How to Use an Autotiller Autohelm on a Wheel

[xluke]

Hello,
I searched and searched for this solution until I created it myself with the help of some others from these boards.
I thought I would share these photos for anyone wanting to use their autotiller autopilot on a wheel steered vessel. The reasons for such a rig are numerous and include upgrading from a smaller tiller steered boat or having a backup to a dedicated wheel autohelm on the cheap. The autohelm works well on the wheel though range of motion is limited it is able to steer a well-balanced boat without difficulty. So far I have used it for 30 minute stints in 15 knot breezes close hauled and beam reached as well as under motor. I increased the rudder gain on my raymarine st1000+ to "7" from the "4" that I used when it was on a tiller so that it would make enough adjustments to not need to turn the wheel a lot given its relatively small stroke. I'm using it on a San Juan 28 with a displacement of approximately 6500lbs and lots of sail area.

Attaching it to the wheel is simple. Take a piece of wood and attach it to the wheel with u-bolts (stainless steel from lowes or home depot). Then install the autohelm tiller pin as pictured in the center of the wood. Make sure that the wood is angled so that when it is going towards the autohelm it will not interefe with the body of the autohelm. Then come up with some way to attach the autohelm body to your boat. I opted for a simple system that is quick to take down using some line and a shaped piece of wood that interfaces with my binnacle cup holders.
Keep in mind that the autohelm needs to attach to the top half of the wheel for it to think its going in the right direction. Also, for those needing a new autotiller thimble (where the autohelm body attached to the boat), you can get them at lowes for $2 instead of paying raymarine $20 -- they are standard 3/8" inner diameter bushings. Also, the tiller connectors are available from westmarine in a pack of 5 for $10.

Good breezes!

[Capitain Mike]

I like it well done

[atoll]

nice woodwork,you might be also interested in,(since the invention of the wheel),raymarine have also invented somthing called a"wheel pilot"............10out of 10 for ingenuety........

[txg]

Did anyone else try this out? Perhaps with some nicer woodwork?

I did some calculations:

ST1000+ on a tiller, correctly mounted (460mm distance from rudder stock) and with 125mm travel in each direction means a rudder angle of about 15° from centerline.

My Dufour with wheel steering needs about 1.25 rounds to move the rudder from 0° to about 45° (that's a guess). The wheel pilot will be able to move the wheel about 45° in each direction without losing too much power. This means the maximum rudder angle will be about 9° from centerline.

While not as bad as i expected, the result is not too god.

So are there some more practical test results from anyone else?

The other possibility would be to use a line and a drum as used for windvanes. That should work without any problems, but the Installation is not as easy. For my boat, the drum should have a diameter of 19cm.

[colemj]

What is the throw on that? It doesn't seem like it could turn the typical wheel/rudder ratio more than about 4-5 degrees of actual rudder.

Is the force on that really being transferred to a plastic drink holder?

Mark

[Reiziger]

I think its more easy to make it work with the use of a cheap to buy used Truck/Bus Windscreen Wiper Motor.



CeesH