Flex shaft Setup??

[Terry Heddin]

What is the best way to setup a 1/4 flex shaft in a hydroplane? I have planned the setup like first pic, but others have said that is bad, and suggested similar to second pic.
One bend, or "S" bend, and location between strut and engine?
Thanks.

 

[Martin Law]

Terry,

IMO, a straight shot from the C/L of the collet thru a short sleeve that goes thru the bottom of the hull. This is needed for strut adjustments and also makes it so the stuffing box tube is replaceable.
Then, a smooth wide sweeping radius bend starting from the sleeve bottom exit to make the tube follow parallel to the bottom of the hull no more than what your strut depth is going to be. A single wide smooth bend is preferred. Pretty simple...

Marty

 

[Daniel's Racing]

I just posted almost the same reply over on the dock where he asked the same question.

>>

Neither is great. #1 is all the bend in one spot which is no good. #2 you have way more bending going on than necessary as you do not want bends from bottom to engine for sure.

Just angle engine down headed a bit below the strut then after you exit the bottom put one long gradual bend to the strut.

You have to be able to sleeve from bottom to the engine in a straight shot so you can run a sleeve through there as tube can't be locked in place and you want it to be able to be pulled out of your sleeve for replacement.

That is a lot of bottom slope for a hydro under and aft of the engine. It should be almost flat or your going to have to much lift.

Pics of the hull ?

 

[Terry Heddin]

Terry,

IMO, a straight shot from the C/L of the collet thru a short sleeve that goes thru the bottom of the hull. This is needed for strut adjustments and also makes it so the stuffing box tube is replaceable.
Then, a smooth wide sweeping radius bend starting from the sleeve bottom exit to make the tube follow parallel to the bottom of the hull no more than what your strut depth is going to be. A single wide smooth bend is preferred. Pretty simple...

Marty

Does look like it will be a better setup?

 

[Daniel's Racing]

Yes sir. That is more like it.

 

[Terry Heddin]

Yes sir. That is more like it.

OK, thanks. The tube in my first pic is bent to the pattern for my SLR Missile, and just reversed. I have a new tube on the way.

 

[Mark Anderson]

What Terry said.
The tube in your example appears to have been heated. Don't heat it. It will make the gradual bend no problem without annealing it.