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[tizdaz]

How does the motor shaft attatch to prop shaft? Ive read about couplings, does the shaft on a motor have a flat edge to prevent the shaft/coupling from spinning loose etc?

[tizdaz]

Im guessing its this that i need:
http://www.mobilemarinemodels.com/large-safety-coupling-974-p.asp
But how does this attatch to motor shaft?

[david48]

With a grub screw  the small end pushes in to the silicon tube

[Martin (Admin)]

 
One of the first pages on Mayhem, from many moons ago... 

http://www.modelboatmayhem.co.uk/My_models/01%20piranha.htm

[tizdaz]

Ah ok cool, i see the flat spot on prop shaft, is there also meant to be a flat spot on the motor shft for the grub screw ?


Cheers

[Stavros]

You will need to file a flat spot on both the motor and shaft




Dave

[malcolmfrary]

In practice, there should always be a flat to associate with a grub screw, although grubscrews do come with a variety of ends, some capable of forming a dent in whatever they are fixing to.
Some prop shafts have a threaded inboard end - the intention there is to use a coupler insert that is similarly threaded.

[NFMike]

How does the motor shaft attatch to prop shaft? Ive read about couplings, does the shaft on a motor have a flat edge to prevent the shaft/coupling from spinning loose etc?

As you'll have gathered from the above there are a multitude of systems to get from motor to shaft. Pragmatically, just get the motor you want/have and shaft you want/have, see what ends they have and get a coupling (of the type you want) that has fixings to suit. As said, for a grub screw you may decide to file a flat if there isn't one already.
You don't have to have the same fixing at both ends of the coupler - a thread to the shaft and grub screw to the motor is very common.

[imsinking]

Motor shafts are normally plain Dia , some prop' shafts can be plain too, as said grub screws are required , don't super glue or loctite the adaptor's, on you'll have to destroy them to get them off .
Bill

[tizdaz]

oki doke, thanks again for info, will wait until i pick them up & see whats what, if the motor shaft is all round, then i will probably file a flat spot for the grub screw to prevent the motor shaft from spinning loose :)

[NFMike]

... , don't super glue or loctite the adaptor's, on you'll have to destroy them to get them off .

But do consider loctiting any grub screws. If they work a fraction loose, they unscrew very quickly to the 'no drive' position.

[tizdaz]

Aye will do, thanks again guys


Will let you know how i get on when i start the build thread, be a few weeks yet as the hull is being made, its only been 2 weeks but feels like ive been waiting 6months already! lol :-(