I’m unaware of anyone using pulleys for mechanical advantage on a pole lathe in the Neanderthal days, but I saw a youtube video of a guy with some pulleys doing SOMETHING other than just redirecting the rope. The problem was he never showed the whole setup. After watching every one of his pole lathe videos (no talking, more just selfie videos turning) I found him confirming in a comment that the pulleys were for mechanical advantage. If you’ve ever used a pole lathe you know that possibly the two most important factors are a) turning speed and b) number of revolutions per treadle stroke. So I was off to the home center!

My pole lathe is powered by a bungee since I don't have the ceiling height necessary for a real pole (which would also be a pain in the butt). Originally my power cord was tied to the treadle, wrapped the stock, redirected by the pulley at the soffit and then connected to the bungee (a single bungee; not a double) strung across a very heavy and essentially immovable utility bench. This would be your normal pole lathe scenario (just with redirecting the power cord because of the low ceiling combine with a tall operator). With this setup, on a typical 1.5” diameter piece of stock I could easily get 7 or more revolutions per stroke.

Now, instead of being tied to the treadle, the power cord is tied to the lathe itself and hits a pulley on the treadle before wrapping the stock. This gives me (theoretically) double the cordage to turn the work for the same treadle travel. The problem is that would require the bungee (pole) to travel twice as far, which it obviously can’t do. So instead of tying the cord to the bungee it goes through another pulley that is attached to the bungee and comes back and is tied to where there redirect pulley is. This makes sense if you look at the pictures. So my theoretical 2:1 at the treadle is inverted 1:2 at the bungee and I’m back where I started, just with double the cordage travel and double the speed. There’s no free lunch of course, and the bungee suddenly had half the strength required to bring the treadle back up. Simple solution – something you can’t really do with a pole very easily – I just cut another length and doubled the bungee power. Now I get double the turning speed and double the number of revolutions and everything feels and functions like normal. In reality it’s not really double because things don’t work that way in the real world. But it’s close. In fact, I sometimes have found I need to treadle more slowly because the speed of the spindle can get ridiculous.

I’ll explain a few confusing things in the photo. There are a series of nails in the soffit – that’s because when I’m turning something longer, I may need to move the redirect pulley. If I had a pole up 10 feet in the air it wouldn’t be such a big deal. But that redirect pulley is only a few feet above the lathe and the angle can get kind of tight. Some people simply flip their stock around, but that sounds like a pain. Originally I had three, but then I worked on a really complicated piece and putting in a could more nails for some more options really helped. The other thing is that on a normal treadle, if you need to take up slack (as your stock gets smaller in diameter) you simply give the cord another wrap around the treadle. That’s not possible for me now, so I take it up at the opposite end where the power cord ties onto those very same nails. Now I can take up slack just by giving a wrap or two around a couple nails.

ma1.jpg
ma2.jpg