Wheel steering drum rope turns

[Ian R]

Hello-

I am making a wheel steering set-up for my 31'. I have made it from offcuts knocking about my workshop (hard to get stuff at the moment)  and to suit my tooling (small engineering lathe/woodworking gear), so haven't bothered looking at plans.

The drum is 200 long x 150 diameter laminated elm with 6mm thick tufnol discs 200 diameter at the ends, on a 25mm bronze shaft/stainless bearings.

I have set it up on the bearings which are housed into shells housed into the ends of a thick ply box and have been playing about with it at this stage to see how the rope will behave on it in use. The drum spins well and true but from what I can see the rope will form riding turns if it is just wrapped along the drum. So is the rope fixed in the middle, or arranged in some way to stop riding turns? How many turns are best used, should they cover the length of the drum? I am assuming 5mm or 6mm diameter dyneema will be used as I have some spare.

Any advice? Thanks-  Ian

[Ian R]

For the record I've spent a few (more) happy hours trawling the back pages here and elsewhere, and eventually found this:

On here Mike Lynn said that the Wharram set -up on Pahi 42 was 3 turns each direction, 5  drum turns lock to lock. Photos seem to indicate two narrow drums are used side by side.

Ann Clement said that Neville had fixed up a tufnol drum reclaimed from something else, fixing the rope in the middle and a couple of turns each side, and using waterpipe (I guess the blue mains- water pipe  is very low friction) for directing the rope, presumably to the blocks.

Elsewhere (monohulls) I have found people using a divider on the drum and others winding the rope fixing it in the middle.

It would seem that an easy- access facility to deal with any problems is a good idea. I am also leaving the tail end of the shaft coming out the other end of the housing  opposite the steering wheel overlength for anything else I decide to put on it ( but can always saw it off if it gets in the way).

[Ian R]

Ref wheel steering for Tiki 31 I mentioned last year: I had it set up quite well last summer and had to dismantle it for the winter when I wrapped the boat up  - with an all-over plastic tarp tent slung between the two masts and extended to stem and stern needing the tiller bar off-  the cover was very effective, survived  some F10  s  on the dock (two  !0m x 6m tarps full length rope- laced at centre-line, slung from the masts @ 2m high from deck).

When I set up the steering again recently the 5mm line slipped on the drum and I couldn't work out why. Then I realised the turns weren't  really tight on the drum even when I increased tension on the tensioning block and tackle set.

The solution was to crank the drum line/steering line bar- tight and locked solid FIRST  with the tensioning set then release the tension to a workable state: the turns of dyneema stayed tight on the drum with no slack and did not slip when dry or wet. I have 6 turns of dyneema on the drum.

Cheers  -    Ian

[Ian R]

Hello-

For the record on the Tiki 31 and anyone building or sailing this boat: I have recently completed a non-stop 3.5 day voyage from Fosdyke Lincs.  to Dartmouth including running into Dartmouth on jib only on an F7-8 easterly.

The wheel steering performed 100% and there was no slippage with the dyneema.

The only time we used the tiller bar for steering was getting onto the pontoon up the Dart, because you can access the outboard throttle from that position and at present I have no remote while I decide whether or not to keep my Tohatsu 20hp with very long leg, or change to a lighter outboard.

Not much cavitation with the Tohatsu 20  but I have to have a four-part block and tackle across the centre deck to raise the sled: the Wharram raising rig must be for toy motors - in no way can it raise that anyway.

In my view the wheel steering is essential for the Tiki 31 and I will post details of the design in due course.

Cheers - Ian

[Ian R]

Hello- I am a bit of a luddite with computers but will attempt to upload some photos of my wheel steering for the Tiki 31.

This is the boat self-steering with balanced sails off Brighton in July. The drum frame is bolted to the oak frame below which is lashed to a subframe below which holds the whole rig on the cockpit seats. Fully demountable without trace in about 3 minutes. If this one works I will add some more.

Cheers   Ian

[Ian R]

Ian R said:

Hello- I am a bit of a luddite with computers but will attempt to upload some photos of my wheel steering for the Tiki 31.

This is the boat self-steering with balanced sails off Brighton in July. The drum frame is bolted to the oak frame below which is lashed to a subframe below which holds the whole rig on the cockpit seats. Fully demountable without trace in about 3 minutes. If this one works I will add some more.

Cheers   Ian

[Ian R]

Tiki 31

[Ian R]

Tiki 31

[Ian R]

Tiki 31

[Ian R]

You can see from the photos a 4 part tackle going across the accoya deck: that is to raise the Tohatsu 20 -it only just does it. As I said before, the Wharram sled raising details do not work for my (heavy) motor.

This winter I will design something better to raise it with as the block/tackle across the deck is a trip hazard, among other things.

[Ian R]

Here is another photo showing wheel steering from Tiki 31 cockpit : Tiki 31 built as designed by Wharram/Boon - quite small alterations only to plan details, such as centre deck, sliding hatches, ommision also of aft ramp (not shown).