Cable Steering Setup

Hello there!

My students and I are building a small 10' hydroplane. We are currently working on the cable steering. We have it all installed but there is one thing that is not clear to us. Basicaly it all comes down to deciding on the length of the steering bar that is attached to the outboard motor.

Here is the question: How often should you need to turn the steering wheel to get full deflection of the motor from the middle to one side? Or: What is a common length of steering bars (from left pulley to right pulley)?

Currently, we need to turn the wheel almost 6 times to go from all the way left to all the way right. Is that reasonable?

Can anyone help?

Thank you.

Karsten Weiss
Design & Technology Instructor

 

Do not run the boat like that. Hydros vary from about 1 : 1 to about 2 : 1. Ability is the determining factor. Quick response in a group of boats in a turn is CRITICAL.

 

Follow up

Thank you for responding so quickly.

We are not racing so I am not terribly concerned about racing in a pack and reaction time, but I want to have a boat that is set-up the way it is customary and safe. I hope I understand this right: you suggest that our steering is not direct enough and to set it up that one or two turns of the steering wheel turn the motor from all the way left to all the way right.

We are beginners and I like it to be not too direct (students might try too radical maneuvers), but I like them to have fun in the turns.

Would you find it reasonable with setting it up so that turning the wheel one full turn (while the boat is going straight) results in full deflection of the motor to one side? Two full turns from all the way left to all the way right?

Thanks.

Karsten

 

Ok . Go to 4 turns lock to lock. If you get clever on the pulley from a multi speed drill press, you can change the ratios over a 2 to 1 range easily.

 

It is customary in a cable steering system to have both cables under spring tension. If any part on one side or the other fails, (cable breaks, spring breaks, cable clamp lets loose, spring attachment to hull lets loose, cable comes off the drum) the spring tension on the other side will yank the motor sideways. That could be exciting but not safe, that's why cable steering is not seen on many boats anymore. The older A+B hydros had a dead-man throttle, you knelt in the boat and steered with one hand and squeezed the throttle with the other, if you fell out, the motor quit. You should put a kill switch in the boat, we use to make them for motorcycles by hooking up a set of points from an old car distributer so they would ground out the ignition when closed. A piece of plastic from a milk carton, with a string attached and tied to the wrist, kept the points open. When thrown from the bike, the plastic went with the person, the points closed, the motor quit. Seeing as how the steering was one handed, I imagine it was pretty quick but keep in mind that you probably won't be turning the motor all the way over in a turn at speed. What plans are you using for the boat? How did you work out the details like who pays for the materials, who gets to keep the boat? Sam

 

I do not see how much safer the modern rack and pinion cable is when it binds in a turn. I have never used springs. Why? Tight lines are fine if maintained. When a Teleflex locks up, you are toast without tools. Pulley and cable is driveable at ANY time.----------------Buy a ignition safety lanard that clips to your belt.

 

I have found that all Johnson & Evinrude OB's have a very usefull hole in the front carrying handle for steering setups. A shoulder bolt, washers and a self locking nut are all, that are needed.

 

Thank you folks, I heard what I needed to know for now. I am sure there will be more questions at some point.

We will make sure to attach the hardware so that it does not come loose and wathc the spring tension. We are using a dead man throttle, but no kill switch.

The boat is a small outboard runabout from Clark Craft. It will be painted in school colors (gold and green) and will be kept at school (since my high school budget paid for all of it) until we sell it to buy supplies and such for the third boat. We have started a small three-point hydro this fall (our second boat).

Thanks for the good advice.

Karsten