Saturday morning experiment

[Nicholas Lawrence]

I have been curious about the spring pole lathes for a while, and decided to knock together an experiment with what I have laying around. This is nothing remotely like a thought out design or a finished concept, so those of you who see obvious design flaws are correct!

I took a piece of leftover 2x8, and ripped it down to make the uprights. It was about 3/8 too thick to fit in the holes on my bench, so rather than rip it both ways, I planed it down.

To do that I mark the finished depth with a gauge, and then plane to the line at a 45 with a block plane. The 45 helps avoid overshooting the line, and also helps avoid blow out on the sides.

IMG_0133.JPG

A little work with a scrub plane, and I will move to my jointer to get to the final thickness.

IMG_0134.JPG

Rip, and then crosscut to finish sizing to fit in the holes.

IMG_0135.JPG

Add some lag bolts I have laying around, and I have something to hold the piece I want to turn. The return power is a bungee cord doubled up in the ceiling. If my wife asks, yes, that is a lifetime supply of 550 cord!

IMG_0136.JPG

Here is the "finished" product, or at least as far as I think I will take this one.

IMG_0137.JPG

I underestimated the amount of force involved. Just sticking the tail pieces in the holes in the bench worked surprisingly well though, as did using a countersink bit to make a divot in the end of the piece I was turning to allow the lag bolts to catch. The lag bolts obviously are not a real solution to hold the stock, because there is nothing to keep them from loosening, and they take quite a lot of force on the downstrokes. 2.0 will have something different, maybe bolts, with the ends rounded, and a nut to keep everything tight.

The real problem is the power. The bungee cord does not allow enough travel, and I am not getting enough rotation before it starts to rotate back. Either that or I need to figure out how to do more with the rotation I have.

It is a neat approach to turning though, and even this little experiment was enough to show me that it requires a much different approach than with a powered lather that is spinning constantly at a much higher RPM.

For folks who have used full size spring pole lathes, do you use the same turning tools used on a power lather, or something different?

[Warren Mickley]

I have used pole lathe since 1981. I use a 13 foot hickory pole which tapers from 2/14 to 1 3/4. I had previously used a treadle lathe and an electric lathe, but by the second day on the pole lathe I was doing the finest turning I had ever done.

As to tools, the efficient tools are cutting tools: roughing gouge, coving gouges, skew chisels. Scraping tools are slow and leave a poor surface. Parting tools are also slow and clumsy because they scrape at the edges of the cut. I use the same tools on the pole lathe as I use on an electric lathe, or treadle lathe or great wheel lathe. However, most people who use electric lathes use techniques which would be exposed as inefficient with the pole lathe. In other words you can get away with more sloppiness with the power lathe; the pole lathe demands (and teaches) clean technique.

I don't recommend the tinker toy lathes: bungee, bow, or the portable lathes with the built in poles. It is hard enough to learn to turn without working on something flimsy. Firmness in both lathe and pole is very helpful.

[Bob Glenn]

I use basically the same turning tools on both my powered lathe and spring pole lathe, but there IS a difference. Since the rotation on the pole lathe will be slower, the tools must be a lot sharper to work well. I usually take my powered turning tools right off the grinder (with the exception of the skew) and put them to use. I have found spending some time honing my pole lathe tools pays off. Also, many pole lathe turners use tools ground with at 20 to 25 degree bevel on the cutting edge.

[Nicholas Lawrence]

I don't recommend the tinker toy lathes: bungee, bow, or the portable lathes with the built in poles. It is hard enough to learn to turn without working on something flimsy. Firmness in both lathe and pole is very helpful.

Thanks for the advice and insight. I think you may be right, but it is fun to experiment. The bench is stable, and the uprights are very solid in the bench holes. I think with a little modification I can get the piece held firmly enough. The pole is a problem though in the space I have. I agree with you that the bungee cords are not going to work regardless of the amount of modification. I don't have 13 feet for a pole though, so this may be one of those things that has to wait until I have more space.

[Frederick Skelly]

Cool experiment Nick. Keep us posted if you take it to the next iteration!
Fred

[Frederick Skelly]

I don't recommend the tinker toy lathes: bungee, bow, or the portable lathes with the built in poles. It is hard enough to learn to turn without working on something flimsy. Firmness in both lathe and pole is very helpful.

Warren, is there any chance we could get you to post a couple pictures of your lathe? I googled pole lathes but I think the images that pop up are the ones you recommend against. I'd sure appreciate a chance to see how you have installed that long pole and where it is placed relative to the lathe itself, Sir.

Thank you!
Fred

[Judson Green]

I don't recommend the tinker toy lathes: bungee, bow, or the portable lathes with the built in poles. It is hard enough to learn to turn without working on something flimsy. Firmness in both lathe and pole is very helpful.

Pardon my ignorance, but whats wrong with a bungee or other type so long as the lathe is sturdy? Isn't the function of the spring pole merely to sort of rewind the turning?

[Warren Mickley]

I don't have too much in pictures. Here is one outdoor picture where the pole is tied to a tree. In the shop the pole is suspended from the ceiling joists.
DSCN7451m.JPG
If you search "roubo lathe" you can probably find an old picture of me.
Here is a plate showing the set up of an 18th century turning shop showing the pole configuration. It is nice if you can move the pole back and forth a bit to get the tip right over the place where the string is wrapped around the work.
hulot lathe stock prep.jpeg

[Warren Mickley]

Pardon my ignorance, but whats wrong with a bungee or other type so long as the lathe is sturdy? Isn't the function of the spring pole merely to sort of rewind the turning?

The spring puts tension on the cord throughout the stroke. If there isn't enough tension, the work kind of stalls when the cut starts, kind of like a weak motor would do. With a bungee cord the tension varies dramatically from the beginning of the stroke to the end. What you really want is the steady firm tension for the whole stroke that a pole provides. A short pole also changes from loose to firm in too short a range to do fine work.

If the spring were merely to return the stock for another stroke it would not be an issue as you point out.

[Jim Koepke]

The spring puts tension on the cord throughout the stroke.

Could a pulley and a weight at the end of the rope be an effective way to do this?

At least if one kept their head from under the weight...

jtk

[Joe A Faulkner]

Here's a short utube on an in shop set up.
https://www.youtube.com/watch?v=1y7STSYzje8

[Warren Mickley]

Could a pulley and a weight at the end of the rope be an effective way to do this?

At least if one kept their head from under the weight...

jtk

The trouble is that the treadle is moving 60 to 90 times a minute; a weight could not bounce around that fast. Too long to get it moving, too long for it to stop and start coming down, might bounce at the bottom.

Nicholas, keep up with the experiments. It is well worth the effort.

[Frederick Skelly]

I don't have too much in pictures. Here is one outdoor picture where the pole is tied to a tree. In the shop the pole is suspended from the ceiling joists.
DSCN7451m.JPG
If you search "roubo lathe" you can probably find an old picture of me.
Here is a plate showing the set up of an 18th century turning shop showing the pole configuration. It is nice if you can move the pole back and forth a bit to get the tip right over the place where the string is wrapped around the work.
hulot lathe stock prep.jpeg

Many thanks Warren. Those were just what I needed to see to understand it!

I've never had a chance to do any turning. But every time I hear someone talking about spring pole lathes, I get more and more interested in building one some day. It's just simple and, well, just plain elegant.

Fred

[Jim Koepke]

The trouble is that the treadle is moving 60 to 90 times a minute; a weight could not bounce around that fast. Too long to get it moving, too long for it to stop and start coming down, might bounce at the bottom.

Nicholas, keep up with the experiments. It is well worth the effort.

Thanks for the explanation Warren.

jtk