When working with a spring pole lathe, do you have to use green wood or can regular kiln dried lumber work as well?
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Replies
Hi M ,
I don't know how it would matter to the lathe , really the mechanics and system is no different for green as kd lumber. A lathe that only turned green would limit it's uses imo .
regards dusty
Hey dusty,
Yeah, I wasn't sure if the torque created from a spring pole lathe would be strong enough to effectively turn kiln dried lumber. I figured since the wood was dry, the wood fibers would be tougher to cut and you would need something with a little more power to sheer the wood. Every time I see someone using one they're usually turning green wood. I'd like to make one but my supply of green wood is zilch unless I cut down a tree, and from where I have no idea.
mike
Hey mvflaim,Check craigslist in your area for green wood. Lots of times folks will put a listing in the free section for "Free Wood" or some such announcement. Usually a tree is blown down in their yard and all you have to do is go and get it.Of course you will probably need a chainsaw, maybe a trailer. Anyway, free wood is all around. Just need to seek it out (if you want it).J.P.
J P thanks for the tip. That's a great idea!
Mike,
This is a subject I was interested in some years ago. I saw a design not for a spring pole lathe exactly, but for one with a chain drive from a bicycle's rear cluster (cassette) of gears. The racheting mechanism in the gear cassette enabled the lathe spindle to keep turning in one direction, rather than reversing direction each time the foot treadle came up, as I think a spring pole lathe does. Please correct me if I'm wrong about this.
The bike gear lathe used a foot treadle and had a return spring as well. I seem to recall the chain looped over the gears and returned down to the floor, where it was attached to the spring.
You'd push down on the treadle, the chain would spin the gears, and the spindle would turn. The return spring would pull the chain and treadle back up, readying it for another foot push.
What could then be done is that you could mount a big, cast iron flywheel on the outboard end of the spindle, and that would provide mass to keep the spindle turning smoothly (once you developed enough momentum for it to keep going, of course).
I was so into this idea that I even had a machinist turn a spindle, complete with a #2 Morse taper. I still have it kicking around somewhere. He said that he really had a challenge matching the Italian threading on the gear cassette I gave him. But he did a beautiful job with it, and it's a shame I never did get to build the lathe. At some point I became seduced by electric power and never looked back.
Zolton * Some people say I have a problem because I drink hydraulic brake fluid. But I can stop any time I want.
Just to clarify, I thought that the pole part didn;t matter much as long as it reset the treadle since the cutting is usually done on the down stroke (of your leg) so your leg is what's generating the torque (modified by the parameters that Adam mentioned).
Seems that a light weight pole might be best, just not too light that it would have slop in it when your foot hits the floor.
Regarding the ten speed bicycle wheel, i would be inclined to simply use the rim of the wheel with it;s spokes as a form and fill it with concrete. That would be hefty enough to make a good flywheel. Actually I'd probably use mortar instead of concrete with large agregate so that I;d have a homogeneous enough mix for the finished wheel to be farily well ballanced.
Also, with the free-wheel hub in the wheel, you wouldn't have to have a spring to reset the treadle, you could use a crank connection to the wheel so you could bring the wheel up to speed and then stand still and do some turning until you bled most of the energy off the wheel.
HB
I don't have a lot of experience with man powered lathes. And I stink as a turner. But from what little experience I have, I think you are right to be concerned.
I find the lack of torque to be an advantage in that it forces you to take light cuts and never scrape. I found it was a help in learning to use the skew. My understanding is that English turners roughed with their skews. Also interesting to note is that their lathe tools had very short handles. I think they didn't generate enough torque to require a longer handle.
My advice is to go for it. Don't let your lack of green stock dissuade you from building/using a spring pole lathe. You may just need to keep your tools a bit sharper and work a bit slower with dry, hard stock. I prefer high carbon steel tools, btw. I think they take a better edge than my HSS tools (which may be of very low quality). I don't generate a great deal of heat on the treadle I've used.
Adam
Thanks Adam, the curiosity of how well it would work makes me that more interested in building one and finding out for myself. There's an old saying: "Tell me and I'll forget, show me and I'll remember, but let me try and I will understand."
btw I enjoy your articles in PW
thanks Mike
Hey keep us posted. I'm right behind you on this project. I've found the bed of my JET lathe is too short for the sort of work I need to do, so I too am looking to build a lathe.
I watched Peter Follansbee turn with a spring pole on the bed of Wmsburg's great wheel lathe last Winter. He made it look easy and very efficient. Its nowhere near as crude as one might be led to think. He did nice work with it. Ernie Conover used the wheel if I recall correctly. Ditto, he did beautiful work. I wonder if FWW has any pictures or videos they could post.
Underhill had a portable spring pole he set up in the museum or in the parking lot. He was turning aromatic cedar which turned nicely and smelled great. It made the experience really fun.
Good luck and keep us posted please!
Adam
Underhill did a show last year making a spring pole lathe. It was basically made out of 2 x stock. Probably the very lathe you saw. Don Weber the Welch Chair Bodger has a class down in Paint Lick KY making a spring pole lathe as well. I met him at The Appalachian Festival in Cincy earlier this year and I'd like to take some his blacksmithing and tool making classes sometime. Making the lathe should be a fun project. Obtaining the hardware is probably the hardest part.
Edited 10/4/2007 2:39 pm ET by mvflaim
M,
There are various designs of pole lathe and the driving "spring(s)" can vary in the amount of torque they will impart. The limitation is really the leg strength of the turner.
I know a chair bodger who has the limb of a live tree poking in through the back of his shed which is used as the spring for his polelathe. As the years pass, it is harder and harder for him to pull it down with the treadle! It turns anyfink (well, nearly).
And of course, you don't need a lot of torque, even for dry wood, as you can just take less material per whizz. You might struggle to turn a large bowl or to rough out a big round leg from a large square blank, of course. What type of turning were you planning to do with yours?
Lataxe, who prefers lecky lathes hisself (but admires the woodmen and their strong thighs).
Hi Lataxe,
I'm one of these hobby woodworkers who builds whatever I want for whatever reason and feel a spring pole lathe would be fun to build. I do have a burning desire to get a booth at craft fairs and art shows and set up a spring pole lathe as a demonstration piece to bring people into my booth and buy my wares (whatever they would be). I'd give a little woodworking lesson and sell my stuff at the same time. As far as using it, I would basically turn chair and stool legs with it. If I wanted to turn a bowl, I would probably just use my electric powered lathe and not my alcohol powered one. : )
The torque generated is the force of the push MINUS the force of the spring times the radius of the stock where the string is wound. The force of the spring increases with the travel, so guys do different and creative things to lessen the slope of the spring constant or make it non-linear. But you can increase the torque just by keeping the string on a fatter section of your stock. Also, the torque is greatest as the piece begins to move your way when the spring force is the least. I think guys get into a rhythm cutting right then.You might find this interesting: contrary to what most people would assume, the leg that gets tired is the one you are standing on, not the pushing leg. At least for me anyway, but I've heard others say the same thing.Adam
PS One of the coolest lathes I ever saw was one built using a 10 speed bicycle's rear wheel because you didn't have to pump rhythmically. Don Weber has one in some other magazine.
Hello mvflaim,
Found this web site with the remark below
Finally, keep in mind that turning with a spring pole lathe is much easier with wet wood. This style of lathe was typically put together in the forest by spindle turners so they could cut down, chop, round and turn chair parts right on site. The first time you try turning wet wood instead of dry, you'll understand why they did it this way. You certainly can turn dry wood on a spring pole lathe, but don't expect it to be easy.
Web site http://people.iarc.uaf.edu/~cswingle/woodworking/spring_pole_lathe.php
Have fun Bernhard
Sorry for the late post.
spring pole.. I assume this is the part you are asking about.
I have no idea what was used to be authentic but I have made a few Archery bows out of laminated Hickory and Ash. Alternating wood strips of approximately 1/8" thickness or less. I make so the Hickory is on the front and back. Harder to 'ding' up.
Most were about 50 Lb pull so it may make your leg tired (depending on the spring pole length..
Just my thought. I use 'off the shelf sticks' from my hardwood supplier. I'm NOT a purest...
Hi WillGeorge,
Yeah everyone I've seen used a dried out hickory branch as the spring. However, I would imagine that a piece of hickory or oak stock would work just as well as long as the grain was running lengthwise through the board so that the piece wouldn't split.
mike
MV,
I've been perusing the green woodworking books looking for any mention of turning dried wood with a polelathe. Nothing found so far I'm afraid.
The best book I know of (not necessarily the best there is) concerning pole lathe stuff is Mike Abbott's "Living Wood". This book has some detailed designs for spring pole lathes but also one or two for the bungee polelathe that was mentioned. Mike gives a bit of history concerning the various innovations to a basic springpole lathe he has made over his 30 years in green woodworking. (All small changes but adding up to a significant improvement it seems).
Perhaps Adam or another period furniture maker knows of what makers did before electric lathes became widespread. I imagine (don't know) that makers using air dried wood once used pole lathes or similar (ie man-powered) before those driven from powered belts arrived, then electric ones.....?
Lataxe
My guess is that it could be done but it's probably not very effective so that's why people used treadle lathes. But that's just a guess. Maybe Roy Underhill knows? who's got his number? : )
Mike
Edited 10/5/2007 3:43 pm ET by mvflaim
Hey Mike,
Roy's email addr. He will most likely respond. I've emailed him several times in the past, always got a responce.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 10/8/2007 3:11 pm ET by KiddervilleAcres
Hi Bob,
I've talked to Roy in the past via email as well. I think he liked me more as a kid. Now that I'm grown, I think he just think's I'm a goon.. hahaha .. just kidding
Lataxe ,
So how was it done if most all the materials were green , did they let them dry before building with them ?
In reading John Alexanders , making a chair from green wood book a few decades back it seems I remember green posts and dry rungs , was that it ?
As the post dried and shrunk , the rungs got tighter .
Turn a bunch of rungs let them dry , then tenon the ends to size to fit the green posts perhaps ?
dusty
Dusty,
Those who make post and rung chairs from green wood make the parts whilst the wood is green. The round tenons on the rungs are turned when the wood is green but these shrink to an oval when the rungs are dried. In fact, they are usually "over" dried (to about 4 or 5 % moisture content) in some form of oven or by sticking the tenons into matching holes in a light bulb box.
The posts are meanwhile bent with steam. This reduces the moisture content, strangely enough, to about 20%. Then the round tenons are drilled in the posts with an augur, in the correct places for the various rungs to seat.
The dry oval tenons are forced into the wet round mortises with a clamp. The grain is oriented so that the long axisof the oval isi n line with the post. The post shrinks as it dries to match the shape of this oval. The tenon fattens a little bit as it takes up moisture from the post. Result: a very tight fitting oval tenon in a matching oval mortise, no glue needed.
Orienting the ovals in post-mortise and rung-tenon to match like this obviates the need to shave the sides of the tenon. The post will not split, as it would if the ovals are not aligned.
The tenon/mortise diameters are fairly critical. They must be accurate to 0.1mm and to a specific size. I know the sizes for oak and ash, for chairs that will live in Britain where the usual moisture content of wood within most houses is 10 - 12%. The sizes might need to be changed for different climates or timbers, I guess.
***
The OP was wondering about turnng dry wood with a pole lathe, however. I was just wondering if cabinet makers of old used such lathes to make various spindles out of dry wood, used for various frou frou designs. For example, how did the Eizabethans (Tudors) make those big fat round legs on their tabes? Did they carve the whole thing or turn the blanks first?
Someone out there will know.
Lataxe
robert1,
where did you get the hardware? is it easily found or did you have to make it?
mike
All,
One thing that has been sort of talked around in the discussion of torque and stiffness of the springpole is the problem of slippage of the cord on the stock being turned. That is, all the torque in the world will not be of use if it isn't transmitted to the turning blank.
A stiffer pole will increase the tension of the cord against the stock, and increase friction between cord and stock. Some lathes have a means of adjusting the length, hence the stiffness, of the pole.
Additional wraps of the cord around the stock increase the surface area, and so, the friction.
Rosin applied to the cord makes it grab better too.
Touching the lathe tool to the cord on the downstroke is a bad thing.
Ray
Ray,
Does it matter what material the cord is? Should I stick to a leather cord or can I use a rope of some sort?
mv,
My buddy George's springpole lathe has a leather cord (more of a narrow strap). To get the most impetus, I think that will prove to be better than a round cord or rope, which will have less surface area in contact with the stock.
Edit, no reason you can't use a rope to get from the pole to just above the lathe bed, then tie/splice a length of leather strap to wrap around the stock.
Ray
Edited 10/9/2007 9:54 am ET by joinerswork
That's a good idea. Thanks Ray
I saved your links!
Springs for Medieval and Renaissance Lathes! I love it!
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