I am thinking about a moveable turn fin for a rigger, one that can be lowered with the third channel when rudder is applied so that the boat will turn? I am thinking I can use the mixing function to make it operate off the third channel.

Has anyone tried this or have any ideas on it??

This is for straight line speed only.....

mike sr

I forgot to turn on the email replies section........

mike sr

Mike Sr
I don't think that I would try to mix it with rudder as a small correction would begin to lower the fin. I believe this could put things into a oscillation as rudder and fin were added at the same time. If the fin is straight as the type used on a mono, which I would think would be the case on a SAW boat it should work. If it is curved as on a oval course boat I can see some real spectacular gyrations as it went into the water. I woukd be inclined to operate it as a separate control function as it could be used in several ways. In my case as I use a multi channel stick radio. I would use the ale. for rudder, ele. for fin and throttle as normal. Just fly it like a tail heavy airplane. Sounds Interesting keep us posted Ed

I know on the third channel it can be set to end to end on the servo, I think a small straight fin, just enough to turn it around in our 40 acre lake, it may be interesting to say the least, years ago the fins were straight and the boats didnt turn well but they did turn, without a fin it wont turn at all on my particular rigger!
I love the experimenting, thats most of the fun in this hobby for me...
I am thinking about a push pull cable off the third servo and leave the servo in the radio box, I was never a fan of open servos.
I need to get the mechanics worked out first I guess, the short fin I have tried was good for about 1 to 1.5 mph and reduced the right pull considerably.

mike sr

Since this is just to turn your boat around (not at speed) I would probably mount the straight fin on outside of the tub, starboard side anywhere there is room in the approx area it needs to be. A simple bushing in the tub, with fin secured to one end and on the other end of the shaft, inside the tub, a simple control arm. Would allow for up down (90 deg) movement of the fin with a servo from the box...straight line linkage. Just my 2 cents worth

Good idea Marc! I didnt think of putting it on the tub, that would make it much easier.

mike sr

How about mounting the fin on a bushing on a sponson support tube,say like a brass wheel collar. There is going to be a helluva straiin on a bushing/support with the length equal to the thickness of the hull.

If it's just for turning the boat around at low speeds, I don't see it being and issue...assuming the tub sides are 1/4" ply. Otherwise, just reinforce to suit.