Where does "turning" end and "machining" begin?

It would not be unreasonable, I think, to conclude that there never was a distinction that went any deeper than the typical materials each dealt in and the amount of math involved. It takes a LOT of trig to describe the shape of a baseball bat, bowl or pen. And that stuff by Bin Pho and his merry band with all its little cutouts and open-ended arcs? Puleeeeze!

Volutes and involutes, tangents, FIM, TIR, concentricity, runout ... the list could probably go on for pages. Yup, we could muck things up proper if we half put our hearts into it.

In fact, we could muck it up enough that a 7th grader would never again pick up a scraper and a block of cast-off wood to give it a try.

I've been away from that rarified world that machinists and tool & die makers live in for so long that I'm not even sure if I could speak the lingo anymore, much less do the math and make the part coming out the other end of the die look like the drawing says it's supposed to look like.

But I can still make shavings. Made some nice ones today. Tomorrow, God willing, I'll finish up a desk set from awesomely curly koa. The only math I did was to calculate a setback from one end because the drawing was wrongly dimensioned. (It showed how much wood to leave when the actual important issue was how much tube to expose. Bad dimensioning ... so I guess I DO remember a LITTLE something from the machine shops.)

Tomorrow I'll do a little more math ... I'll figure out how much money it's going to take to get me to part company with the set.

Bill

To me, people tend to think of woodturning as more free form artistic endeavors than other aspects of woodwork.

I would submit that this is because the end results of a typical turning project don't have to serve any other function than to be pleasing to the eye. Most projects aren't drawn out beforehand, carefully laid out on the wood, and certainly don't adhere to strict dimensions as a mark of a successful piece.

Nope. I think most chuck up a piece of wood with a general design in mind, and start cutting.

To further the confusion, I think some mistake the fact that they are manipulating the cutter in their hands as a totally different operation than holding the material like you would with table saw. Apparently there is a harmonic flow that eminates from the wood when you become one with it.

Sadly, most of the demos that I have enjoyed have been from turners that took the "gimme just a minute while I hog this off" approach. It sure takes the airy approach of an artistic turner in another direction.

If we call an operator of a metal lathe a machinist, why do we call woodturners something different? Probably so we can be charged more for our tools (my ears are still ringing from the newest price increases from Craft Supplies and Packard). Think about it; both spin the material to be shaped or cut. Both can be operated manually or semi autonomously, and in both cases the cutter/scraper/finishing tools approach the material. So the only difference to me is for the most part one holds the tool when woodturning (unless using a duplicator or one of those monster hollowing rigs) and in the other the machine holds the cutter, placed and directed by the operator.

I think it is >>all

Maybe its what's between you, the tool that does the cutting, and the wood - as well as the precision required. Trying to cut a curve with a cutter in an XY cutter table is tough

- Etch-A-Sketch type thing. Maybe it's having the tactile feed back that a hand held cutting tool provides.

Then there's CNC machines - no tactile feed back but curves are no problem - not much fun either.

But back to routering in flutes, spirals and the like. Are you actually turning with a Legacy machine - or machining?

There's a similar issue with dovetails. Handcut and you have an infinite range of possibilities. With a router and jig you have a limited number of possibilities. And when you handcut them you can make the pins smaller than any affordable machine/jig combo can make.

Maybe it's a practicality thing. Use whatever you've got to get close to where you want to be - then do the part that requires the finesse turning that's best done by hand.

As for Bin Pho - he's one of those guys that uses turning as a part of the art he creates - one medium as a part of a greater whole. His stuff "speaks" to me and I like what I hear. Others may have completely different opinions of course.

Turning sure has gone in a lot of different directions - most in an interesting and good direction. Room for everyone!

charlie b

Hello Charlie, my boring tool is about as machined as your would fancy. the only element that keeps it in the "creative range" and away from automation is the fact that you have to feed the tool in and out, and manually place the direction and depth at your finger tips.

I have had some coments about my boring system as taking all the creativity out of boring, but to me it takes enough extreme dexterity to draw sweat out of me even on cold days.

cad

Some would argue that when you're machining something on a metal lathe, you're turning.

Seriously, though- there is one thing here that you're missing, which I have lately been reminded of when spending a lot of time on the knee mill making my little metal lathe. While you're correct that there is no tactile feedback from a CNC machine, the argument simply doesn't hold up when you're talking about a manual metalworking machine. Rather than holding a handle, you are turning cranks, but the vibration is transmitted through the handles, the feed has greater or lesser resistance, cuts can climb and jerk the table around if you feed in the wrong direction, etc.

It's also interesting to note that you can turn steel with a handheld graver much the same as you can turn a wooden blank with a gouge. The differences are in how the tool is made and ground, and in the fact that metal peels while wood shears.

Now, there's also nothing wrong with routing spirals and grooves. There seems to be a big hangup about machining (and I confess that I've occasionally trapped myself into defending the "everything freehand" position) that probably should not be there. The biggest difference that I can tell, and the one that always seems to get my goat is that wood simply cannot be held to the same tolerances as metal or plastic. A guy can mill or turn something perfectly to begin with, but there is always swelling and contraction with changes in humidity and temperature, and if you're having a bad day, cracking and distortion to boot. When you run any machine, you're machining. I don't cut freehand on my table saw- I use the fence, miter gauge or a jig.

If you're concerned about the routed spirals lacking something because you used a jig to keep them even, there is always room to embellish them after roughing them in- and that can be done by hand. We don't have the same workholding, material feed systems and degree of precision in woodworking as there is in a metalworking shop because it simply is not needed- wood is soft compared to a hunk of steel, and it's not nearly as likely to catch on a drill bit or mill and tear out of your hands. They're just geared towards different materials.

And beyond that, there is the question of commerical woodworking- if you've ever been in a modern cabinet shop or furniture manufactuer, you'll see the same types of machines you'd expect to find in a metal shop. CNC isn't limited to metal- it's just simply beyond the financial reach of most people who don't require it to make a living.

Bingo! I've been making a lot of custom carved pistol grips lately, and the fine tuning is done with hand tools- but to rough them into shape, I favor a pnuematic die-grinder with a 40 or 60 grit sanding disk. It's not a matter of skill with the chisels- it's a matter of doing the job efficiently enough to actually turn a profit on the things. Rather than spending time searching for the carving gouge with just the right profile to pare away the inside of a concave curved surface, I can use one tool that stays in my hand, does not require sharpening, and will leave a surface that makes sanding and hand-tuning that much easier.

It seems to me, the line is thick enough.

Turning: You rotate the workpiece past a stationary or moving tool.

Machining: You rotate or/and move the tool past a stationary workpiece.

Other ideas?

BjarteR

Machining: To cut, shape, or finish by machine. There is no distinction as to material, tool type or process. You machine something on your lathe (wood) using hand held tools. I machine something on my lathe (metal, plastic) using machine held cutting tools. You machine something with a router. I machine something with a milling machine. Same thing.