Pole Lathe

[VO5]

In an attempt to fend off, SWMBO, to steady herself, got hold of the Ensign Staff, and Hey Presto ! ....She snapped it off....

As the Ensign is a Full Yard, the staff has to be long to clear several impediments on the stern rail so that the edge of the flag does not get frayed.

All the Ensign Staffs I have found are either too short, too fat, or both.
I have hunted in the vicinity for a carpenter's workshop capable of turning a new one for me. No luck.

So in desperation I have gone to an extreme and I have built myself a pole lathe.

For those of you who have never seen or heard of one, this is an antiquated but effective way of turning out furniture legs, finials, bannister supports and suchlike. It is the precursor of the modern woodworking lathe.

Unlike the modern counterpart which is motor driven, this contraption turns the wood into a cylindrical shape by foot power using a treadle arrangement.
The work, a long peice of wood, first of all is cut in square section.

Then a four bevels are cut to make 8 sides on the work and then it is suspended between centres.

Above the bed is a springy length of bamboo to which is tied a thin line. This line is wound round the work and is then connected to a treadle.

The action of the foot depresses the bamboo and causes the work to rotate.
On relaxing the foot pressure the bamboo springs back to its original position of rest, causing the work to turn the other way.

And so, by activating the treadle, the work is made to rotate back and forth, back and forth.

Using a rest, a chisel is presented to the work, (when it revolves towards)
first of all to rough cut. Then progressively the work begins to take on a cylindrical shape.

As the staff has a taper more needs to be cut from one end, by gradual increments. Once the Staff is cut then it is smoothed with very fine sandpaper, the cap glued on and the finished work varnished. It sounds easy, but it is a lot of work.

Have any of you readers ever attempted such a mission ?

The staff is 52" long. Phew !

 

[Rigger Mortice]

Brilliant use of old technology! Don't forget to make a second staff so that SWMBO can break it again.

 

[VO5]

Brilliant use of old technology! Don't forget to make a second staff so that SWMBO can break it again.

How did you know that ?

I am actually making two, not one.
I have already made the caps 1 3/4" in diameter, with the hole for the tip and complete with slot and tiny sheave.
Now also I am making the little cleats out of the same hardwood, to match.
...Doesn't sound like much, but it is a job and a half...and wood shavings everywhere, SWMBO very pleased...and mugs of tea and sweeping provided..

 

[agurney]

I have a Wolf craft lathe, I don't know if they are still available. The head/tailstocks are separate components that are clamped to a bench (or 2), and the whole is turned by an electric drill. Very easy and effective.

 

[VO5]

I have a Wolf craft lathe, I don't know if they are still available. The head/tailstocks are separate components that are clamped to a bench (or 2), and the whole is turned by an electric drill. Very easy and effective.

The question is...what about the T Rest for the graver, how do you set that ?
I overcame that problem by fitting a square section iron bar in front of the work so I can slide the cutting chisel (used as a graver) along by hand.

 

[agurney]

The question is...what about the T Rest for the graver, how do you set that ?
I overcame that problem by fitting a square section iron bar in front of the work so I can slide the cutting chisel (used as a graver) along by hand.

The rest is on a swivel on yet another cramp, you can turn about 8" before it needs to be reset.

Picture of bits here: http://tinyurl.com/6ewjycw

 

[agurney]

How did you know that ?

I am actually making two, not one.
I have already made the caps 1 3/4" in diameter, with the hole for the tip and complete with slot and tiny sheave.
Now also I am making the little cleats out of the same hardwood, to match.
...Doesn't sound like much, but it is a job and a half...and wood shavings everywhere, SWMBO very pleased...and mugs of tea and sweeping provided..

Apart from the obvious composting, wood shavings are useful:
- they make a great polish; when you think the staff is as smooth as you can make it, take a handful of shavings and grab hold of the staff and keep turning.
- use some in a smoker for mackerel

 

[VO5]

Apart from the obvious composting, wood shavings are useful:
- they make a great polish; when you think the staff is as smooth as you can make it, take a handful of shavings and grab hold of the staff and keep turning.
- use some in a smoker for mackerel

....Makes sens.. I know an old furniture restorer who polishes mahogany to a mirror finish by using sawdust held down in two sheets of kitchen paper...back and forth along the grain..he happens to have a wood turning lathe but the distance between the centres is 20" max. So I have had to make my own pole.

 

[prv]

Picture of bits here: http://tinyurl.com/6ewjycw

Cheers - looks like the kind of thing that could come in handy so I've put a speculative bid on

Pete

 

[prv]

Then a four bevels are cut to make 8 sides on the work and then it is suspended between centres.

In case I don't win the auction for the Wolf set...

What do you use for centres on an improvised lathe like this, and how do you get them to hold a 4-foot stick securely?

Pete

 

[TQA]

So you are a bodger now ehh!

 

[Graham_Wright]

I use a stainless tube. With a centre cockpit, it doubles as an emergency tiller.

 

[electrosys]

In case I don't win the auction for the Wolf set...

What do you use for centres on an improvised lathe like this, and how do you get them to hold a 4-foot stick securely?

Pete

If not already 'sussed' - try skate-board wheels ....

They work when turning spars.

 

[Wunja]

The trouble with turning that length down to a small diameter, is that it can flex in the middle as you push the tool against it. Of course if SWMBO is going to use it as a grab handle a large diameter would be advantageous.
Personally, I would use a spoke shave to round off the octagonal section.

 

[snowleopard]

One problem with a pole lathe is that the return stroke rubs the edge and blunts it so you shouldn't use the same technique as you would on a power lathe. Ease the blade back slightly for the return stroke and forward for the cutting stroke. It's worth going to some trouble to arrange a steady tool rest reasonably close to the workpiece.

 

[Quandary]

I can't agree with the bamboo pole either, go out the back and cut a nice length of green hazel, the longer the better, extend the treadle as long as the power in your legs will let you so that you get a long steady motion rather than a fast jerky one. The 'green woodworkers' around here are using these all the time when they are evangelizing, but they do it out of doors so that the length of the pole is not restricted by headroom. I suspect for an indoor one unless you are in a barn it might be better to tie a length of shock cord to the ceiling.

 

[VO5]

Nope...I have given up the pole lathe idea.
I just cannot get it to go.
The work can be suspended between centres without a problem.
I have consulted dimensions for a pole lathe design and it is a huge undertaking.
So I am resolved to do it with a plane because, even though I own two spokeshaves, I don't currently have access to them. What a bother !
I will let you know how I get on.

 

[ChattingLil]

my ex husband is a both a wood turner and a green woodworker. He has been pole-lathing for 20 years. Believe me, I am not saying this out of loyalty, but he is very good. He's based in Woodbridge. If anyone needs anything like this and is fairly local to the east coast, let me know and i'll put you in touch.

 

[VO5]

In case I don't win the auction for the Wolf set...

What do you use for centres on an improvised lathe like this, and how do you get them to hold a 4-foot stick securely?

Pete

Ok, I will explain....

A pole lathe is the name given to a manually rotated lathe arrangement for turning wood and goes back to as early as 1666.

In reality it is a large version of what is known as "Turns", which came a little bit later.

Turns are different to a conventional lathe, because a conventional lathe is either pedal or motor driven, and, the work is made to rotate one way only, whereas the turns are operated using a bow causing it to turn to and fro like a pole lathe. Turns are used in classical watchmaking. (for making balance staffs, studs, pivots and screws)

To give you an idea, the distance between centres is not very great, only barely two inches. The size of the turns is between say, 8 to 10 "" long and for small ones 4" to 6" long, for very delicate and precise work.

The bow is fashioed out of very thin bamboo and the thread is silk, and for some work, waxed.

Therefore whereas in a lathe the work would be held in a chuck and supported at the other end by a tailstock, in the pole lathe and turns arrangement the work is suspended between centres, effectively two tailstocks facing each other..

The problem when turning between centres is not to allow the holes at each end of the work to become enlarged or ovalised.

To overcome this problem, I drilled a small hole in the centres of two coins, straight through. These holes were then re drilled as countersunks.

A coin was glued at each end of the work and the centres sharpened to a point., then lubricated. As the points are at the ends of screws, if wear develops, the effect of this wear can be corrected by tightening the screws fractionally to eliminate play.

This ensures avoiding problems of sideshake (when the work rattles as it wanders from side to side) and endshake(when the work drifts from end to end.

Another consideration when turning long thin material is the risk of it buckling in the centre. For this a supporting rest is used that has a roller that helps to support the work from behind, eliminating (with skill) that risk.

Does this explain what you wanted to know ?

 

[VO5]

The trouble with turning that length down to a small diameter, is that it can flex in the middle as you push the tool against it. Of course if SWMBO is going to use it as a grab handle a large diameter would be advantageous.
Personally, I would use a spoke shave to round off the octagonal section.

Yes exactly.
In my previous post I describe how in miniature work the support is offered from behind to prevent buckling.

It is a very precise component of the skill sets required in classical watch and clock work.

Just to give you an idea of how sensitive it is that the larger turns are powered by a whalebone bow and horsehair . The smaller ones as described above.

The problem with a pole lathe is that the force to drive the work (of this size)must be adequate.

The construction of such a huge contraption just to turn two staffs is not worthwhile, so I will be resorting to paring rather than turning, first using a plane, followed by using a spokeshave.