Treedle Lathe




Introduction: Treedle Lathe

Yep, the title is a pun, sorry.

If you've ever watched much of Roy Underhill's show The Woodwright's Shop on PBS, you've seen him use a self built treadle lathe. If you haven't watched much of Roy Underhill's show, why not!? Seriously, look up if/when it shows in your area and watch it!

I'm working on a wooden sailboat mast. It is 14 feet long and constructed with the birdsmouth techinique. I wanted to round it, but a lathe capable of handling a 14 foot long workpiece isn't exactly common... or cheap. So, what to do? I started out with an octagon; the shape the birdsmouth build produced. I used a hand plane to knock off the corners to make it 16 sided. Then again to make it 32 sided. That is pretty close to round. How does one make it rounder? Sanding.

One common way of sanding masts is to turn a belt sander belt inside out and use a drill equiped with a disk to turn it. I don't have a belt sander and as such no belt sander belts. I didn't really want to buy one, nor did I want to stand around running a drill for a long time. Especially since my drill isn't really that good of a drill. I came up with my own way.

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Step 1: Tools and Materials

Scraps of wood
Something to attach string to and throw

Step 2: The Spring

You want a flexible overhead tree brance to use as a spring. Make absolutely sure it is a live branch. A dead, dry branch would likely snap off and fall on you. Look at it closely, even if the main branch is live, other parts may be ready to fall off. A maple in my backyard had a good looking branch. Longer is better, you can move the rope along it to achieve the desired springy-ness. Don't worry about harming the tree, a windy day puts as much or more stress on the branch than what you'll be doing.

You need a rope over that branch. I used an old tennis ball with a hole poked through it for my throwing weight. Tie the string to the weight and lay out a bunch of string on the ground (roughly 2x the height of the branch above the ground) and make sure it isn't tangled or snagged on anything. Throw the weight over the branch and work the string up and down to get the weight within reach. It took me many, many tries. I think I hit the branch 7 or 8 times. I managed it over a few times, but couldn't get it to come down so had to pull it back and start over. Other times, I simply threw it under the branch.

Once the weight is over and within reach, cut off the weight, tie a loop in the string, and feed many feet of rope through the loop. Don't tie it, or the knot might get caught. Use the string to pull the rope up and over the branch. I tied the rope into a big loop that hung a foot or so above my head. That way, I can untie it and easily pull it down when I'm done.

Step 3: Work Support

Set the sawhorses under the tree so the workpiece will fall directly under the rope loop. Use the wood scraps and screws to build a cradle for each end of the workpiece. Capture it so that it can't move up and down, back and forth, or side to side, just spin. My mast has a 1.25 inch octagonal plug protruding from each end, those rest in the cradles I built. Set the workpiece in and make sure it will spin relatively easily. Depending on the weight and stability of the sawhorses, the weight of the workpiece and the springy-ness of the branch, it might be a good idea to stake the sawhorses to the ground or otherwise prevent them from moving.

Step 4: The Drive Rope and Treadle

I used another piece of rope (the drive rope) to attach the treadle to the hanging rope loop. This way, I could adjust the length more easily. One end was tied to my treadle, a piece of 2x2 lumber which was painted black for some reason. Wrap the drive rope around the workpiece a time or two and then tie the other end to the rope loop hanging in the tree. If the drive rope slips instead of turning the workpiece, add more wraps. Use as few wraps as you can get away with, otherwise they might ride over each other and lock up. I started with two wraps, but after I'd used it a bit, the cradles wore smoother and one wrap was sufficient.

Later I discovered that the direction of wrapping can be important. It was easier to have the end of the drive rope connected to the treadle closest to where I was standing. Positioned with it on the far side, it had a tendency to over-ride. The drive rope can be moved up and down the workpiece to some extent as necessary to work on different areas. The sawhorses can also be moved in relation to the branch to re-position the drive rope.

Step 5: Use

It is now all set up. Simply stand next to it, put one foot on the treadle and start pumping. The position of your foot along the lenght of the treadle controls how hard it is to push vs. how far you have to push. Place it close to the drive rope and it is easy to push, but you have to push it a long way. Place it close to the end of the treadle on the ground and you don't have to push it far at all... if you can push that hard. Pushing down rotates the mast one way, letting up allows the tree branch spring to rotate it the other way. It is a good workout, see if you can "Tom Sawyer" someone into pumping it for you for a while. My four year old son was more than happy to try, but doesn't weigh enough.

I was sanding, so I held strips of sandpaper against the mast. If one is feeling daring and wants to do a little more shaping, another sawhorse might make a useable tool rest for a lathe chisel. Since it is relatively low speed and low power, the risk of injury is somewhat reduced. Still, don't be stupid. The rope can pinch, a chisel could catch and be thrown, you could lose your balance and fall, the tree branch could break and fall on you, etc.

Sorry, I didn't take a lot of pictures. A video of it in use would have been good too. Maybe next time.

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    11 Discussions

    Very nice. Just one thing. That's a pole lathe, not a treadle lathe.

    A treadle mechanism makes use of a large flywheel to power the spindle. When the foot pedal is moving through the "up-stroke" so that it can be pushed again, the flywheel continues to power the spindle "forward." This actually allows the lathe spindle to achieve much higher RPMs than the pole lathe can, since that on each stroke (down and up) of the pole lathe, the spindle has to come to a stop and then spin in the opposite direction. Each stroke then has to overcome inertia rather than building on the momentum of the previous down-stoke. This is why the treadle lathe was an improvement over the pole lathe and why it eventually replace the pole lathe. Eventually, the treadle mechanism was replaced by a pulley system powered by water wheels, then steam engines, and eventually electric motors.

    However, the advantage of the pole lathe is that it is easier to construct than the treadle lathe, especially since it requires virtually no engineering. The advantage of both the pole and treadle lathe over modern lathes is that you don't need to have an electrical source near by.


    7 years ago on Step 5

    This isn't a treadle lathe, but a spring pole lathe.


    7 years ago on Step 5

    This is a great idea! Thanks for sharing and good luck with the boat!


    7 years ago on Introduction

    Years ago I built a spring pole lathe between 2 trees following pictures from Foxfire 2. The summer after graduating high school, I went with my family to Branson and a trip to Silver Dollar City. It was amazing to discover thatmy 12 year old self had built a lathe almost identical to the one that a craftsman was using there. After my mom said something about mine the craftsman invited me behind the rope with him to use his lathe. Wow the memories this can bring up, now it is time to build another only this time with pictures.


    7 years ago on Step 5

    How did you get my sawhorses out of my yard?

    Looks like a neat system - thanks for sharing!

    I wonder if it was feasible to adopt the system on a smaller scale for my workshop. I have a lathe which can do pieces up to about 2cm in diameter, and maybe 20cm long. I think I'll have to give it some thought. It probably cannot beat anything motorized when it comes to smaller pieces or more ambitious work than rounding, but who knows... I'm definitly putting that on my list.


    Reply 7 years ago on Introduction

    You bet you could build one to handle something smaller. Do a Google image search of "treadle lathe" and you'll see all kinds from home built to ones which were once commercially available. Put enough design work and construction effort into it and you could produce turnings which rival those you could produce on a motorized lathe. Here's kind of a video diary of a guy building one. I believe Mr. Underhill has a book out there which has plans for one also.

    Phil B
    Phil B

    7 years ago on Introduction

    We saw a reconstructed facsimile of one of these lathes in a Roman museum in Augsburg, Germany. We also attended a medieval festival in Dornum (Ostfriesland) Germany where a young couple was selling items made from wood. They had one of these lathes set up for making some of the items they were selling. These lathes have a long history, even if the beds on the two we saw were shorter than what yours shows.