Another spring pole lathe guy

[Jim Paulson]

Hi everyone,

I built a spring pole lathe several years ago and it followed Hulot's 1775 design as featured in Roy Underhill's The Woodwright's Eclectic Workshop. I have had fun with this doing demonstrations, but the return doesn't seem to be fast enough. I made the pole out of 1 1/2 " diameter osage orange and it is about 5 feet long. According to the design, I fixed it at the end and that way the whole pole can flex during a stroke of the pedal.

Bob Glenn evidently made the more recent style of spring pole lathe that Roy is using. It looks like I need to do something with the pole on mine and I'd be interested in your thoughts. I am thinking that I might need a couple U bolts to change the fulcrum and possibly get a faster return.

Jim

[Paul Atkins]

How about a picture? Changing the fulcrum might get your return faster, but the down stroke might be harder. Try moving the cord down the pole 6" at a time to see what a shorter pole (stiffer) would do. The only pole lathe I've tried was in Del Stubbs backyard with a live sapling. Not sure what tree it was, but possibly black locust.

[Jim Paulson]

Thanks Paul. I have some photos, but not a good one of just the whole lathe. I'll post one soon on this thread. Did Del Stubbs try turning a bowl on his foot powered lathe?

Jim

[Robert Rozaieski]

I think what you want is a longer top arm. The pole at the bottom provides the power but the lever at the top provides the speed. The design of these lathes (power pole or poles on the bottom and lever on the top) are designed so that minimal movement of the spring pole will result in maximum travel at the end of the upper lever. You are not going to get more speed unless you change the point of the upper fulcrum or extend the length of the upper arm from the the pivot point to where the cord attaches. By making this length longer you increase the radius of the arc and therefore get more travel length at the end of the lever (i.e. a wider arc). This will provide more speed per stroke but less power. Speed and power are inversely proportional in these designs. FWIW I have not built mine yet but Roy's newest spring pole design is the one I'm planning to build after the holidays. The design principle is the same as the Hulot design though.

[Jim Paulson]

Hi Robert,

This is fun getting input from you and the others. The lathe works. Given the energy one puts into it, I'd just like to optimize it. The attached photos aren't pretty, but hopefully helpful. You can see my attempts to alter the fulcrum somewhat by using rope.

The vertical arm that supports the top lever has a twist which was a bear to make, but it achieves the purpose of getting the cord nearly centered over the lathe bed and the pedal. Equipping this with a longer top lever would mean changing the inclination and the twist of the vertical arm. The top lever on the Hulot lathe is 36" versus 52" on Roy's new spring pole lathe.

Who knows maybe I'll build my fourth foot-powered machine. I have plenty of power tools, but this is a kick for me.

Thanks,
Jim

[Bob Glenn]

The spring pole lathe I made and use a double spring pole directly under the turning centers and lever directly over the centers. The spring poles are both secured to the lathe stand on the left hand side, and only the bottom pole is secured on the right hand side, leaving the top to flex. I tie the two poles together in the middle with a rope so both poles will flex. I can adjust the tension by sliding the rope either left or right.

My lever goes all the way across the top of the lathe bed, thus offering a longer pull, thus more rotation. Consequently, this calls for more tension and stronger poles. I use two Ash spring poles about five feet long and lever is about six feet long. As I recall, I had to lighten my treadle to get the spring poles to raise the treadle back up. Another thing I did was to raise the treadle angle so it was at about a sixty degree when it was ready to cycle.

If I can find a picture of my set up, I'll try to post it here. I only use the lathe to do eighteen century reenactments, and it knocks down for transport, so I don't have it set up in my shop, or I would take a picture of it now.

I is really difficult to do any detail work on this lathe, since you have to put the lathe tool back slightly on the rewind stroke, then put it back in the same place as you step on the treadle. I am considering converting it to an actual treadle lathe with a fly wheel and for continuous rotation. However, people just love watching the operation of the spring poles and lever action.

I think you'll have work with mechanics a little to get your lathe work.

Bob Glenn

[Jim Paulson]

Hi Bob,

I agree that I'll have to tweak this thing some more. I've been using it to make Windsor chair legs in demonstrations, but I can't blame the lathe or my tools for everything. I confess my physical conditioning needs some enhancement too. Thanks for your comment. I am glad your still using your lathe.

Take care,
Jim

[Scott Lux]

You might try a new spring pole.

My understanding is that everytime a longbow (another spring pole device) is used, it loses some of it's strength. I found this in a book on bowmaking a couple years ago. BTW Osage Orange is a favored wood for that too.

A lathe spring pole is going to go through a lot more flex cycles than a bow would, so it makes sense to me it would soften quicker.

Just a thought.

Lux

[Allen Neighbors]

I don't know anything about that sort of lathe, but I love to see them in action! You gotta have a lotta heart to do this much work.
Looks good! I'm ready to see the others, now.

[Bob Glenn]

Jim, I make Windsor chair legs at demos also. I really don't feel it is too taxing when I'm pumping away. Maybe like a fast walking pace. However, I have to switch legs frequently. I just can't imagine the old bodgers making a claimed 100 legs a day back in forests around High Wycombe, England. They must have really been something!

Bob

[Jim Paulson]

Heh Guys,

This is fun sharing about these lathes. I'm focused on the spring pole lathe because it is portable and I resisted the temptation to carve it. I can slide it in the back of my truck and not worry too much about the finish on it. It is meant to be used.

Thanks Allen for your comment. When I built my treadle lathe I followed Roy's design pretty close, but I did a bunch of chip carving on it. Upon seeing it for the first time my son said "Dad you turned a machine into a work of art". Seriously, it looks too nice to take on the road for demonstrations. It does serve as a nice conversation piece when people come in my shop. Everyone wants to try it.

Take care,
Jim

[robin wood]

Personally I would try setting it up with a proper pole to get a feel for how that works. It is very easy, just cut a pole maybe 15 feet long tapering from something like 2-3" at the base to 1" at the top. Set that over your lathe and you will have lots more spring and longer travel. Once you know what it should feel like then you can experiment with the small portable system but there really is nothing to beat a big pole.

[Jim Paulson]

Hi Robin,
Thanks for making that suggestion. It makes sense to try using a large pole so I would have a feel for how the lathe should work. By the way, have you posted a picture of your lathe? It would be neat to see what kind of setup you use. It must have taken quite a bit of doing to make those bowls. That was beautiful work.

Jim