Shaft size question

[Greg Ruggles]

Is there a rule of thumb for what size shaft to use for a specific range of motors? At what size do you use a .250 shaft? Is it anything size above a .60 engine you would use a .250" shaft? Also, when would you use a square drive?

 

[RaceMechaniX]

Generally as follows:

.12 .125-.150" cable or .062" wire
.21 .150-.187 cable or .098" wire
45 .187 cable or .098" wire
60/80/90/101 .25 cable or .125" wire

The decision to run a collet or square drive depends a lot on the setup and boat. Lots of arguments for both.

 

[Greg Ruggles]

Generally as follows:

.12 .125-.150" cable or .062" wire
.21 .150-.187 cable or .098" wire
45 .187 cable or .098" wire
60/80/90/101 .25 cable or .125" wire

The decision to run a collet or square drive depends a lot on the setup and boat. Lots of arguments for both.

The boat is a 46" twin craft mono and is going to have a picco 90 with a surface drive. So use the .250 cable? With or without the square drive? Thanks for your reply.

 

[the german]

Greg
You'll find thousands of answers. In my opinion is the square drive the way to go. I would use a .250 cable with a square on one end and a soldering ferrule on the other end . You can take a look at the website of Dave Rippe / Hyperformance Products to see what you'll need.
http://hyperprod.bizhosting.com/index.html

Alex

 

[Greg Ruggles]

Greg
You'll find thousands of answers. In my opinion is the square drive the way to go. I would use a .250 cable with a square on one end and a soldering ferrule on the other end . You can take a look at the website of Dave Rippe / Hyperformance Products to see what you'll need.
http://hyperprod.bizhosting.com/index.html

Alex

Thanks for the input Alex. I'm a newbie and just got my 2nd boat, I have a lot to learn.
Thanks again.

 

[RaceMechaniX]

Greg,

1/4" flex cable is the way to go. Square drive is preferred for engine longevity as it places the thrust forces on the strut instead of the engine bearings. Looking at the plain plastic washer on the strut versus the ball bearing in the motor you would assume the ball bearing is superior, but I will attest to the fact that engine bearings will last significantly longer if using a square drive and just replacing the thrust washer once a season.

Setting up a square drive usually takes some skilled soldering/brazing of a ferrule to the flex shaft. This is not a beginner task! There are ways to use double squared cables or ferrules with squares broached but finding the right combination of parts can be frustrating. As a newbie, let me just recommend going with a traditional pinch collet and welded cable. Save the square drive for a later build.