Thinking outside the shackle.

[john the pom]

Been thinking for a while now about how to obtain a rudder. I don't need one, I just want one because other people have one and it will help later on with a plan for a sail I have brewing. Could have bought a rudder kit but then I s'pose I could have bought a boat too. That just isn't me. It all hinged (bad pun intended) on sourcing a two-way pivot. Been racking my brains and believe me they need racking, on what to use that was: A, simple, like me, and B, cheap... also like me. :| Considered various bits of plastic plumbing, hinges, fabricating stuff that would enable a two-way pivot but that kind of endeavour would require work. (not at all like me )
Wandering around a hardware place dreaming about my two-way pivot when I came across a D shackle. HMM! As soon as I saw it I saw my two way pivot!
Criteria for it were twofold (another bad pun). It had to receive a mop handle which was always going to be the shaft of the rudder, and be of a size where the piece of wood I deliberately built into the stern of the boat would also be 'connectible'. The post at the stern of the boat will next be squared off vertically, narrowed a little and a groove cut vertically down the end to receive and restrain the mop handle, above and below the shackle. Then rounded off suitably at the top to allow an upward pivot. The tension bit I have worked out already. The whole thing will pivot on the shackle pin to retract/deploy.
You'll get the idea by now that my investment in componentry was not going to be huge. Shackle cost $3.00. If successful, or when rust appears I will upgrade to a stainless steel shackle. The mop handle piece just means my wife will have to lean forward a bit to mop the floor, hey she's not that tall. Grooves for shackle and cable ties cut with a round rasp. I cut the slot for the aluminium with a dremel cut off wheel, to the depth it would reach. Very tight fit, probably does not need cable ties to secure it but I will put them on anyway. The piece of aluminium I "acquired" on my travels. The only other outlay will be for 3 cable ties, one screw, suitable cordage, all of which I have, and a couple of rubber bands which will be the single most important part of my rudder setup. The whole wooden bit will be painted with polyeurethane paint, and where/if, the shackle wears on the shaft I'll just put a bit of linseed or cooking oil now and then. If I need to replace the mop handle part I'll just buy my wife a kneeling pad to do the floors with. :lol: Having seen the pic on the big screen I shoulda used my glasses when cutting the slots. I'll get the dremel out again. Things always look better without my glasses lately. :roll:
Still at the early stage of development and requires cleaning/tidying up a bit.

I reckon "Joel" nobucks would have loved this.
Ps The whole thing will be easily added and removed by unscrewing the shackle pin, for transporting
Cheers john

 

[john the pom]

Got a bit more done this arvo. At the stage now where I take it all apart clean it all up. Paint the bits that are gonna be painted. Oil the bits that are gonna be oiled. The hollow in the stern post and the groove at the shackle on the mop handle bit will just get oiled or silicon sprayed.
The elastic bands shown in the pic are a bit on the weedy side but it would work even with those! could even upgrade to a not too strong cable tie if I know I'm gonna be in water where it won't get snagged. The band pulls the whole thing into shape and while holding it in place still allows it to swivel as a rudder should. The tilted up rudder pic is what I would hope it would do if it hit a rock the bottom or a submerged branch.
It should then be pulled by the band back into place. That is the plan anyway. I've seen rudders that don't tilt up when I thought they should and figured it was worth adding the ability for it to do so.
The weak link that I can see is the plywood lever. Might even beef that up a bit more. I don't think the pull on it will tear the wood but the joint itself is only so so. I still have enough height to cut the top bit off and redo but I'll let it go for now.

The wife was out today and no doubt she's gonna ask what I did all day. Apart from modifying her mop, has anyone got any good comebacks for that?
Cheers John.

 

[Kayak Jack]

OK, guys. I'm passing the hat to collect a few bucks (Aussie bucks or Thai baht, of course) to buy that poor, long-suffering woman a new mop. I figure that $20 oughta hack it. :wink:

John, I've often wondered why boat rudders aren't more balanced. If the shaft were back, say a couple of inches, so some rudder blade was ahead of the pivot point but most of it aft of the pivot, the rudder would operate easier and still return to neutral when pressure (tension in the southern hemisphere) was released. History Channel lauded the ancient Chinese for ventilating (drilling large holes in it) there large rudders on large boats to relieve the pressure on the rigging to turn it. All they did was make a big rudder, and then make it smaller again. Moving the pivot point a bit closer to the center of area would have been simpler and more effective. They were close, but no cigar.

 

[john the pom]

Hey I didn't say the kneeling pad was just for cleaning the floors Jack!

"Though this be madness, yet there be method in 't"

. Have you not heard of multitasking?
I'm pretty sure I have read your thoughts on balanced rudders before KJ and I see your point and did consider it. Particularly in light of the neutral balancing act in case of a cable failure. Though I think it would want to go sideways and stay there as per Murphy's Law. It would have been quicker and simpler to run the mop handle through the saw and cut all the way through. This at the expense of removing more timber than by using a thin dremel wheel. The fit I got cutting with that was superb.
However, if the shaft is going to fail I think it will be from a splitting event rather than a snapping one. I have just rigged it temporarily and find that even with just one side of the cable if I pull it hard enough it will lift and almost clear the water. I just felt that by keeping more of the original structure of the wood that I could retain more strength. This setup is so damn cheap I might even go the extra few cents and try a piece your way just to test the theory about the strength. I think I would make the cut to above where the aluminium blade sits in then add a realy heavy duty cable tie or wire binding between the unoccupied area at thetop of the cut and the blade. Makes sense to me anyway.
Cheers John.
Ps I must have had my ancient Chinese eyes on when I was making the slots :lol: you were talking about.

pps I just tried it with a cable tie instead of rubber bands and it was rock solid. More so than any bought one I've ever come across.
I recently attended a canoe and kayak convention where there were dozens of top priced boats most with rudders. None of them were near as solid as this.

 

[Kayak Jack]

John, I applaud your design and your handiwork. You've done more than I have there. Good on ya!

Verlen Kruger shaped his rudders (made of sheets of aluminum from scavenged road signs - mayhaps even legally scavenged from a scrap pile?). He made them like a big, upside down comma, with the tail pointing up and next to the stern post, and the big, round part back under the water. The rudder post was attached to the upside down tail of the comma. That gave a semicircular shape at the bottom to ride up over obstacles. I don't know if that would function any better than a straight blade to provide lateral force or not. It was just another design and it worked for him.

He was constantly tinkering with design and redesign. The fellow who bought his rights and works will not change a thing from what Verlen had when he died.

 

[john the pom]

This one is only a rectangle shape at the moment. I do intend trimming a bit off here and there. It just happened to be the way the piece of aluminium came into my possesion. Any bit not in the water will be angled down and the bottom edge will also be given a curve to create a leading edge that hopefully will assist with lifting if it strikes a mermaid.
I own a fine $0.00 saw table that I just bolt onto a power saw, care of someone crashing into and dislodging a "keep Right" sign. You Mericans would probly be more familiar with "keep Left" I'd suppose. I just "keep stuff" I might find useful one day. Last week I bought a new bbq, the door was damagd, after I had finished abusing the salesperson and demanding they get a new one out to me asap (they did by courier two days later). Well the scratched door might just become a router table.

Cheers John.

 

[Kayak Jack]

You're a hoarder and tinkerer of the first rate, John. We may be shirttail relation back a ways? When my Granddad died, he had a brand new head gasket for a Model T hanging on his shop wall.