Stephen. There is no rule of thumb for using single or twin shafts. It boils down to personal preference. Obviously a single shaft setup is slightly cheaper and easier, but it is nice to have the right amount of props for the type of vessel being made (another personal view).

I would say a low power mfa 540/1 type brushed motor would provide sufficient go for a single shaft, and in the event that you found this wasn't fast enough then there are other 540 or 600 motor options that would fit straight in for more power.

For twin shafts, a pair of 385 type brushed motors would be adequate for your vessel, or even 380`s or 400`s for more grunt. Cheap option, mounts all the same so if you were unhappy with the 385`s, a swap would be very easy.

I always fit as large a rudder as is consistent with not looking too odd to provide maximum manoeuvrability. A large rudder can always be cut down….enlarging a small one is more difficult. I like to use nylon clamp style tillers, as these can be done up just tight enough to hold secure, but are easily tweaked for balance etc by hand at the pondside. I replace the standard nut/bolt with a longer bolt and a small nylock locking nut, to maintain clamping pressure over a period of time.

A single rudder between twin shafts is never the best option, but if the rudder can be made a bit longer that it might otherwise be, so that at full deflection some of it is in the wash of (whatever side) a prop, this can help immensely.

Use slimline shafts perhaps for a twin setup, fatter standard one for a single.

Ashley

.

Me too, like Ashley I've been making my own rudders since I was a youngster. It also allows you to use a shape that will suit the twin prop one rudder set up.

I forgot to ask what size props you were expecting to use, it might make a difference to what I posted earlier. Ashleys post reminded me of something, I presume you know about having the props turning in opposite directions, it helps keep the boat going straight, just buy / make a left and right hand prop.

Chas

Ahhh, another can of worms. I've read posts in the past saying "do it this way, or do it that way" Full size practice is xxxxxx. Like many ordinary time served modellers, I've tried all the permutations. Guess what, there was no difference in the performance in any of the models I've made.

I'm quite sure there are modelers out there who have noticed something, but after 55 years and too many boats to count I never worry about it. I'm far more concerned with deteriorating eyesight, co-ordination, and glueing myself to the blasted model……..Again.

Chas.

Twin prop rotation is a subject which has been done to death on at least one other Forum. The general concensus is that there is no correct way – outward rotation suits some types of model while inward suits others. I guess the solution is to try both and see which works best for your model.

Dave M

Hi Stephen, a few things there. Firstly the props, start with 35 mm 3 blade, they're usually the best match for 385 motors. You can buy a few different size plastic ones to experiment with if you want to, they're cheap and effective.

Re the speed controller, why not start out with one, if the turning circle isn't what you want then you can spend more one a twin ESC and mixer.

Lastly the rudder, you don't say what you difficulty is, but hear is my and many other peoples way of doing them.

Find some rod and tube to make the assembly, slot one end of the rod about 5 mm to take a piece of brass sheet.

The brass sheet can be any old off cut, say about 1 x 2 cm, solder it into the slot.

Next cut 2 pieces of plasticard in the shape of the finished rudder, cut a tiny slot where the post will be.

Put the plastic in very hot water to soften them, then clamp them around the metal bits until they harden.

When dry use epoxy to join them and clamp again. You can do some final shaping with sandpaper when its all set.

It takes me about an hour to make a rudder, costs peanuts and is easy to change the design if I want to.

Chas

I was forgetting about the finer pitch on 40 mm plastic props, so they're OK too. Brass ones tend to be coarser so 35 mm would still be my choice.

I like a scale looking rudder on a scale model, that's why I skin them, it only takes a few mins, on other models I don't bother either.

Really there aren't many wrongs or rights, it's a fun hobby, we just do what works for us.

Chas