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A600: Servo selection


Like many other RC models (planes, boats, etc.) this kit does not include the radio and servos. These are usually selected by the builder based on his own preferences and budget. In the case of the A600, due to the tight dimensions of the hull, there is little to chose from.


The rudder servo is the most ordinary. Any standard size servo can be used. You'll be making the mounting frame yourself, so you can customize it to match your servo. These typically cost from $10-$20, see Tower Hobbies. Any hobby shop with RC gear will also carry standard servos.

Crewman winch

The A600 uses a standard sailboat winch in a novel way. Instead of hauling in sails it is used to pull the ballast/crewman from side to side on the deck. All the necessary bits (line, fittings, etc.) for this assembly except the winch itself are included. While more expensive than an ordinary servo, the Hitec winch model they selected for the prototype A600 is commonly available here in the US.

The crewman's winch recommendation is a Hitec HS-785HB, which sells for $40 from Tower Hobbies. You may even find it at a well-stocked hobby shop.

Sail winch

The sail winch is constructed from a special low profile, hi-torque servo: these are called aileron servos because their low-profile lets them be mounted inside the wings of larger model airplanes. I looked high and low and found three possible candidates on this side of the Atlantic: Unfortunately, none of these has the torque of the Supertec model they used in the prototype A600. These three all have from 62-77 oz.-in. of torque. The Supertec S136L used in the protoype has a whopping 111 oz-in. of torque (if my metric conversion is correct). I found the Supertec for £18 at Galaxy Models in the UK, so I ordered one from there. The total cost was £18, less their VAT tax, plus £6 shipping, for a total of £21.31. My order from Galaxy arrived very promptly and I felt like it was a good deal.

I don't know if you can get away with the lower torque American servos or not. It wouldn't hurt to try if you have one laying around. By the way, steer clear of "retract servos" which are not proportional. They're made to be Up or Down, not in between.

You can see more about the application of these servos on my page about the servo tray.

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