Socket for splined driveshaft on an electric motor

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(I spoke to Mitchell) I have an electric motor with a 6.3mm driveshaft with 7 splines. I am looking for a socket to slide over the driveshaft without damaging the splines, to drive a propeller shaft in a model boat. Preferably the socket should have a square drive hole and driver so I can fashion a connection to the propeller shaft (which is 6.4mm/1/4 inch OD). I will attempt to attach some photos.
Thankyou

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Geoff Prescott

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Hi Geoff,

That’s an interesting problem, as most of the couplers that I would usually recommend here would likely have the potential to damage the splines, is there any way you would be able to machine a piece of rod to have an insert that matches your spline to fit over it? Then it would be as simple as fitting the connection and adding a coupler such as the one linked below (also, depending on the material the shaft with splines is made of, you may be able to get away with providing sufficient pressure to fit, but not damage them)

Unfortunately, these are out of stock right now and are unavailable for purchase, but something similar would likely be the best way to go.

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OK - thanks Bryce
Geoff

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Geoff
Is there a thread in the end of the motor shaft?
I think a coupling with a little bit of flexibility would be the go here. It may be very hard to get the motor and prop shaft perfectly aligned.
Is there much of a load on the coupling?. If you can’t get anything suitable you may get away with (in the short term anyway) some thick walled heat shrink tubing. Most heat shrink thickens up when shrunk anyway as the material has to go somewhere. The really thin stuff would be no good. Even the tubing with glue may be worth a try.
Cheers Bob

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Thanks Robert - I will work on it …
Geoff

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No worries Geoff,

Make sure to let us know how you go!

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Hi - problem solved. I filled a 1/2 inch socket with polyester resin and made a mould of the motor driveshaft . I coated the driveshaft in oil to prevent the resin sticking to it. The 1/2 inch socket has a 1/4 square driver hole at the back, and I used a suitable driver shaft to connect with the propshaft directly. It took a bit of fiddling to set it up straight and true but so far it is working well. I might add the model boat is 1.52 m long and weighs over 17kg, and the electric motor is a high torque 18 volt unit from an impact drill.
thanks
Geoff

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Ouch!!! My idea of heat shrink probably would not have lasted 5 min.
Great to hear problem solved. Pretty good solution. It is a fiddle getting this sort of thing aligned properly but if you don’t things will start falling apart after a while.
Cheers and well done. Bob

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Thanks for the comments Robert
Geoff

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Thank you for letting us know the final outcome. Sadly I don’t think that many do.
Cheers Bob