replacment for couplings

I hate couplings for models they are noisy and waist power I try to get rid of them as much as possible, I normally on my boats try to use a belt drive but recently saw another option to do with brushless motors, on my latest fire boat I was going to go belt drive but as the KVs have come down so much it is better to go direct drive , this is what I am doing I have made up two sets (four in all) for two twin screw boats, you fit a brass flange on the end of the prop shaft and then remove the shaft out of the brushless out runner and replace it with a long prop shaft, you have to lighn them up correctly and use extra ball races, I have also fitted a cooling plate that will help with the welling up of heat you get when you stop running, the motors used are quite powerful so we will soon see if it works with big motors, the example I saw had been in use for some time but in a slower scale boat , we have run one example in a sink and it seems to work fine shifts a lot of water.

Hi Peter

As always your work looks great and the thought and planning you must have done really shows up in it's engineered finish. I wish I had 5% of your skill mate. When do you think the boat will be ready for a run?

Dave

A question from someone who is ignorant of these things.......No make that two! What is wrong with ordinary couplings? and what is the real benefit of all your hard work. I appreciate the engineering skills involved, but really do wonder whether it is all worth the effort? I have never found my couplings to be noisy and as for wasting power, does that only become important if you are trying to achieve top power as in racing boats?

Oops sorry that was four questions...

The brushless motors(2) in question are going in a old 46" aerokits fire boat ,they are not a light boat, also the newer brushless motors with lower KVs deliver power instantly if you want so couplings tend to break, these motors are slower reviving and you can fit a scale sized prop and get the performance to make the boat look good on the water, also get longer run times, these motor each probably put out double what a Taycol super marine put out, one thing about using brushless motors is that they are much more efficient by about a third . another reason is that there is no extra mounts req just support the shaft and that's it, you don't need to cool the motors, but they have no brushes they are on good ball races so the only thing that can wear in a way are the magnets and what kills them is heat so if you can keep everything cool you will get longer life out of the motors , as I said in the last post they get warm after you stop so if you bring them in slow it stops it a bit.





Peter