stupid question about cable pully steering

[TTriton]

I've been told that using this steering with a hydrolic jack plate is tricky since the engine changes position but how about using trim? Would I be able to trim the engine all the way down to jump it up then trim it up to run with out the cable being overly tight in one position then slightly loose in others? I've never driven a boat or been around one with this steering system so If I have been I'm sure I would know.

[LJL]

The trim also changes the cable's lenght. I've seen many racers just tightening the cable as tight as they can get it. The cable ofcourse loosens, and they just tighten it some more. Maybe the best system I've seen has gas springs. They load the cable all the time, and there will be no slack. If it's setup right, you'll have a very good steering. No play or neither will it hit back hard, when the motor enters the water again, and you'll get excellent feedback. Cable steering very propably the best steering, if you aren't running offshore. My $.02

LJL

[Raceman]

Lee, I've run cable/pulley steering on my boats since my first 15 Allison in mid 70's. (no jackplates then) I don't think it's real practical with a hydraulic jack, but I guess it's possible. Bare in mind that improperly designed steering arms will create the same problems. The tips of the arms need to be roughly at the intersection point of the two planes created by the swivel and tilt pins or the cables will tighten or loosen when the engine is tilted or trimmed. As far as cable adjustment, they'd have to be adjusted fairly tight when the system is the most stressed (generally top of jackplate travel) and just live with the slack as it is lowered. I wouldn't adjust the engine to "overly tight" in any position. If you always run the engine at roughly the same heights at WOT and just use the lower heights for gettin on top, I'd adjust it properly for max height.

[H2Onut]

Heck, usually on cable systems there are tension spring(s) located in transom well, You may have to with a larger spring steup, but in theory it should work, key word theory. Maybe use some blow boat (sailboat) technology, use a track in which pulley can travel up and down. Maybe ??


Good luck amd keep us posted

[Techno]

My take on this is you wouldn't want any kind of vertical change if you were using cable steering. Not because of the engineering involved but it should be in the best location for performance. Isn't that the reason for the cable steering? It's not to go skiing with is it?
Kind of like manual steering and power brakes or such.

I'm not totaly sure of the system but I would think that if the exit point leading back to the OB were also jacked then this would eliminate this problem. Or if the exit point is the set of pulleys normaly under the dash, moved outboard of the cockpit. It would form a triangle about 15' long with a base of only a few inches, the jack hieght. Might make alot of cable slap though. Whos engine was shut of from this?

[patchesII]

raceman let me know what you think but it seems as though a hyd. jack would work with the cables depending on how upright the transom is on lee's boat. it doesn't seem as though the straight up and down travel of the jack would have much effect on the cables tension. hey lee we run cable steering on our 16 ft speedcraft and i think generally boats that run this type of steering operate in a narrow range of trim and this is how cable tension is kept consistent. when we set ours up it took some trial and error but we got it right, and we don't use any tensioners.

[DRAGIN FLY]

my RS/CCC motor has up down and trim with cable steering I have never seen any other steering system on these motors not alot of trim or lift but still some Good Luck !

[TTriton]

Well.. Two things.. I have decided to go with a manual jack plate for weight resons and money reasons. And I've also decided to go with dual rotary cable steering with push/ pull cables. I know the pully style would be a better choice for racing but since I have never set one of these up and this will just be a weekend warror boat I don't want to take a chance of a problem at high speed.

Now I just need a good deal on a dual rotary helm and the bracket I need to mount it to my engine. And I figures I had one here not to long ago but sold it. Bummer

[BarryStrawn]

Lee - Use your best judgement but the cable/pulley is real nice. Main problem is it may spoil you to running fast using anything with less feel. If you have the parts, I would encourage you to give it a try. Plus it is much lighter. Just post plenty of pictures when you are rigging.

On the hydraulic jack discussion - Keep in mind that the cable slack will be at least four times the amount the engine moves relative to the dash pulleys and anchors. Just make sure it is snug in the running position. Worst case is you overtighten it and the added jackplate tension fails one of the anchors or front pulleys. No fun at all. You can jack it maybe an inch before it get real sloppy.

The OPC race motors like a CCC or Mercury Champ jack on the steering pivot so the motor moves more or less straight up and down. Very different than a regular jack plate where the motor moves back on the transom angle. Plus the production motor is much higher which adds significantly to the problem. Keeping the front pulleys as high as possible will help a little. Mounting the cable anchors several feet up in the air could solve the problem but is a little impractical. A jack plate could be fabricated where the plate moved at right angles to the cables but this would require some serious wedge on both the transom and engine side of the plate.

[TTriton]

I still have plenty of time to change my mind. I guess the main factor that would change my mind is what falls in my lap. I have most of the parts for a cable pully steering exept for the steering plates for the engine. And I have nothing for the dual rotary sytem.

[woodco]

When yur runnin an Ally River Racer swingin a 32 Chopper and ya blow the boat out over a wake and the cable pulley decides to break from the mount upon re-entering the water :eek: " Right Turn Clyde " ....." OUCH "

[BarryStrawn]

Woodco - Ya that would hurt but isn't really the fault of the steering, more like the rigger didn't do his job. But you are right, cable/pulley has no redundant features. If anything breaks or comes unfastened it will be an adventure. Preflight inspection is mandatory.

[woodco]

It was a brand new boat..I mean just came from the factory.Did a good pre-flight on her but when yur testing..(I hate that word)
Ya never know what's gonna happen.I guess that's the fun part
of makin these things go faster , gotta find the flaws that can make a good day turn bad.We found out that the Ally needed a
little more re-enforcement in the dash area , and when ya turn that kinda blade it can break things.At least there were no injuries and the boat lived to run another day. :D

[Raceman]

Trim won't loosen or tighten the cables if the arms are properly designed. As somebody else said, the hydraulic up/down in a champ mid wont change the cables either. When raising the jack up, the cables tighten, not loosen, because the angle of the transom is moving the engine farther from the boat. Lee, if you get the cable/pulleys on right, you'll really like the system.

[BarryStrawn]

Woodco - Yep, we all do our part for race boat development. After I tripped and rolled my XR2002 back in '84 Darris was interested to see where she broke and if she floated. This little adventure also broke the dash reinforcement where my pulley brackets attached. Might have been from me trying to hang on to the wheel.

Raceman - Thanks for clarifying that the cables get tighter when the motor goes up. What do you think of those extended rear pulley arms for the shortshaft Mercurys? They must be 7 or 8 inches long. I suppose this is because of the added setback in the bracket. It looks like there would be a lot of leverage when you get them trimmed way up or down. Seem to work OK. To bad Mercury didn't design the steering and tilt pivot closer together. I really like the way the Champ guys are doing it now with rod ends and a second plate so the pivot bolt is in double shear.

[Raceman]

I haven't seen the new ones Barry. I have had some bad experiences with steering arms myself. My first 15 Allison required a 4" upward offset in the arms when I put the T3 on it (early champ housing for anybody unfamiliar) Trimming the engine up put so much slack in the cable that one side would almost touch the bottom of the boat when it was first put on. By somewhat limiting the trim travel, combined with the fact that the boat had no steering torque because of the speedmaster it was manageable. One of my STV's came with cable/pulley also, and although the arms were professionally made, they didn't extend close enough to the swivel axis and as a result the cable tension changed greatly when turned very far off center. When I bought the 2001 Allison drag in '96, the T4 again required the offset arms to keep from cutting the boat all to pieces. I made a double pulleyed, spring loaded loop, similar to a loaded block and tackle to run the cable on the slack side through. Unfortunately I forgot that the #8 SSM rotated the prop backwards and stuck it on the wrong side, so had to re do the whole thing. It made it a lot better, but I'd still hate to be in a marginal situation and have those springs in the system. If I ever do another short one, I'm butchering the boat and doing the arms right.