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General control line discussion => Open Forum => Topic started by: Tim Wescott on August 13, 2010, 07:43:59 PM
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I'm down to details -- control system, hinging, covering, paint, etc. I still have to figure out the weight box for the tail -- I'm thinking I'll just drill a 1" hole in the back, and put a 1/32" or 1/16" plywood lid on it.
It's a Sonex Waiex (Waiex? Why not?), very semi-scale. That's an OS Max 25 in the nose. I don't know how it'll fly, but hopefully it'll hang together long enough for me to learn the beginner's pattern.
http://www.sonexaircraft.com/aircraft/waiex.html
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Very interesting, Tim. What kind of control hookup do you have on that V-tail? Show us a pic...
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Now that's a cool looking model.
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Very interesting, Tim. What kind of control hookup do you have on that V-tail? Show us a pic...
Y'know, it's funny you should ask that...
Nothing at all right now -- so you have the picture! I'm going to KISS and put horns on both the right and left flaps, with separate push rods back to the tail. The only viable alternative I can see is to use a forked elevator rod off of the right flap, with a slot in the fuse someplace, and lingering worry about binding and the two rather humongous elevators not working in synchrony. I don't want to go there, so I'm just going to spend a bit of weight in return for some peace of mind.
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The elevator hookup is dead simple. Use the lucky boxes just like you would on the flaps. One horn, one pushrod, piece of cake. If you do not know what these are just ask around, if you can't find someone to show you what these are let me know and I will describe how they work. They do work every time and are super easy to make. RJ
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Bob,
I don't know because I've never actually built or used a set, but wouldn't the vee on this model be kind of aggressive for lucky boxes?
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Hmm. I'll have to think about the lucky boxes -- the real issue I'd have with them now is that the elevators are already built, so I'd have to do some surgery to get them in.
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"Lucky boxes" work great for swept angles but in the same (geometric) plane...not sure how you could set them up for the V-tail.
I put a horn on each elevator, and soldered a "tee" on the end of the pushrod; the horns could slide inward and outward on the arms of the tee as it moved from "up" to "down". But it was on a 1/2A; dunno if it could be made rigid enough on a big plane. Something to try anyhow.
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"Lucky boxes" work great for swept angles but in the same (geometric) plane...not sure how you could set them up for the V-tail.
I see no reason why some dihedral in the tail, per se, should be a problem. But that's an awful lot of sideways motion that the lucky box would have to accomodate without binding.
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Okay Guys, Here's how it works. It is dead simple and really easy to do. You put a box in each elevator as close as you can to the inside part of the elevator, meaning the end of the elevator. Keep the horn as short as possible spanwise and angle the part of the horn that goes into the boxes. The amount of movement of the wire in the box is directly related to how small or large the angle is . On a wing it isn't much but on the stab you're probably looking at 30-40 degrees. It works just as well as the flaps, just moves a little more. Be sure to use phenolic or fiberglass as the sandwich or the top and bottom of the box, will last longer than the plane. It is rediculously simple and works everytime and no play in the system. RJ
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Gotta go with Alfadawg here. The *lucky boxes* are super simple, and work. His suggestion on what to line them with is a great idea. Phenolic is my choice.
Big Bear
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Pardon my confusion -- you don't have 1000 words, so I can't quite build up one picture.
(snip)
Keep the horn as short as possible spanwise and angle the part of the horn that goes into the boxes.
Angle how? Do you mean instead of bending the wire into a square U with 90 degree bends I should bend it less? More?
The amount of movement of the wire in the box is directly related to how small or large the angle is .
I assume that you mean that dihedral of the tail is the "angle" you're quoting here?
I keep trying to visualize this, and the two problems I have with it are that (1), I'd need to set it above the point of the 'V' in the stab so the wires go into the center of the elevator halves, and (2), the obvious place for the elevator horn is centered horizontally, but on a profile that's right over a whole bunch of balsa wood.
On a wing it isn't much but on the stab you're probably looking at 30-40 degrees. It works just as well as the flaps, just moves a little more. Be sure to use phenolic or fiberglass as the sandwich or the top and bottom of the box, will last longer than the plane.
I assume you mean as opposed to plywood, rather than as opposed to brass or steel (nice spring steel would certainly wear well...)
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sGood questions. Yes, the elevator wire should be bent not with 90 degree bends but about 75 degrees on each. The slot in the elevators will dictate how high the horn will be above the v-joint. That is why you need to keep the two arms that go into the elevators as close together as possible to keep the horizontal or middle part of the horn as close to the vee as possible. Yeah, it will be above the joint such that a notch is needed in the fillet that you have between the two halves.
The angle is the amount of dihedral that you use.
Yes. You can use steel for the top and bottom of the boxes if you can stand the weight penalty. I see two problems though. How do you glue them together plus you may get a high freq vibration just where you don't need it.
Seriously, this is a really good way to do this and as I said it is super simple to do once you understand the principle. RJ
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Yes. You can use steel for the top and bottom of the boxes if you can stand the weight penalty. I see two problems though. How do you glue them together plus you may get a high freq vibration just where you don't need it.
I've got some 1/32" circuit board material -- that's probably what I'll use.
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It's coming out tail heavy! Oh the humanity!
Balance point is about 1/4" behind the spar in the as-shown condition. Even if the tank were made from lead I don't think it'd bring the balance point that far forward. And here I just finished making a nifty weight box (I drilled 2/3 of the way through the fuse with a 1-1/4" Forstner bit, then made a cover).
Oh well -- if there's a rev 2, it'll have a longer nose.
And the control system works well.
So I just need to sort out the wheel location (they're 1" back from 'correct', silly me) and maybe I can start painting!
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Extend the nose at least an inch. H^^ Steve
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Extend the nose at least an inch.
Grr. I hate to cut it up, but that's probably what I need to do.
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Extend the nose at least an inch.
I still haven't decided whether to kiss you or smack you, Steve.
There isn't enough meat to extend the nose an inch without major surgery (I am not stripping the doublers off!). But I'm moving the motor forward by the mounting hole spacing (14mm), putting the motor's back mounting holes on the former front mounting holes in the fuse. Cut, fit, glue, sand -- how is it that I always end up doing crash repair before the plane is even flying?
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Bolt an Evolution 36 in the nose with the big muffler. That should balance it.
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Bolt an Evolution 36 in the nose with the big muffler. That should balance it.
Given that it's designed for an OS Max 25, and only carries 410 squares, the flight results would certainly be interesting.
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Tim... it is going to be yellow isn't it?
.... with the flames around the header opening?
bob branch
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Tim... it is going to be yellow isn't it?
.... with the flames around the header opening?
bob branch
We'll see if my ambition holds out the closer it gets to flyable. Here's my inspiration:
http://www.sonexaircraft.com/images/products/waiex/waiexgallery.html
Some proportions may have changed, to make the thing actually capable of the AMA stunt pattern...
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Tim
Yup, 12YX is the bird I was thinking of. Hope you have been to Oshkosh and seen it. It is stunning.
bob branch
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Extend the nose at least an inch.
The elevator hookup is dead simple. Use the lucky boxes just like you would on the flaps. One horn, one pushrod, piece of cake.
Steve, Bob -- thank you for shaming me into doing the right things on this. I actually built the thing without the lucky boxes in the tail, but dangit, nothing seemed to work right -- and I think it'll be lighter back there with just one elevator push rod, which should help balance it without adding too much weight.
The lucky boxes are plywood, by the way -- I started making them with G10 fiberglass, but it's just too dang hard to work. We'll see how plywood lasts. It only took me two tries before I managed a right and a left side.
I only extended the nose by 14mm, though -- I think I'll regret that, but I can polish the nifty brass spinner and say I did it on purpose, can't I?
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HI Tim,
You can always fill up the engine's back plate with lead.
Big Bear
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Why, oh why, didn't I just build a stupid kit that already had everything figured out? Or find plans for a Ringmaster, or something?
I just epoxied the wing in place in the fuse, soon I'll be putting Minwax on the fuselage*. If I luck out I'll get to fly it this year, before the weather closes in. If I'm really lucky, I won't crash it before I get a chance to do one whole Beginner's Pattern with it.
* This is someone's cue for telling me I'm doing it out of order -- I don't care; I'd thought about finishing fuse and wing separately, and there were just too many details I couldn't reconcile. This really does make more sense, at least for this model.
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What ever works for you, go with it. Everybody has their way of doing things. I learned in competition in the early years, if someone tells you to do this, you try it at a practice session. If it works, you use it. If not you file it away as it may work at a later time and different circumstances. Every body kept telling me to run 8X8 props in rat racing. I tried it, but what worked for me was 9X7 in the heats and 9X8 in the finals. This goes for building and finishing also. I am finishing the basic construction on a wing that has not seen a jig yet. Some of my straightest wings have never seen a jig. H^^
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" I am finishing the basic construction on a wing that has not seen a jig yet. Some of my straightest wings have never seen a jig."
Doc...Maybe the trick is to build them in the jig, and not just show it to 'em? :## Or maybe your jig base isn't as straight as it had orta be. H^^ Steve
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Tale -o- the tape:
Ready for finish (yay!)
Weight with structure, stuff in the wing, flaps, flap pushrod, tail, no tail pushrod: 1 pound.
Pile everything from my "to be put on the plane" box, including engine and tank: 1 pound, 11.5 oz.
So if I'm really lucky I should hold it down to 2 pounds. Hah! That'll be the day. I'm expecting to need nose weight, so it'll probably be a bit more but hopefully not too. I'm sure the fact that it'll be bright yellow will make it fly better, though.
This is on a 48" span*, 405 square inch area plane with OS Max 25 for power.
* It was supposed to be 45 inches, but some fool only half designed the wing, without taking the size of the tips into account. So the chord got thinned from 9" down to 8.75 by narrowing up the flaps, the aspect ratio went up a bit**, and the build progressed.
** Just what I need in the windy Willamette valley, I'm sure.