Flex shaft problems

[Jim Caldwell]

It only takes 1/8" curve or S bend to cure the whip.

 

[Charles Perdue]

David, in testing a lot of driveline setups. A gradual arc of 6 to 8 degrees is the best that I have found. Raise and tilt the engine to get this. It will not make that much difference to the roll center.

Charles

 

[dr gary turner]

Years ago Ed Lackey was trying to set a straight away record at Huntsvile. He would make a pass and the boat stopped suddenly and when brought in the shaft was bent at a right angle. He was running a Mr G hardened steel solid shaft in a tube of ball bearings. This happened on every pass. Finally "THE LIGHT CAME ON IN THE ATTIC" Every rotating item-shaft will creat a SINE WAVE. The shaft was TOO contained by the series of ball bearings and the energy of the sine wave was being disapated at the only area that was not contained which was where the shat was not contained by the ball bearings. IE it was like a BULLWHIP with the snap at the end the solid hardened steel shaft bent at a right angle

Your flex shaft is in a sine wave and the energy is being transmitted in the area that is not contained . A bend some where in the the stuffing tube breaks up the sine wave

 

[dwilfong]

Thanks for all the input.

Never even thought a strait shaft would cause a problem.

If some one would have told me it will not work I would have said ya OK and done it any way.

Doing it and seeing the results is the best learning tool.

Live and learn!

 

[shoboat]

David,

You gotta a long life ahead as do I with the live and learn concept.

I only wish we could believe others before we do it two or three times

to learn for ourselves. Oh well keep on testing those propellers. How

did the last one work for you? Charles is giving you the right information

with the 6 to 8 degrees.

Thanks,

Mark

 

[dwilfong]

David,

You gotta a long life ahead as do I with the live and learn concept.

I only wish we could believe others before we do it two or three times

to learn for ourselves. Oh well keep on testing those propellers. How

did the last one work for you?

Thanks,

Mark

Worked good .

But it still likes a MW3 the best.

Don't know what it is about that prop. But my big monos love it.

 

[shoboat]

David,

I have plenty of MW-3's in stock.

Do you have room under your Christmas tree still?

You know the Winternats are coming fast?

Thanks,

"Santa" From The North Pole

 

[dwilfong]

Ya got plenty of room.

just Put some in the middle.

Going to try that other one on my Hydro.

 

[Michael Costanzo]

Yep otherwise the shaft become a " jumprope "

dave, i think that is one of the reasons that the JAE has the "s" bend in it,to take out the whipping effect.good luck.

 

[dwilfong]

Yep otherwise the shaft become a " jumprope "

dave, i think that is one of the reasons that the JAE has the "s" bend in it,to take out the whipping effect.good luck.

Ya know when I first saw the JAE set up I thought as many it would add drag or eat a hole in the tube.

How wrong are perceptions of thing change when you see why first hand.

You run the Nuclear Banana lately?

 

[Tom Foley]

Actually

I think it was Don Pinckert That mentioned this but I could be wrong .Think of the shaft like the chassis of an Outlaw sprint car . Car does not handle until it is all loaded up and twisted under power just blowing around the corner .The shaft actually has less contact in the "S" bend setup .