Splice Joints

[Alixander Beck]

Any suggestions on jigs or techniques to cut a splice joint?

the application of this joint will be similar to its use in a cricket bat but will be applied to canoe paddles.

http://www.wipo.int/ipdl/IPDL-IMAGES/PCT-IMAGES/01022007/GB2006002780_01022007_gz_fr.x4-b.jpg

[P.I. Stazzer-Newt]

I have seen a large number of paddles - built more than a few - and never seen that attempted - what do youe see as the potential advantage over the usual approaches?.

[Bruce Hooke]

Are you trying to make the joint once or twice or are you trying to make the joint on a production scale? If the former, then I don't think it will be that bad a joint to make using power tools at the start and hand tools to finish it off. If you are trying to make the joint on a production basis then you'll probably want to put a lot more time into figuring out what sort of jigs you need to make the joint using power tools for as much of the work as possible.

[Pericles]

The reason for splicing the handle into a cricket bat is functional. There are shock absorbers in the handle so that the batsman can return a leather encased ball that could be arriving from the bowler 22 yards away, at a speed in excess of 95 mph. The crack of willow on leather is not a description of a gentle game. It can be war out there.

Somehow, I do not see the need for splicing the handle into the paddle as the forces generated are unlikely to match cricket. Now, if you were making oars? Nope, sorry but if splicing offered an advantage, Oxford and Cambridge would have gone for them.

Please, please, do not tell me they have spliced oars. I could not stand the shame and mortification of being so wrong!:D:D:D:D:D

Pericles

[Bruce Hooke]

It could certainly make a visually interesting canoe paddle if contrasting woods were used, and I don't see any need for further justification for the joint as long as it does not create other problems. I'd be more concerned about the hollow shaft, if that is part of the idea. You actually want some flex in a canoe paddle and I think a hollow shaft might work against that by creating a stiffer paddler for the same strength. Actually, if the goal is a racing paddle I am not sure if extra stiffness is an advantage or not, I just know that for paddling all day a bit of flex in the paddle does seem to be considered desirable.

[Alixander Beck]

I have seen a large number of paddles - built more than a few - and never seen that attempted - what do youe see as the potential advantage over the usual approaches?.

the first potential advantage is what you have eluded to above. I have never seen this either therefore in my mind it should be attempted.

second potential advantage is ability to use different woods for paddle and shaft to capatialize on different wood properties.

third potential advantage is aesthetics

[Alixander Beck]

It could certainly make a visually interesting canoe paddle if contrasting woods were used, and I don't see any need for further justification for the joint as long as it does not create other problems. I'd be more concerned about the hollow shaft, if that is part of the idea. You actually want some flex in a canoe paddle and I think a hollow shaft might work against that by creating a stiffer paddler for the same strength. Actually, if the goal is a racing paddle I am not sure if extra stiffness is an advantage or not, I just know that for paddling all day a bit of flex in the paddle does seem to be considered desirable.

Agreed, the visual component make this a worthwhile attempt. There will be no design for a hollow shaft, shaft flex is a neccesary feature of a paddle.

I don't make racing paddles, mine are built for longer trips which need flex and don't see the same amount of loads a racing paddle would.

[Alixander Beck]

Are you trying to make the joint once or twice or are you trying to make the joint on a production scale? If the former, then I don't think it will be that bad a joint to make using power tools at the start and hand tools to finish it off. If you are trying to make the joint on a production basis then you'll probably want to put a lot more time into figuring out what sort of jigs you need to make the joint using power tools for as much of the work as possible.

it's for production.

[JimConlin]

Sawyer canoe paddles are made in this way.
http://paddlesandoars.com/images/paddles/enlarged/youth_spy.jpg

The blades are thin stock set into a slot in the shaft. The blade assembly is lightly glassed. Nice paddles.

[Alixander Beck]

interesting. thanks!

[Bruce Hooke]

Figuring out a way to do it on a production basis is an interesting challenge. My first thought is a router jig. One approach would be a piece of Masonite with a V-notch cut in it to guide the router using either a template collar or a template router bit with a ball-bearing on it. You would need cradles and clamps to hold the shaft and the blade in place. If you went this approach it would be easiest if the top of the point in the joint was rounded over a bit. Otherwise you would need to finish the V-notch by hand. Also, the template would be very fragile if it had to come to a sharp point. If a sharp point is essential to the look you are after then it might make sense to reinforce this part of the jig with metal.

It might end up making more sense to make two jogs, one for the end of the shaft and one for the blade. One template would mean you could cut both sides of the joint in one pass, but I suspect that what you would gain in speed at this stage you would loose in terms of the time it would take to "load" the jig, and also in terms of how make care it would take to use the jig. If the router bit is cutting both sides of the joint at once then you have to pick which side of the guide slot in the jig to use as the reference, and you'd have move the jig carefully, especially as you went around the tip, to keep the ball-bearing or the template collar against this reference edge.

[P.I. Stazzer-Newt]

I've used hollow shafted kayak blades - an italian maker called "Azali" used to do them - They were OK but not an improvement on a conventional set in well chosen timber.

The amount of flex depends almost entirely on the outside diameter of the shaft - a hollow shaft of the same OD is slightly more flexible (less stiff) than a solid one.

McGruers of Rhu used to make hollow wooden shafts that are things of legend - but I've not met a real one - made from quarter cut spruce.

[Bruce Hooke]

The amount of flex depend almost entirely on the outside diameter of the shaft a hollow shaft of the same OD is slightly more flexible than a solid one.

Yes. To clarify I should say that I was assuming the hollow shaft version would be a little bigger in diameter to achieve equal strength.