Metalwork on wood lathe

I suspect many existing members of this group will have an apoplexy reading this but I shall ask anyway: Has anyone done metalwork on a wood lathe?
The reasons to ask are convoluted: I can see some use for wood lathe here in its proper capacity. My wife wants to turn wood. The space is limited. Money is limited. There is a very good wood lathe (General) on sale locally for $569. It would just about fit into the available space. The lowest speed is 300 rpm with a 3/4 HP motor.
I understand that not having a cross and compound slide with tool holder is an issue. Still, having seen some of the Heath Robinson arrangements around I thought somebody had to have tried it and wondered what kind of work they had success with.
--
Michael Koblic,
Campbell River, BC
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Michael,
The other way "round is usually the most common. It is far easier to do wood on a metal lathe without harming anything than it is to do metal on a wood lathe.
The lathe I bought had, for years, been used for wood turning, in a kind-of unusuall fashion. The guy had it rigged as a kind of tracer, with 1/8" metal patterns fastened to a bracket on the bed, behind the ways. He had taken the feed-screw out of the compound, and simply put a HSS tool in, and hand-fed the compound while the lead-screw advanced the carriage, and he turned spindles for his rocking chairs. Neat work. He even had extended the bed with some CRS flats to get another 14" length for the tailstock. And it works.
Flash
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There have been some reprints of lathe books old enough to describe the manual turning methods in the Lindsay catalog, http://www.lindsaybks.com but I don't see any current ones that I have a copy of and can recommend. - - - I've just gone over 25 pages of the hand-turning section of Holtzapffel Book 4 and am more confused than when I started. It's similar to turning hardwood but the cuts are much shallower and the speed reduced. I think you could make a pointed graver (chisel) by grinding a bevel on the end of an old triangular file or hex key and mounting it in a long handle. Apparently you make shallow circular cuts by pivoting the tool on the rest because it's difficult to slide it along the way you can with wood. He suggests that you can't remove very much off the diameter and are better off using a cold chisel or forging down smaller sections.
You might be able to carve a brass, pewter or aluminum gnomon on the wood lathe with gravers and files. I remember aluminum as being fairly easy to turn on my father's Shopsmith wood lathe.
I mentioned a wood lathe earlier as a way to polish the disks, especially if you can mount a faceplate on the unobstructed left end of the spindle, like for turning large bowls. It's probably a waste of effort to attempt to make machine shafts and such on it, except for drilling centered holes in bushings.
My $500 would wait for a used 9" - 12" metal lathe that can cut threads. They turn wood nicely using the chuck and a metal band around the wood at the tailstock to keep it from splitting, if you can't find spur and cup centers.
Jim Wilkins
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On Tue, 21 Oct 2008 17:41:44 -0700, "Michael Koblic"

Brass and Aluminium can be turned freehand. Steel would require a light touch. Gerry :-)} London, Canada
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The solution of course, is to buy the metal lathe and use it to make a wood turning lathe!
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On Tue, 21 Oct 2008 17:41:44 -0700, "Michael Koblic"

I have worked aluminum on a Shopsmith lathe before. I needed to make bearing races for a camera pan unit I was building so I mounted the piece on the spindle and clamped the cutting tool to the table saw table. This gave me verticle adjustment. I clamped the tool where the cut needed to be and used the quill for depth control. Worked rather nicely.
Jim
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Don't take that to mean a Shopsmith is good for general metalworking, the saw table especially is much too flexible on its skinny little mounting poles and its lift mechanism is fragile.
I do think the horizontal boring machine design of them has potential for a bootstrapped homebrew lathe/mill. I've written up suggestions on making such a machine from welded angle, tubing and pillow blocks here before, with apparently no takers. The basis is the Lincoln miller of ~1850. If you want to build a machine tool with hand tools, the first successful ones have some good ideas to copy.
Jim Wilkins
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Don't take that to mean a Shopsmith is good for general metalworking, the saw table especially is much too flexible on its skinny little mounting poles and its lift mechanism is fragile.
I do think the horizontal boring machine design of them has potential for a bootstrapped homebrew lathe/mill. I've written up suggestions on making such a machine from welded angle, tubing and pillow blocks here before, with apparently no takers. The basis is the Lincoln miller of ~1850. If you want to build a machine tool with hand tools, the first successful ones have some good ideas to copy.
***This is one of the issues I am grappling with. When I ask myself: "What are you going to use the lathe for?" the first twenty or so answers are "build another lathe".
There are some nice descriptions of home-made lathes on the net. The crucial thing seems to be the headstock: Once you have something that turns a faceplate many good things follow from that and the machine can be extended with the use of this facility (I am being very general here and ignoring such things as ways etc.).
There are quite a few headstocks on sale on eBay. However, it seems somewhat insane to spend $200 on a headstock only when I can have a very decent wood lathe for $569.
I think all those who say it is better to go with the metal lathe and do woodwork on that have a valid point. However, the economics do not favour it: The cost of a useful metal lathe is $1000 give or take a few. I would not mind one of the mini-lathes but they are no cheaper. Those that are cheaper are either "short" (Busy Bee 7x8), or have small motors with limited speed control (House of Tools, 7x12).
The way I thought about it is I could make various round metal plates with more control than I have now, I could make central drilling much easier (although since I made a center-drilling jig for my drill press things are much more civilized) and I could make wooden parts for various contraptions with less effort (and probably more accurately and safely than what I am doing now on the drill press).
OTOH tomorrow I shall go scavenging - if I remember correctly the local scrap yard had bins with bearings, shafts and all kind of other interesting articles. Maybe that is the way to go after all.
--
Michael Koblic,
Campbell River, BC
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I suggest buying pillow blocks and shafting new, so you get known-good ones and perhaps more importantly so you find a supplier who can sell you more stuff of the same sizes later when you want to expand.
The Lincoln miller was meant for production and it's not convenient to set up, but it's design is simple enough to copy in wood or weld from scrap steel;
http://www.sperdvac.org/Horizontal%20Mill/milling_machine_lincoln.jpg
I'd add a second tailstock column to make it serve as a lathe and bolt the pillow blocks to the uprights, which could be well-braced steel angle, channel or strut, or just wooden posts. The work table would be an X-Y table or vise bolted to the horizontal base and tweaked into alignment with the spindle, thus it has no long precise bearing surfaces to make. The vertical spindle feed would be nice to add later for milling. My sawmill has one like it with bicycle chain connecting the screws.
You would align all four bearings with a piece of drill rod, then substitute keyed shafting for the lathe spindle or milling arbor. Find the large drive pulley first and buy keyed shaft and bearings to fit it. 1" is common around here for large pulleys and it's also a standard milling cutter center hole size.
Once the basic machine works you can use it to improve itself. After you grow tired of it and buy real machines it can be dismantled to save space and reanimated for odd, oversided jobs that don't fit a smaller machine.
Jim Wilkins
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