I have been using the little Hitec HS 5086 WP as a rudder servo for sometime now; mounted directly on the rudder shaft on my "Alternative" IOM and fully external on the last Mini40 Trimaran. Currently putting a Mini40 Cat together and would really like to use a WP winch or arm. Does anyone know of such a beast ? The loads on the multihulls are not as great as the IOM so that sort of defines the torque requirement.  Any advice greatly appreciated.

Richard

Richard

i will have a look at which servo I ordered to convert to an arm winch. It was off ebay. The servo is supposedly water proof as its intended use is as a steering servo for rock crawlers. These are available as standard size servo's with a torque range of 35 to 45 kg/Cm. As this is to be fitted under deck on my boat the waterproof bit is a bonus.

I started this as I wanted a spare / replacement for the arm winch fitted  in my Britpop which is a Hitec monster power item. The Hitec that is fitted does not seem to be available any longer and it's replacement is the wrong side of £150. (You also need to add the cost of a servo programmer) The one's off ebay vary in price from £15 to £30 plus you need to add the cost of a servo expander to this to enable 180 degrees of travel, I think I paid about £8 for two of these. You will also need a pulley block to fit to the arm to give you double pull. I think the spindle splines on the ebay winch matches that of the Hitec so I could use the existing arm.

As the Hitec is still working OK I have not tried it out in a boat but have built it up with a new carbon arm (active length of arm approximately 90mm) and tried it outside the boat and seems alright. Used the radio to tune rotation of servo to about 160 degrees to obtain length of pull needed.

I have been communicating with another skipper who has also been experimenting with these and he has fitted them to a number of new builds. (IOM's) with successful results.

If you want a chat just give me a call.

Eric

There are lots of waterproof sailwinches about.  If you want cheap and cheerful try Kingmax

https://www.componentshop.co.uk/68g-digital-sail-winch-servo-6-turn-programmable.html

Or for something better try the new Red Ant 

https://redantradioyachts.com/electronics/  

I know everyone swears by RMGs, but I am not a fan as I think the geartrain is very poorly engineered (lots of slop) and they are not waterproof.

Most servos will have enough torque for the job (RMGs have arguably too much!), the big differences are in speed of operation.  You can get round slow servos up to a point by anticipation but speed is useful for gybing.

Thanks Eric & John.

The 68G WP winch seems unavailable anywhere; shame since I use the 61G and have found them very good. That sort of rules out a drum then. However there are a number of 20/25/30 Kg WP servo's out there, as you say Eric. Cheap too !  DS3225 seems to have loads of reviews and info and the added bonus of 180 deg travel. Compatible with a Futaba arm (25T). So that seems the simplest solution. Thinking 85mm rad at 120 deg travel.  Will mount both servo's in the open, on a bracket, on the for'd Cross tube. Just need a small enclosure for the Electrickery lashed onto the aft cross tube. Going to be an odd looking beast !