My new lathe toys...

======>Haephestian fun, eh? Sure you are on the right newsgroup?? I would have thought it might be Promethean fun!*G*

Leif

Nah... Promethean fun would be more on the order of building a boat or having a bonfire. Hammering hot metal is Haephestus's thing. No need to make those poor old Greek gods go get their union stewards! :)

But I figure it's the right newsgroup. Got my first spun bowl done this evening, and it was far more woodturning than anything else (making the mandrel). Not *too* tough, but there are definately more than a few tricks I have yet to learn with it.

A few points of interest for anyone looking to goof around with it:

- Copper will cut nicely with a standard wood blade on a bandsaw when making blanks. (A good use for my little benchtop one, I'd say)

- Skipping the annealing of the blanks is a bad idea- my first attempt has a bit of a crack in the upper edge from not doing that. It's a little goofy looking- smooth and shiny *except* for the one spot where it looks like someone attacked with a pair of tin snips.

-Despite the advice in the spinning tutorials I found, I used my chuck to hold the mandrel, and it worked fine (they suggest faceplate mounting only, but everything I found on the subject was fairly old.)

- Ridges in the bowl will sand out easily, and sanding marks polish out nicely with the buffer- (copper) is almost less sanding than wood, though the sandpaper loads quickly.

- If you're not doing production work (and I'd imagine that'd be most people fooling with it) soft wood works fine for a mandrel. I just turned a bit of willow, waxed it, and went to work. Leaving the tearout alone (as opposed to sanding it all away) didn't seem to affect the finished metal at all.

Should be a nice addition to my turnings in the future- the big bonus for me will be when I get good enough to incorporate the two to make wooden turnings with metal turned over portions of them while they're on the lathe (for bases, caps, etc.) Seems like a good solution for covering faceplate screw holes or less than perfect chuck recesses- or even just to put a contrasting shiny bit on a nice piece.

Now I've got to see how much work wants to let me raid the scrap rack for suitable blank material. Sheet metal is -way- too expensive at the hardware store!

There's a whole lot more to learn if you want to spin metal, I've done some, have a look if you like, scroll down to almost the bottom for copper spun ornament balls.

Nice stuff, Leo- I think those might have been part of what got the idea in my head many months ago in the first place.

Luckily, I have a lot of metal availible to practice on- but do you mind if I pick your brain a little on the subject? It's kind of an obscure subject, and tough to find good info on. Any help shortening the learning curve would be hugely appreciated.

A few of the more obvious things I'm struggling with:

What are the best gauges of various metals to learn to spin with? I have stainless steel, cold-rolled steel, aluminum, brass, and copper available without making a financial investment, but am willing to buy others if I can find them. Practically, 20ga. (.063") is the thinnest stuff that is easy for me to get, but there is occasionally thinner metal that I can get my mitts on. I did try some very thin brass, but it wanted to slide out, and got chewed up very quickly on the mandrel.

What is a good lubricant to use on the metal and the tooling? I've tried paste wax, but it doesn't seem to be up to the task.

Do all metals need to be annealed before spinning, or just certain ones like copper?

Have you tried spinning perforated metals? If so, is it worth the effort?

When using a duck bill profiled tool for roughing into shape, is it better to use the "tip" or the flatter edge? I'm guessing the flatter edge is the thing for finish smoothing, but it doesn't seem to push the disks against the mandrel very well.

I'll get this all figured out eventually, but any guidance you might have would be very welcome- including answers to questions I don't know enough to ask yet, of course!

Cool story and ideas. Thanks!

TomNie

Re spinning different metals:

There are some soft aluminum alloys that spin well and dont really work harden. If I remember correctly the 1000 series and possibly the 3000 series will work well. .063 is a bit thick. Half that thickness or something like 18 gauge (non ferrous) would be a lot easier. When making spinning forms soft wood can work and you can always lock around the form and then burn out the form to recover the spun part. Pewter is a great metal to spin: no work hardening and it polishes easily. Some of the stainless alloys can be spun, but only when heated red hot with a torch while spinning. Not for the fainthearted! Always anneal the copper before spinning. The very light gauges (under .020) are sometimes more difficult to spin. Spinning with a drag tool as you described is not how I learned to do this. I used compound roller tools. Search for James Reiser's web site for a lot of information. He also has a DVD he put together. I think that someone else also made a DVD. Good luck.

Charles Friedman DDS Ventura by the Sea Metal spinner in a former life

Here's some info start with material that is easy to learn with, deadsoft aluminium, or pewter, it does not get work hardened. If you use copper or brass, soften it up before you start and keep re annealing as you workharden it, also your tools should be hard steel and super smooth, Murphy's soap jell works for lubrication, or else get the industrial wax stick for it, I use the back of a hook to roll the metal to the form and keep a back stick to keep the metal up straight, SS is not really for hand forming, can be done with a torch while spinning, but I never attempted that. You do need high pressure to move the metal,(so thinner is better, to a point) and not to high rpm speeds, like 1000 rpm or less. Most banjos wont stay in place while forcing the metal, so C clamps can be used to help it, your aluminium fulcrum pin holder is probably not going to last very long, but you'll find out, I welded a half inch thick bar on a post with holes for half inch hard metal fulcrum pins, stood up for me so far.

Being a turner there should be lots of firewood to use, and I have used a wood fire successfully for heating up metal, a 5 gallon metal can with several 1" holes drilled around it couple of inches from the bottom for air holes, bigger hole in the center for the metal bar to be stuck through, copper or brass sheet can be just placed in the top, you'll be surprised at how well this works. I've got some links here, there are things to be learned from, also a CD or DVD would be very helpful or one on one lessons, there are some books also, I happen to have "Turn a Bowl" by Ernie Conover, and it has several pages on metal spinning in it.

Prometheus wrote:

Thanks Charles!

Ah ha! I was cranking it up to top speed, after reading a few tutorials- maybe that's why it hardens so quickly.

We'll see about the tool post- there's a lot of alumium there, so hopefully it'll hold up for a while, anyhow. My banjo seems to do okay provided I seat it against the tailstock, but I'll keep the c-clamp idea in mind.

Sounds good- I've got some plans in the works to try out the Gingery books for making machine tools, so I'll be making a furnace for melting aluminum soon anyhow. Never hurts to have things doing double duty.

Good deal- thanks Leo!

(Or anyone else who can offer some insight, of course!)

Just a quick question, if you've got time and some info for me-

I've been continuing to practice spinning, but several attempts have ended up making a wavy edge on the outside ring of the metal (where it has not been spun yet, and is still standing up) The mandrel shape I've been using is a "standard" bowl shape similar to a half sphere.

Depending on the material, they either catch the tool and rip up the piece, or lay down and fold over one another when I try to spin them out. Once they're folded, I haven't been able to spin them out.

I'm guessing that this has to do with the way the metal stretches, but judging from the video clips I've seen on this, it's obviously something that doesn't have to happen.

Any clues on what I might be doing to cause this? Pressing too hard? Not hard enough? Not enough working back towards the base? Maybe too much or too little material?

I've got a few things to turn out, but it's still kind of dumb luck at this point- no big "aha" moments yet... I did ask my wife to get me a set of videos on the subject for Christmas, but that's still a month away, and I fully intend to keep playing with it in the meantime!

Don't know what you are using, or what you're doing, but as you force the metal to the form you have to support the backside to keep it upright, and keep straitening the metal by bringing both the forming tool and the back stick out to the edge, if you don't do this the metal will fold and you will have to start over with a new piece of metal, but don,t keep going back and forth to much or you thin the metal to much at the foot. also while moving the metal to the form, support the backside to keep the metal from bulging ,make sure you have enough lubrication, and like with all these things, practice and practice some more. It's not that hard when you know what your doing, but it isn't easy ;--)))

Have fun and take care Leo Van Der Loo

Prometheus wrote:

Maybe that's the problem- I'm not going all the way out to the edge, just forming as I go. It's as good a thing as any to try at this point, anyhow! Thanks for the idea.

Will do- I've been on this like a bulldog, and I'm going to keep after it until I can do it right!