you.
Joe

[Joe Meirhaeghe]

I guess I'm the odd man out here but I do a lot of my turning with the handle pretty low which in turn translates to the tool rest being much lower than most people use. Many times I''ll have the rest 1" or more below the center line.
I think a lot just has to do with the angle you grind your tools to & your personal turning style. I've only turned on a Jet the 1642 a few times but I found the tool rest didn't go low enough for me to be comfortable with the way I like to turn. I liked most everything else about the jet except the bandjo.

[Leo Van Der Loo]

I would say it depends on the tool rests that you use, a high toolrest plus the amount you like your rest to be set at, I like Joe above here hold my tools on a sharp-up handle and so the banjo post has to be low enough to accomodate that.

Then the toolrest should also be able to go a bit above center height for those times you use a scraper, here is a picture that shows how steep I might hold my bowl gouge when turning on the outboard side of my lathe.

The picture was taken to show how I was holding my gouge, normally my left hand would be up on the toolrest, but this shows it better.

turning.jpg

[John K Jordan]

The wood certainly doesn't care how high the tool rest is. The cutting action of the tool is identical in all of these positions:

toolrest_all.jpg
(BTW, When I posted this 12 years ago in a discussion about tool rest height on another forum one person became upset. Evidently only his way of thinking was valid.)

The difference is mostly in control. Some factors are the height of the turner and the lathe, how high your arms are and how you like to hold the tool, what is a comfortable position for the hands, how much you bend your arms, if your elbows are unsupported or well supported against your side or hip, and how you move your body. The illustration shows some extremes - in practice holding your arms and elbows very high or very low might be quite uncomfortable! Most people find it more comfortable and more controllable to use a certain height which often turns out to put the rest at about the center line of the spindle.

Note that some positions may be more appropriate for some times of turning - turning a spindle 2" long and 1/8" in diameter might require a different method of support than turning a 20" platter or bowl.

There is some effect due to gravity but that's insignificant. IMO, the biggest issue, besides the all-important arm/hand position, is as the rest is move higher the post may run into the work and keep you from positioning the rest close enough to the wood.

JKJ

[Michael Mills]

What the others said about tool rest height in relation to the work.
But your question.."That is, on some lathes with the tool rest centered on the spindle, there is a lot of the tool post exposed....
That varies by maker. With the top of the rest at center height.. On my Nova there is about 2" exposed, on some PM's maybe only about 3/4", per someone with a Grizzly it is so short the rest can't be lowered even 1/2"

[ELY WALTON]

What the others said about tool rest height in relation to the work.
But your question.."That is, on some lathes with the tool rest centered on the spindle, there is a lot of the tool post exposed....
That varies by maker. With the top of the rest at center height.. On my Nova there is about 2" exposed, on some PM's maybe only about 3/4", per someone with a Grizzly it is so short the rest can't be lowered even 1/2"

Thanks for summing up, Michael. Yes, what I am taking away is that a banjo/tool clamp that does not allow the rest to be at least a couple of inches below the centerline will restrict how some like to position their tools....

But as JKJ said, "(BTW, When I posted this 12 years ago in a discussion about tool rest height on another forum one person became upset. Evidently only his way of thinking was valid.)," reasonable turners may disagree!

Thanks again to all for the replies!

Ely

[Dane Riley]

The wood certainly doesn't care how high the tool rest is. The cutting action of the tool is identical in all of these positions:

toolrest_all.jpg


The difference is mostly in control. Some factors are the height of the turner and the lathe, how high your arms are and how you like to hold the tool, what is a comfortable position for the hands, how much you bend your arms, if your elbows are unsupported or well supported against your side or hip, and how you move your body. The illustration shows some extremes - in practice holding your arms and elbows very high or very low might be quite uncomfortable! Most people find it more comfortable and more controllable to use a certain height which often turns out to put the rest at about the center line of the spindle.



JKJ

This also relates to the thread on lathe height. If you are short just lower the tool rest (assuming you can) and it is all the same. Much easier than shorting the legs or building a platform. It does mean tool position will require a bit more thought, and you will never hold a tool level (scrapers may be the exception).