Macedonian, a British Frigate of 38 guns,c.1812, in 1:36 scale for RC sailing

[Roger Pellett]

Lots of Classics there.

 

[JerryTodd]

Initially, I was going to put the same brace-winch set-up in Macedonian that I have in Constellation, but trying to control the tacks of the courses with flat winches wasn't going to work. Keeping the braces on their drums without any gear-shifting (like the derailer on a 10-speed bycycle).
I stuck Mac's pallet with her brace winches in a vice to do something to it, when it struck me to plug a winch servo in and play with the idea of turning the winches on their sides. It seemed to work well, even with significant slack in the lines. I 3D modeled the idea, to figure out how I'd mount the servos.

Recently, while doing some research for a web-page on RC sail controls, I came across a video on Youtube where Georg Reinbold explains the brace winches on his bark Nernberg. The function was as I had found with my experiment above, but it was the way it was built that really appealed to me.

So I drew up a rig specifically to fit Macedonian. I mounted the winch drums for each mast on a single frame because unlike Nernberg, I'm not actively controlling every yard; like Constellation, I'm only controlling the tops'l yard on each mast, and the tacks of the fore and main course sails. The tacks because that what matters when sailing a square-rigger on the wind. The frame holding the drums will sit on a pair of beams fixed inside the hull. The servo mounts will be on a small deck below that, probably resting on another pair of beams. Another 3D model was made to check sizes and clearances.

I looked closely at the construction of Georg's winch drums to see how the braces are attached (and a failed first attempt show in another of his videos). It seems there's a hole in the axle at each drum, and the brace is threaded through and knotted.
I'm concerned the knot could interfere with or snag the brace as the drum turns, so I'm thinking of using a larger diameter brass tube instead of a rod, for the axles. The brace would thread through the hole in the drum and into the tube, and it's knot would be inside the tube.
Hopefully this will allow me to rig the tacks on the courses, and if it all comes together, I'll probably retrofit it to Constellation.

 

[JJ Lad]

It would seem that one would benefit of more effective tacking by pulling in the jibs, and letting out the spanker. Although less sheet area, the forces at work benefit from greater leverage around the point of rotation.

 

[JerryTodd]

In my set-up, the heads'l are on two-arms driven by a single arm on a servo. Since the heads'ls all overlap each-other, and have to cross-over stays when tacking, my set-up casts off the sheets, but can also pull the windward sheet to box-the-head. Additionally, the squares on the fore-mast are driven on a separate winch from the main and mizzen, so it can be used to box-the-head as well - just as it works on the real thing.
drawing of the two brace winches and "semophore-heads'l-sheeter"; photo of the set-up through the main hatch; and Constellation coming-about with the heads'ls and foremast sails aback.


Tacking, or coming-about, isn't what I'm trying to address; I'm concerned with setting the courses when sailing close-hauled by controlling the clews as they are on the real ships by using the tacks. Constellation's winches are flat, and move to maintain tension of the braces. Because of that, they can run a fixed-loop circuit, or maintain constant tension on a simple tack/sheet loop with the danger of the line falling off it's place on the winch-drum - derailing.
Turning the winch-drums vertical reduces the problem because the over-sized flanges keep any slack on the correct drum.
Some may not get my explanation of it until you see it in action

I played with the 3D model to simplify it by putting the servo mounts on the frame with the drums, the whole unit sits on a pair of beams fixed inside the hull. I was real pleased with this arrangement until I saw a problem; there's no way to install or remove a servo. I'm a big proponent of access for repair and maintenance, and I don't want to alter or damage the servos (voiding any warranties) so catching issues like this are why I modeled it in 3D first.


The fix was actually fairly simple; the drums and fairleads are on their own frame, with the servos on their own separate frame that's removable from the beams and will allow the servos to be mounted or unmounted as required - see exploded view.

 

[JJ Lad]

I understand... however my original comment remains germane. You've created a complex engineering solution that will demand increased maintenance and presents multiple failure points.

Course setting can be tuned with jib and spanker placement. Of course your radio will need sufficient proportional channels to support these functions.

Current IOM hull designs recognize these risks and locate their winches with simplicity and maintenance access as top priority.

And where our scale-models are typically not raced, I would rather not have to spend my time dock side untangling my running-rigging.