Pole or Bungee

discussion of the niceties of turning on a bow, bungee or pole lathe.

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Re: Pole or Bungee

Postby simon » Mon Aug 31, 2009 5:59 pm

Sorry to keep you waiting, been off sailing with my brother.
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A box around the wheel. Holes in the sides for the axel, a snug fit.
The top is long enough to slide into the gap between two planks fixed to ceiling.
the planks have spacers between them at each end.
It is arranged so that only string runs over the wheel. It is about 10' from the wheel to where the string/bungee is fixed, about 3' of that is bungee. It is quite easy to adjust the length of bungee in use to get the feel you want.
Make it, mend it, wear it out,
Make it do or do without.
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Re: Pole or Bungee

Postby Bob_Fleet » Sun Jul 29, 2012 8:03 pm

I've just had a great weekend at the Border Union Show.
I treated my apprentice John to some bungee as part of his wages.
Here's the result.
http://www.onegoodturn.co.uk

Society is like a stew. If you don't keep it stirred up, you get a lot of scum on top.--Edward Abbey

Come and see us all at http://www.wooplaw.org.uk
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Re: Pole or Bungee

Postby jrccaim » Mon Jul 30, 2012 5:36 am

My observations on this thread take three forms. One is nomenclature. If the thing uses a bungee cord, it is no pole lathe. Rather than call it a bungee lathe I prefer the term reciprocating lathe as a generic term. After all for my first such lathe I used a screen-door spring attached to the ceiling! Should I call it a "screen door lathe?" :). (Aside: it wore out. I suspect reciprocating lathes provide a real stress test for door springs.) On the other side we have continous motion lathes. They may be treadled or motored. Out of scope.

I have absolutely nothing against pole lathes. On the contrary. Thing is, poles take up a lot of room. That is why bungee is so popular. You can fit it into a very small space. If you turn a 3 cm diameter piece, the circumference is 10cm. (I rounded pi up). If you want say five revs per treadle then you need a 50 cm stretch. Bungee will do this. So will a pole. Break even. But bungee is much more compact. Half a meter is probably excessive; we don't usually get that much. However we could call this the stroke of the lathe. The distance from the tip of the treadle to the ground is your maximum stroke. That's why you want the tip of the treadle way up in the air. And why you make the treadle very long.

My second observation has to do with things breaking and causing damage. The damage may be to the piece. Too bad. But it could also damage the turner and that is much worse. With bungee ceiling hooks are to be avoided. If they tear out they might catch you in the eye. In fact metal fittings are subject to suspicion for that very fact. A hook may work for a bungee anchor. But make sure it's way oversize and that the pull direction is not along the axis of the hook.

Third observation is esththetics (aesthetics if you prefer). Clearly bungee is not traditional. If you want something absolutely authentic that does not take up too much space try a bow lathe. Not the lathe that uses a bow for power, instead use a bow as a spring. I warn you from direct experience that is no easy matter to "tiller" (that is, shape) a bow to do what you want. Roy Underhill has some directions on this. He does not give the dimensions of the bow! That gets you into bow-making and we could fill up a forum the size of Bodger's board on the subject. There are also short springy poles attached to the bottom of the lathe. The only trouble with these arrangements is that the stroke is short, say 30 cm. So it's more work. As usual it boils down to personal choice.
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Re: Pole or Bungee

Postby Davie Crockett » Mon Jul 30, 2012 10:40 am

jrccaim wrote
Third observation is esththetics (aesthetics if you prefer). Clearly bungee is not traditional. If you want something absolutely authentic that does not take up too much space try a bow lathe. Not the lathe that uses a bow for power, instead use a bow as a spring. I warn you from direct experience that is no easy matter to "tiller" (that is, shape) a bow to do what you want. Roy Underhill has some directions on this. He does not give the dimensions of the bow! That gets you into bow-making and we could fill up a forum the size of Bodger's board on the subject. There are also short springy poles attached to the bottom of the lathe. The only trouble with these arrangements is that the stroke is short, say 30 cm. So it's more work. As usual it boils down to personal choice.

My bow lathe has a working travel of 65cm at max pull, and I've had to mount it directly above the work-piece. It's starting to follow the string a bit now but the details of the bow are: Yew Branchwood (75mm (3") Dia) from a horizontal branch with a slight upward curve. Ideally this should have been 100mm (4") or more and straight but as I had rescued it from a bonfire there wasn't any choice.

The rough bow stave was 132mm (52") long.
Finished dimensions of the bow: Length 127mm (50"). width at centre 25mm (1"). Tillered down to 15mm at the ends maintaining equal heart and sap wood down it's entire length. The drawstring is 122mm (48") It has a 20-25lb pull which is more than adequate for my needs.
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Re: Pole or Bungee

Postby jrccaim » Thu Aug 02, 2012 4:28 am

Bravissimo Davie. Even with the English edge of having yew available it is no mean feat to get the right tiller on the bow. I admire your bow. No, I am downright jealous :). I think your lathe is beautiful.
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Re: Pole or Bungee

Postby ToneWood » Thu Aug 02, 2012 2:17 pm

It's "easy on the eye" too. Clean, minimalist lines - surprisingly modern looking. Would have been a good design to incorporate in the recently proposed (all-white) design show wood-turning exhibit.
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Re: Pole or Bungee

Postby simon » Thu Aug 02, 2012 4:01 pm

The rough bow stave was 132mm (52") long.
Finished dimensions of the bow: Length 127mm (50"). width at centre 25mm (1"). Tillered down to 15mm at the ends maintaining equal heart and sap wood down it's entire length. The drawstring is 122mm (48") It has a 20-25lb pull which is more than adequate for my needs.


When I made the bows for my Bodgers Muddle, http://www.bodgers.org.uk/plans-menu/59-muddle, I split some fairly straight ash, made it thinner at the ends and thicker in the middle and used it. I don't remember measuring much apart from the lenght. It is still working well after several years use even though there is a knot quite close to the fulcrum of one of the bows.
They bend, they spring back. If it aint bust........
Make it, mend it, wear it out,
Make it do or do without.
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Re: Pole or Bungee

Postby Steve Martin » Fri Aug 03, 2012 5:34 am

AWESOME!!! What tool did you use to make the middle thicker? :lol: Will it work to make walking sticks longer when you cut them tooooo short? :lol:
Sorry, I couldn't resist. As you implied, some of my best first attempts were because I didn't know I wasn't supposed to be able to do it (whatever "it" was).
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Re: Pole or Bungee

Postby ToneWood » Sat Aug 04, 2012 7:44 pm

Ah, so you're that Steve Martin! (Just kidding ;) )
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Re: Pole or Bungee

Postby Robin Fawcett » Thu Aug 30, 2012 3:37 pm

or Bobbin? See my new YouTube vid https://www.youtube.com/watch?v=jGu_wWZ2iQE - another great alternative.
http://www.facebook.com/GreenWoodwork?ref=tn_tnmn[url=http://www.treewright.co.uk/]
Green woodwork courses, treen, demonstrations & talks http://www.treewright.co.uk[/url]
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Re: Pole or Bungee

Postby Susan Green » Mon Sep 03, 2012 9:00 pm

Just watched the bobbin video. Great selection to see, Robin. Have you tried a bobbin with a bowl lathe? I'm coming up to finishing off one and wonder whether to give it a try. Very useful and accessible for anyone.
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Re: Pole or Bungee

Postby Robin Fawcett » Mon Sep 03, 2012 10:44 pm

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Yes Sue, the bowl I'm making in the header of my facebook Page was with a bobbin...
http://www.facebook.com/GreenWoodwork?ref=tn_tnmn[url=http://www.treewright.co.uk/]
Green woodwork courses, treen, demonstrations & talks http://www.treewright.co.uk[/url]
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Re: Pole or Bungee

Postby jrccaim » Tue Sep 04, 2012 5:23 am

Really great video. Many of the YouTube videos are very boring in places, this is just right. Enough detail so's you could make your own, not a scene that is not necessary. Dialogue right to the point. Not one word too much or too few. Video-makers please note! Writers say "there is never a piece of writing that cannot be improved by ruthless editing." Same thing applies to video.

There are days I wish this topic was labeled "reciprocating lathes." Too late. Reciprocating lathes rely in some form of spring to return the lathe to where you started. I love them all, there are many forms of spring. Bobbin is YAS (Yet Another Spring) and poles, bows, bungees, door springs, they are all springs. Bobbin relies on the tendency of twisted cord to twist up after you untwist. You never let it do that all the way. To me watching an expert turn something on a reciprocating lathe is the high point of the video. Always willing to take advice from an expert! And this, as they say in the USA, is not my first rodeo. Learned something from the video. Well done.
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