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[Andyn]

At the start of this year I acquired an AC Pro 40 hull, that had been started in so much as inserting the engine mounts, fuel tank and buoyancy foam.


This hull is designed for a 40 engine to race in the popular Sport 40 class in the US. Unfortunately I don't have a spare 40 lying about (ok I actually have two), so a new A90 will have to do. I'm not expecting it to be drivable (or barely controllable), but it'll be a lot of fun either way.


Part of the issue getting an engine double the capacity the hull is intended for is clearance, or lack thereof. The existing mounts fit the engine after a trip to the milling machine, but the engine ground out in the bottom of the hull. The mounts were redrilled to allow the bobbins to sit further up, so it's now where I want it. The next issue is props - I've mounted the strut in the place it's called for in the manual, but that is to fit a 47mm prop under the transom. Due to how much area I have on the prop sizes I'll be using, I'm limited to props with the blade behind the dog, which puts out the Octura 4 series props, which are most of what I own. I have a choice of three so far that will fit, so hopefully one of them works


As it currently stands,  all that is left is to make and fit the push rods, make a turnfin bracket, attach the pipe mount, mount the fuel tank and decide how I'm going to retain the canopy. Then it's just run in the engine and find a spare pair of undies 

[DJW]

Morning Andy..!


Love it. Can't wait for the video of first run...  (Better video that first run just in case you lose it in orbit...)


David.

[derekwarner]

Andyn......that Savox SV0236MG servo on 7.2v, has a massive 555oz/inch...or 30 something lb/inch.....or about 15kg/25mm 


Assuming for the torque effect load on the rudder?...or is it a higher voltage & superior control?


With a rudder setup like or for this application, what is the weakest link?...are there mechanical stops built in to the linkages or hull proper?


Derek 

[Martin [Admin]]

... That rudder servo looks bigger than a couple of whole boats I've built!   

[SteamboatPhil]

Blimey Andy, that's one hell of a set up, you sure it shouldn't have wings 

[Andyn]

Andyn......that Savox SV0236MG servo on 7.2v, has a massive 555oz/inch...or 30 something lb/inch.....or about 15kg/25mm 


Assuming for the torque effect load on the rudder?...or is it a higher voltage & superior control?


With a rudder setup like or for this application, what is the weakest link?...are there mechanical stops built in to the linkages or hull proper?


Derek

I went with the 236 because I had it in a drawer and no use for it    the rudder has a built in weak point having an M3 brass screw below an M4 stainless screw on the mount, so if it finds something to collide with in the water it shears the brass bolt and kicks the rudder up. Everything else is solid, pushrod is 3mm steel with hefty ball joints.


It'll definitely be recorded on it's first run, though I've got to run in the engine before I can push it