Hey guys.
I was on Tower Hobbies website and came across a Great Planes control horn that might work!
It is Tower Special Stock# LXEVC9. Take a look and see what you think.
Greg

The only "Bias" I witnessed so far has been "against my poor flying ability"
Eddie

Greg, that is the idea. The issue is the black "control attachment" parts are the problem. Because of the taper on the Excelleron (and many other airplanes)'s elevators, if you use pull pull, the take off point gets too far behind the hinge line. THis creates problems in varying tension on the surface, particularly the farther in deflection you get. The perfect setup is to have the clevis take off point EXACTLY over the center of the hinge line.

That's what those nifty long Dubro parts will permit, because they are so long. Dang it.

Bob,
Does it look look the Great Planes parts would be a step up from stock, given that they are a few mm longer, or would it be worth messing with?
Greg

Good point. Don't know. Mine look like they will need about 3/16", maybe a little more. It's pretty cheap to find out, though.

Eddie - "bias" is the unspoken-of phenomenon that occurs when you put humans in charge of subjective, comparative assessments. Perhaps you're correct, and I hope so. My experience has proven otherwise....I've observed "4 cycle bias", I've observed "name bias", I've observed "no name bias", "airplane bias", and yes, even "age bias".

Personally, I do not believe TRUE objectivity exists; even in the finest of judges. Our analog brains are not automaton-based. We cannot ever COMPLETELY eliminate behavior, attitude, or opinion-based aspects from creeping in.
Besides - the best judge in the world is still making a score based on what *he* thinks it's supposed to be. I'm sure you all haven't been surprised by the number of "45 degree" lines that are available for a variety of scores

Regarding the control takeoffs, it is not only pull-pull that is affected. If you don't have the pivot point on the hinge line, you will get differential in your throws. More up than down, etc.

The ARF I am working on, a CA Model's Epsilon, the center of the hard point's are located 13 mm behind the hinge line. Therefore, I need takeoffs that long to get the pivot point over the hinge line. I haven't been able to find any that long except in the Dubro control horn packs.

Maybe my geometry knowledge is not as sharp as it should be but it seems to me
unless the control horn itself is mounted directly 90 deg on the hinge line there will
be some differential no matter where the cable attaching point is extended to.

tommy s

Maybe what we have to do - imagine my SHOCK - is *buy* the whole Dubro setup. We're "pattern people", after all. We're the guys that will pay $200 for something that took $2 to make. I should be ASHAMED of myself for trying to save a buck (and conserve resources by not buying stuff that I'll just throw away). Shame on me.

I'm gonna place a Tower Order for the "real" Dubro setup and be done with it. Sometimes, we just have to give in.

Nope. it really is a function of the connection point (pivot point) for the clevis pin. The pivot point it what is rotating through the arc when the control surface moves. If that point is exactly over the hinge line, then it rotates in a constant radius from the hinge line.

That's what this is all about.

Pattern noob time!!!

I've reached a decision in my flying style. I've been flying around aimlessly (pun intended) and I want to learn to do the precision, 'pattern', style of flying. From reading all of this thread, I've come to the conclusion that the Excelleron 90 may be a good choice for me. Thanks for all of the great info BTW.

Most of you are using either 2 strokes of YS 110's. I have a Magnum 1.20 4 stroke and a Saito 100 available to power it. I have no doubts the Magnum would power it fine based on the AU weights listed earlier but,,, the Mag 120 is a pretty heavy engine. On the other hand, the Saito is very light but, may have a power problem in this application. I feel that either will probably need lead to balance out the plane.

Whch engine should I use? The 120 and possibly add more weight to the tail to balance or the 100 and have to add nose weight and risk being underpowered??

Thanks for all of the insights guys, I'm already learning....[8D]

Dave,
The Magnum 1.20 is the engine Global recommends for the Excelleron so it should be fine.
With the YS 1.10 I actually had to add a few ounces to the nose to balance it.

tommy s

Okay, guys. Here's the "Exhaust System Install" progress. Made the canister cradle from edge-grain balsa, laminated in ply, lined with silicon pad, then epoxied to the wing center section, bottom. It is shown with the KS canister laying on it, and will be secured using O-rings (on order) that will go from screw, over canister, then onto other screw. Done this in the past, and works well. The cradle weighs 4 grams.

When I get the header, I'll assemble the whole thing, coupler, pipe inlet extension, and everything and do pics.

My reply from Dubro. I had used the #867 as an example.

Hello John,

The 867 is molded with both the threaded arm and washer, both would have to be purchased together. There is a fifty dollar minimum, which you would receive sixteen pieces.

Best regards,

Terry

aerobob,

If you are going to buy the whole set, take a look at the #912. Tower doesn't have pictures, but Dubro's site does. This setup allows for the bearing surface to be flush with the control surface and the 6-32 bolt to be perpendicular to the hing line on surfaces that have a taper. I bought one to try it and it works well.

It is not a matter of money, rather of principle. Why buy more than you need? And those $5 here and there do add up after a while.

A general rudder pull-pull question:

In setting up a pull-pull rudder, how do you get it done without the cables rubbing on something. Seems like every time I try to set it up, no matter what I do, I get some rubbing somewhere, either on the exit holes or a former somewhere. Unless of course I make the exit holes extremely long. I've tried straight shots, crossing the cables, varying the length of the servo arm, etc. So then do you simply let them rub or put them in tubes? Just wondering if I'm the only one with this problem. Thanks.

guys what is the correct dubro part number for the control horn.

I've got to stop reading RCU. Just when I think I have my plane habit under control, a thread like this pops up. You guys are costing me a fortune!

With any luck I'll start assembling my new Excelleron this weekend. I'm following Aerobob's lead and installing a ST 2300. Thanks for such a great thread and for feeding my habit.

PS: Aerobob, thanks for spreading the word about the pipes.

Ric,
You certainly are not alone. My Excelleron arrived this afternoon.

<I've got to stop reading RCU. Just when I think I have my plane habit under control, a thread like this pops up. You guys are costing me a fortune!>

Bill

Bobby,
The control horns I am going to order are Dubro #867 you can find them on Tower Hobbies under stock#LXEMF9.
Greg

Thanks Greg

Can't remember if I told anyone - if you do the ST2300, you MUST reduce the length of the mounting lugs ON THE MOTOR!!!! to make the stock mount work. I have pics in this thread someplace, and explanation/pics on my website.

In addition, you must take just about 1 mm off of EACH of the hardwood beams to permit everything to line up.
I really do NOT recommend a piped setup with this motor, guys. It will simply be too, TOO much. Just get a canister muffler, or make your own (instructions on my webpage) and muffle it. That also permits you to just modify the tunnel, and not hack into the fuselage to modify it.

One other point - new Excelleron guys - gently remove and THROW AWAY the steel hinges supplied. Particularly if you're doing the ST 2300. Buy Sig "EZ" Hinges (as they are thick enough to use the slots already in the bird), and they are very reliable. Do the "draw a line with a pencil on both sides of each hinge across the hinge center at it's flex point" thing.

Finally - Don't even bother with a 7" CG. It is FAR too nose heavy.

Hey Bob,

What is the problem with the steel hinges? I'm not familiar with them, is it the fact that they are steel and are prone to rusting or failure?

Thanks,

Ken

Tommy, Is the mount that comes with it like the Dave Brown? Does it dampen the vibes enough on the YS 110?
Tom

Several factors influence my choice, and it's a matter of opinion/experience.
1. Metal hinges develop slop much more rapidly.
2. Metal hinges with metal pins provide metal to metal vibration (e.g. electrical "noise")
3. Loose hinges that are too free CAN be prone to flutter.
4. Weight - all of the hinges in the box weighed just over 1.2 oz. Equiv. CA hinges, about 8 grams.
5. (and my MAIN reason) - ease of installation. Putzing around with epoxy, waiting to dry, holding things in place, lubricating the hinges...not me. EZ hinge - install in control surface side. Small drop of ca on one corner to hold in place. Insert into main flying surface. Drip CA on hinges from top. Wait 10 secs. Turn over, drip ca on other side. Wait 10 secs. DONE.

YMMV, and remember these are IMHO.

Got it, on all points.

Thanks pal,

Ken

Merry Christmas and a Happy New Year.