Adventures with a Spring Pole Lathe
pastorchairmaker | Posted in Turning and Carving on
Hello to the FWW Crowd,
I need some advice on enhancing the performance of my spring pole lathe. I use it for demonstrations at an 18th century site. Several years ago I built one based on Hulot’s portable design featured in Roy Underhill’s The Woodwright’s Eclectic Workshop. I made my pole out of about 1 1/2″ diameter osage orange stock, but I don’t seem to get a fast enough return. Perhaps I either need to replace the pole or I should add some additional clamping to limit its flex. So far I’ve tried using rope to dampen the flexing of the pole, but it didn’t help enough.
Jim
Replies
I think you would get better advice if you could post some photos. Your choice of wood sounds good, but there are other factors which would affect the results.
Also try to give more dimensions. One dimension of a three dimension object leaves too much for me to incorrectly imagine.
I would imagine that your 1 1/2" pole has a length, with one end attached, and somewhere along that length would be a fulcrum. How long is the pole, and how far is the fulcrum from the base. Is there a tapper to the pole? How heavy is your foot peddle?
How big and heavy is your object being turned, and what about friction between its centers?
Thanks. I'll do that. Here are some details. The pole is about 5 feet long. It is attached at the end opposite to the top mounted lever. It has a uniform diameter. The pedal consists of a 2 foot long piece of white pine with dimensions of 1" x 6".
Jim
Thanks Jim, that helps, but ha, the details which I would like to see, were just out of those photos. Now I have never used one of these things, but I have built a lot of my own tools and equipment that work pretty good, so here are just a few things that I think may be worth consideration. If I understand what I can see in the shots, the spring pole is there across the bottom legs. Sure seems like it would be a good idea to have the fulcrum adjustable, so it could be slid right or left, to increase or decrease the spring-back. I can't tell much about the rocker out of the shots above. If this is hard, and heavy, this may slow it down, as well as tight bearing point. Also the distance from pivot point to the power side / to the rope that goes around the work, relationship comes into play. I don't know if the foot peddle board has a pivot point, but it seems that it could have a short arm on the heel end, where you could slide your foot back, and give it a tap to lift the far end, which should allow the string to slip around the work spindle rather than spin it backwards. I am not sure I can see the benefit of that top arm. It seems to me that the line from the end of the pole could just go up and over a block / pulley, and back down around the work more efficiently than what I can see here. I hope you can find something in my ramblings useful. Good luck, K
Hi Keith,
I appreciate the input. I'll take some better photos in the near future. I followed the plan in Roy's book pretty closely. Getting the vertical arm and lever aligned over the lathe bed was tough. So that is part of the reason for the lever, to get the cord right over the bed and near the pedal location. You might not be able to see it, but the arm has a twist. The lathe design dates back to 1775.
I did change the pedal though and gave it a pivot point. I attached it with hinges to a 2 x 4 that runs right in front of the front legs. It made it more manageable.
It is fun to use, but getting a faster return is my goal. I am thinking about using a couple U bolts to adjust the fulcrum on the pole.
Jim
Check out the spring pole lathe in Roy Underhills lates book, Working Wood with Wedge and edge. It uses two spring poles with adjustable tension. I have been masking rolling pins on one since December. It has very snappy return with the tension set up properly. I use a pine 1 x 4 24" lone hinged at the heel atached to a peice of plywood.
but I don't seem to get a fast enough return.
I am no expert.. But try some Ash poles.
OR Hickory as in Pecan...
Edited 3/9/2009 7:09 am by WillGeorge
Same guy, different hat.I built a treadle lathe, with concrete flywheel and all - but my 75 yo legs could not keep it going at the desirable speed, so now it has an electric motor.Following this thread, I tried googling 'spring pole lathes' in images.
There are some excellent pictures of the Underhill lathes in the Williamsburg establishment. There are many fine examples of more rustic set-ups.I can't help feeling that taper in a wooden spring is fundamental in creating a range of spring rates appropriate for variable loadings. The old english long bow was so effective as a weapon because the archer was able to determine a 'power = range' equation. And he used Yew.Lapun.
Thanks guys. My spring pole lathe will be getting a work out fairly soon as temps warm up. Your ideas are on the mark. Since my post I learned that on Roy Underhill's Hulot lathe he left more wood at the fastening end (square end) which amounted to a gentle taper. I could also revamp my lathe to accomodate a spring based on his new style of spring pole lathe.
Currently, I mounted a 20' pole on the ceiling and it has more spring that I can use. The good part is that I can use my lathe for now until I get it configured with a new spring for portable use.
Take care,
Jim
Jim,thanks for the feedback. I look forward to further 'adventures & results' during the summer.Lapun.
ALL,
My father in law will be comming to visit in April. I told him I'd show him how to make bowls. His name is Wozniak- so I guess I 'll have a Spring Pole Lathe too!
Frank
Is his christian name Steve? Maybe he needs bowls for all his apples!
With two spring pole lathes, you'll need to get your 'toin' & 'froin' in sync.Lapun.
Actually I think he is a distant (poor) relation of some sort. He is however, a great guy.
Frank
Technically, what you have is a spring lathe. A pole lathe has a long (14' to 16') pole anchored to the ground at one end and supported at a point, determined while setting up the pole, by an a-frame which is all completely seperate from the lathe frame. You will have to adjust your spring and modify its mounting to get what you can out of it. If you find it unsatisfactory you might just have to replace it altogether. I use a white oak sapling, but my lathe is outside all the time. I see a lot of modifications for treadle turning but the spring pole seems to have the best return for the effort.
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