Outboard Newbie Here

[fletch51]

I am rebuilding a vee hull with O/B engine for an old friend that is also new to boats.

It is a used boat he got somewhere and it has a old K&B 7.5 that runs great.

The main reason for the rebuild of the boat is the homeade radio box that has no seals of any kind.

As I was planning the pushrod layout, I figured since the Hitec 805 servo horn has such long arms that it might make the pushrods move horizontally further than the pushrod seal base will allow.

It may already be common, but I had a thought that criss-crossing the linkages would reduce lateral movement and keep the linkages from rubbing the seal base and exit holes in the hull.

I understand that if the steel 4-40 linkages rub each other it might interfere even with the spekturm 2.4ghz radio. I plan to isolate that contact.

Can someone let me know if this criss-crossing idea is bad/good or even possible?

Thanks, Fletcher Grosz J.A.N.

(Just Another Newb)

 

[Jerry Dunlap]

If you use two 4-40 rods for steering and a servo with at least 120 oz. of torque you can run them straight. I suppose you could criss cross linkages, not sure what the advantage would be. Never even entered my mind to try that, but hell lots of things have never entered my mind.

JD

 

[fletch51]

I appreciate the feedback Jerry.

I am worried about the lateral movement of the pushrods causing rubbing on the hull exits and/or the radio box exits because of those long servo horn arms, that I am not used to.It is not that I am worried about servo torque, it's a quarter scale servo with something like 340oz/in torque.

I can find out the hard way by setting it up one way, and if it rubs, then fiberglassing the holes(exits) and redrilling it, to try it the other way.

Thats why I am asking here, the experience of the members on this website is quite impressive.

Thanks, Fletch

 

[Jerry Dunlap]

Just because the servo control arms are long does not mean you need/want to position the linkages in the outter holes. You can probably control the boat just fine with the linkages in the second or third hole out from the center. Too much rudder throw will create handling problems in the turns.

JD

 

[fletch51]

Is it OK to use the full limit of the K&B transom mount left/right limits?

 

[topfuel443]

Its physically ok, but you will NOT need any where near that much travel. What Jerry suggested is by far sufficient.

~James

 

[moparbarn]

fletch, i can only agree with jd & top, what looks like very little steering throw on the bench is probably enough. i you allow for full travel, the boat will/can hook or spin out very easily. been there, done that........

 

[fletch51]

Thanks all.

Will do.

Fletch