flexible propeller shafts

i am just starting on a model boat with twin Korts nozzles,which i purchused from MMJ and very nice mouldings indeed,as the korts have to be mounted in horizonal position and motors are quite high up in hull i think it would be best for a pair of flexable shafts,but where can i obtain some?

the model is a American pusher tug of 750mm size

Has anyone any thoughts on this matter

regards Jeff

Just a tought the Korts were purchused from MMJ, not the tug which i am scratch building

Jeff

Jeffrey. Flexishafts are really meant for racing boats which have motors forward, to keep the prop line flat.

They require a lot of maintenance, as the wire wound drive is not rustproof and ideally needs stripping, drying and re-greasing after every run. Usually this means loosening the solid coupling grub screw or collet, and withdrawing the shaft rearward.

Cant say that I have heard of flexis being used in a tug, but I may be horribly WRONG!

I would think that a small downwards angle should not be that detrimental to the Kort? Also, why are the motors so high? Normally something you would install low down.

Ashley.

Hi Jeffrey, yes the korts need to be horizontal, but there is no practical reason why the props and shafts cant be angled, it's what I and hundreds of others do. Normally we just adjust the motor and shaft layout in the hull to give as flat an angle as is practical, remembering to position the motor and coupling where they can be easily accessed for maintenance.

Like Ashley, I've never heard of flexies being used in a sedate model, all that messing about in a delicate scale model wouldn't be for me.

Charles

Tugs do need reverse, flex shafts tend to unwind themselves in reverse, so they don't get used on tugs.

Agreed. Never use flexible shafts if you need reverse which you most certainly do with a tug.

I am not familiar with MMJ, and thus clearly not your model, but with a tug hull it is normally possible to mount the motors quite low. Yours must be the exception.

Edited By Chris E on 01/01/2021 10:03:42

Hi again, as you can see, people on here would all like to help. I suggest you post some pictures, this might make a big difference to the advice you get. If you haven't posted pictures before, go to all topics, and look at the item on posting pictures.

Charles.

many thanks for your replies,i did not relise that with the kort mounted horizonal the prop inside could be at an angle very slightly,as this was pointed out in the post by Charles Oates ,so this has solved the problem.

all have a happy and good New Year

Jeff

live in New Malden

Perhaps this will help.