Dimensions for Tool Rest Parts

[Steve H Graham]

I'm about to make a tool rest for my metal lathe. I have some dumb questions.

The lathe's swing (over the bed) is 16.9", so the center is about 8.5" above the ways. What's a good height range for the top of the T rest (lowest point and highest)?

I haven't made the horizontal piece of steel that will hold the upright doodad the T-rest sits in. How much horizontal range do I want? When I loosen the clamp and move the tool rest back and forth, what would be good extreme positions for the upright thing?

[Steve Peterson]

I have a 12" by 24" wood lathe. I probably move the tool rest height from about 1/2" below center to around 1/2" above center. You might want a slightly larger range if you plan on turning 16" bowls.

My tool rests vary in width between 5" and 12". I sometimes wish I had a slightly narrower tool rest for making pens. I might want a wider tool rest if I was making long spindles. The width depends on what you plan to make.

Steve

[Steve H Graham]

That's very helpful. Thanks. It sounds like I'll be wildly safe if I can go an inch above and below the center.

The T rest width is not a concern to me. What I am thinking of is the sliding bit beneath it, which determines where the base of the T rest is. I would think that if I could move the T rest up and back say 8" (total), I would be covered.

[Geoff Whaling]

Steve,

Is the tool rest for bowls or spindle turning? Do you prefer over hand or under hand grips?

Important points to consider. :) The cross section profile of the tool rest affects spindle turning more so than for bowl turning.

More vertical profiles with a "cove" on the turners face of the rest such as the ones shown at http://www.woodfast.com.au/index.php?p=1_8 allow the turner to use an underhand grip & run their LH (or RH) index finger as a guide, i.e. to follow the tool rest giving more stability and allows the fingers to act as a "depth gauge."

Angled tool rest profiles are more difficult to use for spindle turning as the turners fingers cannot follow the guide and in some cases with "flatter angles" the fingers are well away from where you need tool support so it becomes quite difficult to use underhand grips while spindle turning. These are more suited to bowl turning. http://www.vicmarc.com/default.asp?contentID=727

Similar issues occur with the spindle/detail gouge as the index finger is often used under the tool rest with the thumb "anchoring" and guiding the spindle gouge as it is held between the thumb & index finger (forefinger).

The taper of the bottom of a tool rest may create issues as well. Sharp angles / corners become uncomfortable and the overly large bevels mean you loos support at times as there is not a long enough useable section of the tool rest.

I believe most of the problems turners have with a skew are actually tool rest design problems.

[Steve H Graham]

Uhhh...

Let me get back to you.

[Steve H Graham]

Here's what I got so far.

321675