Is there a good waterproof way of setting up the stearing and retractable water rudder servos "in the floats"?

I'm trying to avoid the pulley / rigging setup (if possible). I'm new to the seaplane thing so I don't know what's the right or best way to do it.

Any help is much appreciated.

Howdy W.M.,
Even "full scale" float planes use cables, installing a system IN the float is just complicating matters, K.I.S.S.

You not only have to cut a hatch in the float to install a servo tray and servo but you would have to make the hatch removable and waterproof. Wherever the push rod or cables exit the float to get to the rudder, those holes would have to be waterproof as well.

What KIND of floats? Cut a hole (snug fit) close to the rear float strut so you can run the servo leeds up the strut too the fuse, mount the servo in the float and seal all around with GOOO, silicone paste, run a single push rod to the rudder, Y-harness to the air rudder and yer done.

Be sure you use a waterproof servo, they have a seal around the output spline.

I've used a Golden-rod push rod on more than a few floaters connected to the air rudder, no extra servo needed, very simple.

Here's a couple of photos of two ways that I have dealt with the water rudder issue. One is in the float - and I have never used a 'waterproof' servo and never had a problem - and the other is using an externally mounted servo on the fuselage and this is connected to the 'air' rudder via a control rod and also - when the plane is on floats - to the water rudder via a Sullivan Gold 'N Rod. Both have worked very well for me.

Here's the set-up I'm currently using. This one works very well. Tried burying the servos in the float, not good. These servos are HiTec "water resistant". One retract servo, one regular servo, way over powered but these were the only "water resistant" servos in the LHS at the time.

Easy to do. When you install the servo, use a large balloon trimmed to encase the servo. Cut an additional small slit for the servo wires to exit and use the original hole for the pushrod to exit. After putting the wires and pushrod through their respective holes, use dental floss to tie the balloon material down snug to the wire leads and the pushrod respectively. On the pushrod exit, leave enough slack balloon material to allow free movement, like a bellows assembly. You end up with a servo in a balloon "bag" with two things exiting the bag... the servo wires and the pushrod. This seals the whole shooting match well enough to work even in salt water. It will not survive a prolonged submersion, but then neither will most anything in a model aircraft. It will be totally spray-proof.

Tom

The balloon trick is clever.

All that is SO much more work than rigging a proper set of cables, and with the servo in the float you'll have the servo wires looking like a scale set of heavy-duty jumper cables hanging out of the plane.

I have used Sullivan GoldNRods, but have never found that they are precise when bending much. They are great when run nearly straight, and the thing about temperature instability is only a ssymptom of incorrect installation. The 180-degree bend has lost motion and a lot of friction which causes poor centering, so the water rudders only point in the same direction as the air rudders by coincidence. ANd a big loop of goldnrod hanging out of the side of the plane is even less aesthetically appealing than the servo leads. If you find it necessary to use goldnrod, it works much better to run a nearly straight assembly from the nose-wheel tiller bar back to the water rudder arm.

Au contraire Jim, I beg to differ.

By the way, the "balloon" does not have to literally be a balloon. I use latex gloves now, although used balloons in the past. The fingers of the glove are especially easy to tie off. It is super quick to do, much easier than rigging up cables with their attendant fussiness.

The trick is SO easy to do, I usually use it for the electronics installation inside the airplane too, especially for those I fly in salt water.

The 'jumper cable' look might be a problem on very small airplanes, but is not noticiable on anything say, .15 sized, or larger. Tie the wires off to a strut.

Tom

I've never had the problems that JimCasey mentions when using Gold 'N Rods with a 180 degree turn in them, perhaps due to me ensuring a smooth curve that's not a small radius. I've not had problems with the 'in the float' servo mounting method - though I will remember the balloon/glove method in the future, so thanks T_ om - and since I've never seen a full scale Extra 300XS, Dazzler, Balsa USA Stingray, etc. (like I fly) on floats I'm not too concerned about a Top Gun scale appearance.

OK, Jump on me. Like my wife says, I am sometimes wrong, but never in doubt.

I appreciate all the replies and ideas.

I thought that maybe there was some kind of water proof boot that would mount on the back of the float(s) sealing a push rod exiting the back of the float.

I'm building a KMP Beaver so I'd like to keep it some what scale. But, As I never seen up close how a full scale is rigged up, I'm assuming I would have to run 8 cables up to the plane for a dual water rudder setup.

2 for each rudder - pull / pull and 2 for retracting water rudders pull/ pull. Please correct me if I'm wrong. ( this is why I asked my original question)

I found a good web site on Beavers pics but have yet to find a close up on the cable rigging for the plane.

I'd like to keep it simple but definitely no nyrod looping down the outside.

Not mine!

WOW! THat's a PRETTY Beaver.
Here's one that was built by a friend of mine:


Going back a post or 2: 2 cables for each rudder for steering. One for retract. THe retract feature is optional as long as the WR is spring-loaded down. ANd you really only need one water rudder.

How do you securely mount a fully balloon-covered servo?

Hi

I believe multiplex do a waterproof servo (the MS11) which theoretically you could mount in the float, although iv'e never actually tried one.

Can't find a link where you could buy one, might not be current.

Simon

Hi again

alternatively pick up a cheap servo from a swapmeet prob a couple of quid or so when installed lather it in vasoline and use it until it fails.

Then repeat process and use failed servo for spares.

Simon

You just screw it down to a pair of rails fore and aft, just as you would mount any servo. Screwing right through the latex glove or balloon material. Use small washers over the head of the screws so as not to tear the material and you are done. The screw and washer pressing down on the latex seals it tight.

Tom

Great idea - I am going to try this. I have a "waterproof" servo but I would feel better about some extra protection.

How do you handle getting the control arm or rod out of the balloon?

I am in the process of putting a 1/4 scale monocoupe on floats. I plan on rigging wires for the retract and steering of the water rudders. I built the great planes floats because they were inexpensive and I don't mind building. I thought about servos in the floats. It just seemed like too much work for something this small (1/4 scale). I also didn't want any extra weight aft of the CG since many float planes require weight in the front of the floats to balance. Obviously the wires are the most scale looking. It is difficult to make servos in the floats look scale. The other nice thing about the wires is that all of the adjustments are made outside the floats and the airplane, with fairly easy access. If you aren't going for the scale look, then the servo in the float might work. I ordered my pulleys from Tower. I drew up my planned rig so I knew exactly how many pulleys to order (they aren't cheap). I am going with a closed loop for the steering. This will require two cables from the rudder setup down to the floats. The other water rudder steering input arms will run through pulleys to the other arm of the other water rudder. For retract, each float will have a wire coming from the aircraft to the float. A total of 4 wires will go from aircraft to float. Two more wires will go from water rudder to water rudder, for a total of six wires. It sounds much more confusing than it is. Using the correct fishing line (fluoro), everything should be tight enough to prevent slop. We'll see!

As a side note, I am in the dreaming/planning process of putting something larger on floats and trying to install a retract system in the float. Obviously it will need to be large to handle the weight. I need to get my coupe finished before I dream too big!