Dumb Lathe Question...

I don't have a lathe, and am not sure if I need one yet, and have never used a wood lathe. 35 years ago, I did some work on a metal lathe in a research lab. Here's the dumb question: Why wouldn't I use a metal lathe for wood so I could produce identical cylindars, etc using the screw feeds rather than try and "freehand" the parts and hope they are the same size?

Thanks for any answers.

Rich.....

Reply to
rich
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You can! I a duplicator unit that essentially does that; it has a guide that follows a template and a cutter much like that used on metal lathe.

But, and I hope I don't sound goofy, doing it that way isn't much different than buying it; since it takes no skill, there is no enjoyment in doing it. Maybe that's not important to you, but it is 90% of why I do woodworking.

Reply to
Toller

You could for cylinders. It's hard to use the metal lathe to cut curves (o.e. bowls). There are toolrests (for the 7x12) and you can get a ball turning attachment for a metal lathe. But this takes longer than freehand.

Reply to
Bruce Barnett

Another answer is that when you are cutting metal, you are essentially doing a scraping cut. A scraping cut on wood, especially on spindles requires a LOT of sanding to make presentable.

To get a good wood finish, you have to do a shear (slicing) cut, which I don't think is programmable.

That being said I visited a manufacturer of oboes who turned the very intricate and precise inside of his wood oboes using a metal cutting lathe with a power feed.

Old Guy

Reply to
Old guy

You could, but that would be solving a non-problem.

You misunderstand how "freehand" is done. Lateral reference lines at measured from the end of a spindle to mark the begining, end or middle of a shape. Those reference lines are then cut to a reference depth. From there, it is a simple matter of connecting the dots.

That's how you make four matching table legs "freehand". It is no more "freehand" than a child's "connect the dots" drawing.

Regards,

Steve

Reply to
C & S

Since when? I've been turning metal professionaly for 20 years. The only time I ever use a scraping cut is for large form tools. In other words, seldom.

Reply to
CW

Duplicators work fine. BUT... they essentially scrape the wood, not cut it. No razor sharp cuts when using a wood lathe duplicator. The tear out from these things can be just gawdawful since you are dragging that bit along the profile template.

Making four parts that are exactly the same isn't as easy as connecting dots for me or the others in my club. In fact, one of our challenges was to make fancy, profiled, candle sticks as close to each other in dimension as we could. Two wasn't bad. No one got to four.

But on table legs, that would be different. It is plain spindle turning, and you could put witness marks and depth cuts as needed. It IS similar to connecting the dots in that respect. But the good news is this: If you are off a little, who will know? On our candlesticks we set all of them next to each other and got out calipers to check. YOUR legs will be on four different side of a table.

And if you cut them with a normal gouge, you cut way down (maybe eliminate) tearout and cut down on your sanding. Plus, you're not in for a few hundred dollars for a good duplicating attachment. And it is more fun.

Robert

Reply to
nailshooter41

Metal-cutting tools are slower than wood-cutting tools. It is possible you can use a metal lathe, but the holders, jaws, etc are different.

Reply to
Phisherman

Speed range on most metal lathes is generally from 50 to 1500 RPM. which is generaly too slow for wood turning. I have known people to profile cut cabinet knobs on a metal lathe with success using hard tight grained timbers with no sanding required but thats about a metal lathes limit. For general turning you require a slicing motion. Although it would be possible to set up a chisel in the tool holder to slice for turning cylinders it would be much slower than turning them by hand on a wood lathe. It would not be quite as good a result 'off the chisel' as you could not 'fine tune' the cutting angle for a bit of difficult grain.

Reply to
Paul D

AFAIK - The Oland tool and a metal lathe bit is essentially the same, right?

Reply to
Bruce Barnett

Nope. Takes the same effort to sever the fibers regardless the speed. Makes anything above that mere convenience mixed with danger. It's that MV squared thing. Use your tool properly and 1500 is all you'll ever need. And that's for buffing.

Reply to
George

The nose of a gouge can be used to scrape, too. The Oland looks like a tooling bit, but the turner often uses the edge to shear rather than scrape. Darrell Feltmate is one of the internet-available advocates as you know.

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Problem is that without rigid tool hold and a bevel, things can roll or jump and get away quickly.

Other people shear with their gouges, which gets the bevel into play to steady everything, like this guy.

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Reply to
George

Metal lathes arean't really very good for woodworking. Speeds are wrong, knives are different, etc.. Unless you have money for a lot of tooling, they're harder to use because of the differences between things made of metal and of wood. IFF a metal lathe worked for wood, it'd also be slower and cut rougher in wood.

There ARE some that would work, but they're generally pretty pricey. OH, and more comples to operate and maintain properly.

Pop`

Reply to
Pop`

Thanks for all the input! Gonna have to give this some thought.

I can see where the speed might be a factor, but I think you could grind a tool bit to slice with a little care and design. I agree that inside cuts on a bowl would be tough on a metal lathe, but I'm not fully convinced outside cuts couldn't be done.

As to the artistry of it all, i presently enjoy a dove tail jig for the router, but also enjoy doing them with a saw and chisel. Both have their uses. I can see the art and skill with a wood lathe and a bowl, but also the repeatability and precision of a metal lathe.

Oh, well.... Guess I'll make some more saw dust.

Thanks to all,

Rich.....

P> > I don't have a lathe, and am not sure if I need one yet, and have

Reply to
rich

In that they are both made of steel, yes.

Reply to
CW

No.

Reply to
CW

Yes.

Reply to
CW

No.

Reply to
CW

I've machined steel, aluminum, plastic, phenolic, fiberglass, and wood on a metal lathe. All with good results.

Reply to
CW

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