Just curious what you guys are doing for your throttle cables.

I have been using your basic yellow nyrod with braided cable back to an easy connector on the servo. At the throttle end, I'm using a threadded nylon ball link.

I've noticed with the longer cables (Servo behind the TE of the wing), and the cheaper small servos (Hitec 85s') were using on throttles that the barrel is not always centered. Also, with the long cable, the weight is a bit more than I like.

Any ideas??

Take up model railroads

Otherwise make sure the cable is supported for the whole lengh, or use a stffer cable, The method you mentioned is what I do

Dave for me I have had much better luck with thin piano wire about .32 or thereabouts. I also use an Ez Ajust on the servo and solder on Dubro brass threads for the clevis or ball cup. It runs in Yellow Nyrod inner tube. Much thinner and easier in cases where the tank is tight aginst the side and fexability is as good or better than the much heavier and thicker flex cables. One additional plus is its less drag than the either full Nyrod or flex cable and that means better servo resolution, centering not to mention straight nyrod getting longer and shorter with temperature.

I did have one soldered thread come loose once and that most likely due to my careless cold solder job but not since. Of course silver solder would even eliminate that.

John

Dave,

My recommendation, starting from the carb barrel:

1. Ball-link.
2. Du-Bro 12" rod, threaded at both ends.
3. 2" of yellow Nyrod.
4. More Du-Bro rod, with 1 end threaded into the Nyrod.
5. Z-bend, soldered-on clevis, or ball-link connection to the servo (depending on my mood).

The Nyrod in the middle acts as a barrier to vibration, so your servo doesn't wear out as fast. Also, in the event of a crash (which I have heard about but never experienced myself, of course, because I never crash ), the Nyrod can sometimes save the servo output wheel and/or drive gears. But because the piece of Nyrod is so short, there's no noticeable expansion/contraction with heat, and it's stiff enough to push and pull without a supporting tube. I would, however, sleeve it with outer Nyrod if there's a tight fit next to the fuel tank.

DHG

Semi-Flex cable. Running through the yellow nyrod tube. Solder the brass threaded end on and screw on the Du-Bro ball link clevis (hooks to the throttle boby). 2 ways to do the inside part..... 1) tin the cable and run it through one of those adjustable things on the servo arm, with the set screw. This allows me to switch from Nelson to Super Sport Jett 40. 2) just solder a metal clevis on, which is how all my Vortex's are done. But I only fly that plane with a Nelson, so there is no need to have any adjustablity. Just as long as it's made the correct length to start....

As always though.... 20 ways to skin that kitty...

Randy

Try something really simple. .072 threaded on one end 2-56 pushrod, start w/30" length. On servo end, Sullivan 2-56 clevis, for adjustment, on throttle end, cut to length and solder on either ball joint or another clevis. Been doing it for years, and no support needed.


Bryant

Well, my current setup is nearly identical to Randy's so I must be doing something right.

I'm still not sure it is the best way to do it, but none of the other suggestions seem much better to me.

I'd love to shove the throttle servo in the nose in front of the tank, with a very short cable to the carb, but I want decent access, and this doesn't sound all that convenient to make adjustments.

Just curious, like it has been said. There has got to be a better way to skin the cat.

Thanks for your ideas.

Dave,
Lock the barrel open and use a fuel shut off like on Q40s. I personaly don't do it but it would eliminate the problem you are talking about. I am thinking of switching to this method. I now use golden rod with a ball link and EZ conector on the servo with no real concerns

Lee

Lee,

I just did that on my last Seeker.

After 5 flights the throttle servo stopped working. It was a brand new Hitec 85. I was using very soft fuel line, and had the endpoints set up so that the servo should not have hung up anywhere. Not sure if it was a bad servo or my method. I would hate to have this happen at the line of a big race, so I am trying to re-think this.

I haven't had a mechanical problem with the cable method, just thought there was a better way???

I usually use an .040 solid music wire running through a nyrod tube. It will handle reasonable routing without binding.

I solder on a threaded end for a dubro ball link.

Served me well for many years.

I have also done the throttle pinch-off using a "U" shaped end on the same rod, and pinching against the firewall or backplate mount. But expereince showed that I was much better off using the carb to shut the engine down.

Bob Brassell

Hi Dave

First, thanks for the plans of the Seeker, just need to transfer a CAD program form my office computer.

As a new Racer, please take these comments for what they are worth.

My first planes are the Lanier Predator and I installed my Hitec 81mg on the right side of the firewall compartment. I inverted the throttle servo and the pushrod comes out on the bottom right, right in line with the throttle arm. Total lenght is approx. 4 inches. My friends, who I will be racing with, have been giving me advice and the placement of the throttle servo, at trainling edge, has been of some concern to them as well. I should mention that I located the the fuel cell in the middle of the CG.

Sometimes not knowing the "right way" frees up your mind to try something different.

Again, thanks for your help and look forward to trying out a Seeker.

Steve Cannon

Steve, do you have a hatch on the nose?

I am sure your method will work fine as long as you have access to the servo if necessary. I typically avoid the MG servos on racers as they are substantially heavier, and get sloppier quite a bit faster than nylon geared servos.

I typically avoid nose hatches on planes I use to race 428 with. Nose strength and rigidity are extremely important for transfering power through the airframe. A hatch up front takes away that rigidity and power is lost through vibration.

Thanks for your comments.

Dave, Yes I do have a hatch cover. I used some servo screws to attach to formers. I did some reinforciing with 1/8" ply inside the front compartment. Attached the battery to one side and the servo to the other.

I test flew her today and had two very nice flights. Two clicks of down elevator was all the trim I needed. Quite happy with overall performance. Nice center location of tank, did not change CG from beginning to end of flight

Thanks for the suggestion to switch the MG. I happen to have a std -81 on the bench and will swirch.

Total weight came in at 3 lb. 8 oz. dry.

First race on May 1, at Bowie, Md. Will get a better idea how well she flys then.

Thanks again

Steve