Motor alignment with flex shaft.

[martin]

Is it best to have the motor set slightly above the flex shaft so that the flex bends up slightly into the coupling to stop the flex from whipping between the coupling & the stuffing tube. Also is it best to have a more gentle curve in the stuffing tube over the entire length or do you need more curve in the middle area of the tube. Thanks Martin.

[Fluid]

There should be less than a 1/2" gap between the coupler and the stuffing tube. The alignment should be perfect. In general, gentle curves are best but there are exceptions. Need more indfo to answer this...boat, cable size, angles, etc.


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[martin]

The boat is a 15" micro mono with a .090 flex which is 5.25" long + 2" stub shaft, The stuffing tube had most of its curve in the middle 2"of the tube & straight either side of this bend . I going up to a .130" flex with a bigger stuffing tube fitted to take the larger diameter flex, What i found was happening is im running around 42000rpm unloaded on a metal x435 to which i was probably just getting away with on the .090" flex. Ive gone to a x632 which has slightly more pitch & seems to be winding the flex at the motor end. (when i take the flex out theirs a spiral in the motor end of the flex). I know i was pushing this size flex. Ive seem on some boats that the motor aligns with the flex at the point of the flex entering the coupling but the motor is sitting at a more accute angle than the flex & when the flex is pushed into the coupling you get a definite curve up of the flex to the motor line. Is this done to stabalize the flex from whipping or any other phenomanon happening to this end of the flex. Thanks Martin.

[Fluid]

Ive seem on some boats that the motor aligns with the flex at the point of the flex entering the coupling but the motor is sitting at a more accute angle than the flex & when the flex is pushed into the coupling you get a definite curve up of the flex to the motor line.

Lots of follks do really silly things to their boats. That is a wonderful way to destroy your flex cable. Their theory is full of holes, as their hull bottoms may be when their cables fail.

Flex cables have been in use for many decades, there is no "new way" to make them work better. Use the stuffing tube to "stabilize" the cable, not additional strain on the cable.


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[martin]

Thanks Fluid, Any idea how much is an ideal difference between the flex diameter & tube id, Flex is .090" liner is .130". Does .040"seem to much clearance to stabalize the flex at 42000rpm unloaded. Thanks Martin.

[greenblast]

keep the motor and flex shaft lined up perfect. but most of all make sure there is no flex in the motor mount .if the motor pushes forward it causes the drive dog to bind on the strut. and worst case it twists up your flex. blowing your esc . ask me how i know lol.