Best Size Bore for Tool Rest?

[Steve H Graham]

I finally got around to machining the tool rest thing for my lathe. Can someone tell me the best size for the bore in one of these things? I notice some posts are 5/8" in diameter and some are 1". I assume 1" is the way to go.

This is not a wood lathe. It's a 16" metal lathe, so the whole project is a little weird.

[John K Jordan]

I finally got around to machining the tool rest thing for my lathe. Can someone tell me the best size for the bore in one of these things? I notice some posts are 5/8" in diameter and some are 1". I assume 1" is the way to go. This is not a wood lathe. It's a 16" metal lathe, so the whole project is a little weird.

Steve, Three of my wood lathes have 1" posts on the tool rests. The other two, Jet mini lathes, have smaller posts. I would definitely want the 1" size if there would be any force on the rest or if elimination of vibration was desired. Unless space constraints would not permit.

JKJ

[Steve H Graham]

Thanks. I will finish the bore now.

[Thom Sturgill]

I agree, I would go for the larger size based on the swing.

[Alan Heffernan]

1" is the standard for the heftier machines.

[Steve H Graham]

Here is what I have so far. Not screwed together yet. Hoping it will work reasonably well.

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[Steve H Graham]

I kind of procrastinated on finishing this thing--for seven months--but today I made a nut that holds the banjo together, and now all I have to do is install a locking lever and get some rests.

Right now, I have to use a 3/4" wrench to tighten and loosen the whole assembly on the lathe bed. If this is a bad idea, someone please speak up. I don't know how hard it is to deal with this while the lathe is running, or whether I should just turn it off every time.

I plan to tap the upper part of the banjo in two places so I can have a lever on the right or at the rear (facing the user). I'm not sure which is best, because I've seen banjos with levers in both locations, so I guess I can't lose if I set it up for both locations.

I am going to look for rests with 1" stems. If anyone has suggestions, fire away. I have no idea what to look for in a tool rest. I would guess hard metals are best so the tools don't scrape and catch.

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[Michael Schneider]

1" is very common and easy to find. My Vicmarc 300 uses a 30mm with is nice as the tool rests are a bit more stout.

At least Robust, Advanced Lathe Tools, and Trent Bosh will do 30mm shaft toolposts. There is also a 30mm to 1" sleeve that you can drop in for 1" tool Posts.

1" is very good, just another option to consider.

Have fun,
Michael

[Dwight Rutherford]

I don't think you can get a better tool rest than those by Robust.

For safety, stop the lathe before adjusting the tool rest.

[Steve H Graham]

I decided to try a 10" Rockler tool rest. It wasn't too expensive. Had to get a bushing to make it fit this banjo, because the rest had a 5/8" stem. I guess we'll see how it works. It will be interesting to put something in the lathe and find out whether I can do this.

It looks like the bore on my banjo is 0.995", not 1". I must have had a reason for doing that, but I can't remember what it was.

[Brice Rogers]

My first lathe (old Craftsman) had a big bolt to tighten the banjo. It was kind of a PITA to tighten and move around - - but it was do-able. I made a dedicated box end wrench for it. My new lathe has a (now standard with most new lathes) lever lock which is easier to use.

You will have to tell us how your banjo works out. It may just be me, but it doesn't seem like it would be as rigid as I would want if it were mine. But, I very well could be wrong and it'll work out fine for you.

With the exception of the single tool post that came with my lathe (which I never seem to use), all of my other tool posts (between a 1/2 dozen to a dozen) are all home made. Some are curved (for bowls), one is a Robust-like comfort rest, one has a 3/4" round bar on top, one is flat and cantilevered for sticking into a hollow-form, etc. With the exception of one, all have the 1" vertical shaft welded to the top. It is pretty easy to make, assuming that you have access to a substantial welder (like a moderate amperage AC stick welder, or very big wire-feed - - the little inexpensive wire feed welders won't work very well). But on one of the tool posts, I machined it on a metal lathe and the parts fit together with a very thin gap (maybe a couple of thousandths). So, the parts fit together fairly tightly. On that one, I silver-soldered it. If you don't have a welder, this may be a reasonable option for you. For closely fitting machined parts, the silver solder has wayyyy more strength than you might imagine. If you want advice on silver soldering (which is lower temp than welding) send me a PM and I'll share some hints.

Having a hardened steel tool rest is nice and preferred by most turners. But it complicates making your own. None of mine are hardened. But, it has been close to a year since I last needed to use a file to dress a rest and it only took a minute. At the rate that I'm filing the rests, they'll eventually need to be repaired or replaced - - but I calculate that it'll be required in about 300 to 500 years. :D But it depends on the frequency of your major "catches". I don't have very many catches any more.

[John K Jordan]

... 1" vertical shaft welded to the top. It is pretty easy to make, assuming that you have access to a substantial welder (like a moderate amperage AC stick welder, or very big wire-feed - - the little inexpensive wire feed welders won't work very well). ... I silver-soldered it. If you don't have a welder, this may be a reasonable option for you. For closely fitting machined parts, the silver solder has wayyyy more strength than you might imagine. ...

I had only a small 110v wire welder for years. I wouldn't use it for pressurized or heavy things that life depended on, but by grinding deep bevels and welding multiple passes I welded some surprisingly heavy pieces. The problem, of course, is getting sufficient penetration into both pieces. (I was a welding inspector once) For something like a tool rest I'm imagining the strength would be more than sufficient but a test piece and a hydraulic press and sledge hammer could prove it.

One of my welding books illustrated the strength of brazing with tensile tests on steel bars. The steel deformed before the joint failed. I see the tensile strength of sliver braze alloys is 40,000-70,000 psi. (The Harris Products Group). These days I keep oxy-acety tanks just for brazing/silver soldering. The oxygen lasts a LOT longer since I quit using it for cutting!

JKJ

[Steve H Graham]

You will have to tell us how your banjo works out. It may just be me, but it doesn't seem like it would be as rigid as I would want if it were mine. But, I very well could be wrong and it'll work out fine for you.

I can't move it forward or backward at all. If I push sideways on it, it will lean maybe 1/8"-3/16". I haven't been able to check a factory banjo against it, so I'll just have to try it and see.

If the angle iron turns out to be a problem, I can replace it with milled aluminum or a heavier piece of angle iron.

[Steve H Graham]

The remaining parts for the banjo arrived. I put a threaded hole in the banjo, put the rest in the bore, and tightened everything up. Here it is.

The wood chuck is held in my 3-jaw metal chuck. It appears to be in there solidly. I guess I'll find out.

I still need some kind of dust collection. I am thinking maybe I could rest a rectangular dust hood between the bed ways, face up. I don't have a proper dust collector. Just a shop vac.

Anyway, I can see this will work. I don't think it wobbles enough to be a problem, but if I'm wrong, I can fix it by redoing the flat part with heavier angle iron. I pushed on it just now to see what it does, and it appears I can only move the rest about 1/8" to the right or left at the top.

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