Tapering Wooden Poles

Roach1948

Roach1948

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www.dallimoredesigns.nl
I would like to know how to taper a pole (like a spinnaker pole). I say “like” because what I would like to do is taper 4 legs for a table I am building. I would like to make the tapers quite pronounced. I have very limited tools but I do have a block plane and a detail sander and cork block. Each table leg to be approx 80cm long, maybe 8cm at the widest point and 4 cm at the end of the tapers. I can get hold of a hand saw. Anybody got any ideas to get me started?

Many thanks,
 
Round and tapered or square with tapered sides?

Round is easiest done with a router or lathe but square and tapered can be sawn, table saw is best but you could hand saw and plane.

Alternative traditional way to do round is to cut it square, 4 sided, then make it 8 sided, then 16 sided, than plane the almost round shape to suit. I've got it one of my books but can't remember which one.

Googled it - using a spar gauge to turn square timber into round Spar Gauge

More useful stuff: Woodenboat.com
Amateur Boat Building

Good section in here: Making tapered paddles

and do a google for "Clinker Plywood Boatbuilding Manual By Iain Oughtred" and you'll find a preview showing really clear photos of the process.
 
One of these is handy



logs003.jpg



Or as said above work down the sides untill you have the shape you want .
 
I was thinking of your kit when I wrote the reply but "just ask Cuchilo to make you one on his fancy router" was too easy when he wanted to do it himself without powertools.

Somewhere I've got a really good write up on making masts and booms in hollow with tapers but just cannot remember where it is, old age and too much decorating taking its toll /forums/images/graemlins/smile.gif
 
[ QUOTE ]


Alternative traditional way to do round is to cut it square, 4 sided, then make it 8 sided, then 16 sided, than plane the almost round shape to suit. I've got it one of my books but can't remember which one.



[/ QUOTE ]

That's the way to make tapered spars - and is actually easier than it sounds, a spar gauge can be quickly knocked up from an offcut of wood and four nails
 
A spar gauge is more usefull for varying tapers. For Roach's little legs, mark the rounds on each end and get planing. Check with a straight edge when getting close to the marks. Personally, I would find a circular or band saw to rough them out, or set up a hand drill as a lathe.

A
 
Once you have set the taper by sawing it square, the spar gauge follows the taper and marks for the octagon. As your taper is constant, a straight edge from marks on the end faces will serve.
A
 
Just a comment, birdsmouth spars are tapered by planing the staves before glue up. So not relevant here. ( I shoud know, I made all mine by this method, and have three more to do...)
A
 
You can still birds mouth a tapered edge but thanks for the wood work lesson /forums/images/graemlins/grin.gif.

Actually Roach a mitre lock cutter in a router table may well do this kind of method for you .
 
This is one of those occasions when a picture is worth a thousand words. I'll have to settle for a thousand words. A spar gauge is a length of 2"x1" timber with two 4" nails through it set on the centreline. They are spaced apart a little more than the maximum width of the spar. The nails rub along the side of the spar as you draw the gauge along it. To keep the nails in contact with the sides, increase the angle between the gauge and the spar centreline as you go. Between the two nails are a couple of holes to take wooden pencils. The spacing of these is important. At the wide end, draw a couple of diagonals from corner to corner, which will give you a centre point. With your compass pin at the corner and the pencil at the centre point, draw arcs out to the sides. Do this for all sides. Join the points on the sides to show the ocatgon that you need. These points will give you the spacing for the pencil holes on your spar gauge. Do this for both ends. Draw lines parallel to the sides of the stock and tangential to the circle to give you the inital taper square section to saw to. Run the spar gauge along the tapered stock to give the lines to plane to to get your octagonal section. Hand-plane to 16 sided, and then to round by eye.
Peter.
 
This wil raise a few comments and arguments I'd guess, but do be careful using a spar gauge on a taper. It won't actually be accurate on a taper. As long as the taper is long and fine, then the error is generally negligible, but it is there. With a shortish gauge and a long taper, it will be far less than the error found in pencil marks and hand finishing; but if the tapered length is only a few times longer than the width of the gauge, then I'd suggest using another method.

Just use the 7:10:7 ratio that the gauge works on, but measure it out by tape, and draw it with a straight edge instead.
 
Is it possible that you want to calculate the "camber"? This is the amount of curve that will provide a curved taper rather than a straight taper.

If so please PM me and I will talk you through the calculation.

Regards

Simes
 
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