Homemade wheel drum for wind vane

[sailor1924]

Originally Posted by seasick

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We had a 4-turn peg to peg worm gear steering system and so used a 2 to 1 block system with cleat similar to what jmrod describes. An inch of pull from the vane resulted in 2-inch pull on the pulley.

If you can find an old Nordic Track on the 2nd hand market they incorporate a robust, 6-inch, nylon pulley that is ideal for making a clutched wheel drum or one that is fixed with a pin.

The diameter of the drum is critical and should be in the neighborhood of 6" to 9" depending on your turns peg to peg.

A bicycle rim at 18"+ as S/V Beth used is too large a diameter. The power of these servo-pendulum vanes is easily enough to rip the wheel from your hands at six knots with a 6" pulley.

Seasick;

I'd like to pick your brain a bit if possible.

I too have a worm gear 4 turns lock to lock. I've just installed a Voyager windvane with a line travel of about 10" total, I'm planning to make a wheel adapter. Do you have a photo of the connection from the vane tiller to the block doubling the the line travel? Or can you diagram the line setup? I'm visualizing a system where the wheel is attached to a movable block and the vane tiller pulls on the block. Is that correct?

What did you find to be the right diameter for the adapter. Also did you ever prototype the adjustable diameter wheel adapter you mentioned?

[Jim Cate]

@RaymondR, I too have used a stainless frying pan for a pilot drum and a windvane drum. With mine, I roughed up the pan with sandpaper, laid on an 1/8" coat of epoxy putty all the way around then coated the belt in Vaseline and carefully wrapped it around the pan. Once the belt's impression was left in the putty, the putty was left to harden. Voila, DIY timing belt pulley. Works great for a pilot or attach your vane lines to a broken belt for the vane.

Another approach for this is to glue a piece of broken belt to your drum, tooth side out. Mates perfectly with a drive belt or, as mentioned, another length of belt attached to the drive lines from the vane Zero slippage, ever!

Jim

[UNCIVILIZED]

Originally Posted by Jim Cate

Another approach for this is to glue a piece of broken belt to your drum, tooth side out. Mates perfectly with a drive belt or, as mentioned, another length of belt attached to the drive lines from the vane Zero slippage, ever!

Jim

Good tip, I had a similar thought. Especially since I was fond of belt driven motorcycles as a teenager.

[RaymondR]

You might also have a look at the plastic wheel barrow wheels in a hardware shop, some of them are 6" - 8" diameter.

[Jmord]

My homemade wheel drum worked well. It is about 8" in diameter and consists of a circle made of 3/4" plywood sandwiched with 1/8 inch plywood circles on each side. The thinner pieces have a slightly larger diameter to provide a 3/4" groove for the steering lines to rest in. In the groove, I used rubber cement to glue a strip of bike inner tube. This provided grip for the steering lines. In addition there is a small cleat on each side of the wheel drum. I found it helpful to cut the steering lines once they enter the cockpit and reduce them to paracord.
We travelled 1500 miles this year with this setup and I'm very pleased with it.
I hope this is clear... Sorry I don't have pictures for you.

[sailor1924]

Originally Posted by Snowpetrel

Another benefit of a home made one is that you can get the diameter of the drum just right, to get the best ratio for your system.

I've considered making an adjustable wheel adapter with 6 or so shaped blocks that can be slid in and out to adjust the diameter of the drum.

They could be attached direct to the spokes, or to a plywood drum that's then clamped to the wheel.

Getting the right relationship between pendulum movement and rudder movement is a big problem with many servo pendulum to wheel systems because it varies with different boats. This is part of the reason it can be so hard getting a servo pendulum system to work well with a wheel. Much easier to get this spot on with a tiller.

Sent from my HTC_0PCV2 using Cruisers Sailing Forum mobile app

Snow Petrel;

Sorry I attributed your idea about an adjustable pulley diameter to Seasick.
If you have built it or have drawings I would love to see them.

[Snowpetrel]

Originally Posted by sailor1924

Snow Petrel;

Sorry I attributed your idea about an adjustable pulley diameter to Seasick.
If you have built it or have drawings I would love to see them.

I haven't made one. I have used a tiller so far with my wind vanes and it is easy to adjust the ratio by shifting the lines in and out alomg the tiller. I envisaged a delux system for a wheel along these lines.Sorry about the scrappy diagrams.

The 1st plywood disk attaches to the wheel with saddles or similar. It has the hub, made from low friction material. That the drum spins on, and holes around the perimeter to lock the drum part with a pin. The 2nd and 3rd disks form the drum unit. The 2nd disk has matching holes for the locking pin. The spacers form the drum part that the rope wraps around and can be shifted in and out by dismantling the drum, unscrewing them and shifting them in and out until you are happy with the ratio.

It may well be possible to simplify it and just have a cleat attached to each spoke and slide them in and out to get a rough idea of the correct ratio. Once you know the correct size you can make something much nicer.

It takes a while to find the right ratio. It will be a compromise. What you want for fast downwind will be different from windward work in gusty conditions. Over time you should find a decent compromise. Or at least I always have with my tiller systems. But sail in a variety of conditions for a while before locking it in. .

[sailor1924]

Originally Posted by Snowpetrel

I haven't made one. I have used a tiller so far with my wind vanes and it is easy to adjust the ratio by shifting the lines in and out alomg the tiller. I envisaged a delux system for a wheel along these lines.Sorry about the scrappy diagrams. Attachment 148724

The 1st plywood disk attaches to the wheel with saddles or similar. It has the hub, made from low friction material. That the drum spins on, and holes around the perimeter to lock the drum part with a pin. The 2nd and 3rd disks form the drum unit. The 2nd disk has matching holes for the locking pin. The spacers form the drum part that the rope wraps around and can be shifted in and out by dismantling the drum, unscrewing them and shifting them in and out until you are happy with the ratio.

It may well be possible to simplify it and just have a cleat attached to each spoke and slide them in and out to get a rough idea of the correct ratio. Once you know the correct size you can make something much nicer. Attachment 148725

It takes a while to find the right ratio. It will be a compromise. What you want for fast downwind will be different from windward work in gusty conditions. Over time you should find a decent compromise. Or at least I always have with my tiller systems. But sail in a variety of conditions for a while before locking it in. .

Snow Petrel;

Thanks for the drawings and the description.
I've seen a photo of the Cape horn wheel adapter which appears to be similar to your use of individual cleats on the wheel spokes. Also one of the old bronze Aries wheel adapters look like it might be adjustable in a similar way. Do you think the operating force transmission would be "jerky", i.e. have a sticking point where it changes direction at each spoke?

[Snowpetrel]

http://www.capehorn.com/sections/pag...sonanglais.htm

Interesting. Nice find on the cape horn unit, this link shows a similar idea to my second drawing, but much smarter. He also talks about the ideal ratio being near two to one, as in 20 deg of servo movement for 10 degrees of rudder movement?

When I've tried a fools purchase to increase the helm movement it has added too much friction, and you are limited in the 'gear' ratios you can use. Hence me thinking that cape horn have it right with their adjustable wheel adaptor unit.

I don't think the slight jerkiness would be an issue, but if it was a problem you could make up a disk and add as many blocks as you wanted to smooth it out.

Once you have the ratio nailed you can make a smart one out of whatever you want.

[Snowpetrel]

Here is another neat solution.

[sailor1924]

Originally Posted by Snowpetrel

Here is another neat solution.

You found the photo I had referred to as an old Aries wheel adapter.
And thanks for the high lighting Cape Horn's description of the ratio of pendulum movement to rudder of 2 to 1. The Voyager vane I have allows the attachment point on the pendulum tiller to adjust the radius from the axle of the pendulum to the actuating lines to the wheel as I believe an attempt to adjust the ratios of line travel.
I'm wondering if the Cape Horn's use of a quadrant to actuate the vane creates a sort of parabolic arc of movement that allows the line travel to maintain the 2 to 1 ratio through the full arc of movement. And so; between the quadrant and the adjustability of the wheel radius a sweet spot can be achieved?