Scale control surface
05-19-2020, 09:15 PM
#51
I considered a film covering at first but as my Cessna progresses (wing almost done, tail finished) I find myself so happy with it, that I’ll finish it properly (silkspan, dope and paint) but will follow your good advice of adding the strips last.
BTW has anyone considered changing those thick balsa ailerons to built up ones? They seem unnecessarily heavy...
BTW has anyone considered changing those thick balsa ailerons to built up ones? They seem unnecessarily heavy...
05-19-2020, 11:25 PM
#52
I considered a film covering at first but as my Cessna progresses (wing almost done, tail finished) I find myself so happy with it, that I’ll finish it properly (silkspan, dope and paint) but will follow your good advice of adding the strips last.
BTW has anyone considered changing those thick balsa ailerons to built up ones? They seem unnecessarily heavy...
BTW has anyone considered changing those thick balsa ailerons to built up ones? They seem unnecessarily heavy...
The solid aileron facilitates in mounting such a hinge arrangement and also provides an uncomplicated anchor point for the ball end of a ball link within the leading edge of the aileron as in the real aircraft and eliminates the control horn. That means completely hidden pushrods full scale style.
For hinges I'll be using three segments of miniature piano hinge replicating the full scale hinges.
Obviously my main concern is fidelity to scale, but if you happen to be more practical than I am, you'll find it pretty easy to fabricate a built up aileron to save a bit of weight. At the same time, I've never heard any complaints about this model's performance due to weight.
05-19-2020, 11:48 PM
#53
Very good idea on the aileron top hinging! (I’ve done just that on my large Pica T-28 flaps).
The kit aileron V shaped LE design does look too much like a sport model, I’ll change to top hinges so at least from above it’ll look far better.
The heavy ailerons will also increase the moment of inertia in roll but so what, I plan on flying it like a Cessna anyway.
The kit aileron V shaped LE design does look too much like a sport model, I’ll change to top hinges so at least from above it’ll look far better.
The heavy ailerons will also increase the moment of inertia in roll but so what, I plan on flying it like a Cessna anyway.
05-20-2020, 08:41 PM
#54
Very good idea on the aileron top hinging! (I’ve done just that on my large Pica T-28 flaps).
The kit aileron V shaped LE design does look too much like a sport model, I’ll change to top hinges so at least from above it’ll look far better.
The heavy ailerons will also increase the moment of inertia in roll but so what, I plan on flying it like a Cessna anyway.
The kit aileron V shaped LE design does look too much like a sport model, I’ll change to top hinges so at least from above it’ll look far better.
The heavy ailerons will also increase the moment of inertia in roll but so what, I plan on flying it like a Cessna anyway.
05-20-2020, 08:55 PM
#55
Continued working on the ailerons last night and concluded that a change to built up ones will not make a significant difference relative to the complete model weight (about 40-50 grams difference).
However, did note two other points to consider:
The option of a ball link embedded in the bottom of the LE, and thus invisible push rod, won’t work in this case because the aileron is not deep enough. The distance from hinge to ball link is too small and there’s a high risk of flutter, so I’ll top hinge the aileron but use a standard horn, maybe just shortened a bit.
The other thing in favor of the solid aileron is the fact you need to shape it to conform to the washout.
TF makes no mention of this, but a flat aileron will either cause a ‘step’ between flap and aileron TEs, or if you eliminate the step, you loose some washout at the tip. So I’ll shape a small twist in the aileron to properly accommodate the washout.
However, did note two other points to consider:
The option of a ball link embedded in the bottom of the LE, and thus invisible push rod, won’t work in this case because the aileron is not deep enough. The distance from hinge to ball link is too small and there’s a high risk of flutter, so I’ll top hinge the aileron but use a standard horn, maybe just shortened a bit.
The other thing in favor of the solid aileron is the fact you need to shape it to conform to the washout.
TF makes no mention of this, but a flat aileron will either cause a ‘step’ between flap and aileron TEs, or if you eliminate the step, you loose some washout at the tip. So I’ll shape a small twist in the aileron to properly accommodate the washout.
Last edited by EF; 05-20-2020 at 09:05 PM.
05-20-2020, 11:34 PM
#56
Continued working on the ailerons last night and concluded that a change to built up ones will not make a significant difference relative to the complete model weight (about 40-50 grams difference).
However, did note two other points to consider:
The option of a ball link embedded in the bottom of the LE, and thus invisible push rod, won’t work in this case because the aileron is not deep enough. The distance from hinge to ball link is too small and there’s a high risk of flutter, so I’ll top hinge the aileron but use a standard horn, maybe just shortened a bit.
The other thing in favor of the solid aileron is the fact you need to shape it to conform to the washout.
TF makes no mention of this, but a flat aileron will either cause a ‘step’ between flap and aileron TEs, or if you eliminate the step, you loose some washout at the tip. So I’ll shape a small twist in the aileron to properly accommodate the washout.
However, did note two other points to consider:
The option of a ball link embedded in the bottom of the LE, and thus invisible push rod, won’t work in this case because the aileron is not deep enough. The distance from hinge to ball link is too small and there’s a high risk of flutter, so I’ll top hinge the aileron but use a standard horn, maybe just shortened a bit.
The other thing in favor of the solid aileron is the fact you need to shape it to conform to the washout.
TF makes no mention of this, but a flat aileron will either cause a ‘step’ between flap and aileron TEs, or if you eliminate the step, you loose some washout at the tip. So I’ll shape a small twist in the aileron to properly accommodate the washout.
This is exactly one of those things about the kit that will give an inexperienced builder some less than happy results. Another (I think ridiculous) bugaboo in this kit is the surface discontinuity between the dorsal fin and the vertical stabilizer. According to the number of fishy results I've seen done in this area, I guess not too many builders are aware of what a real 182 looks like or care about it.
Actually, depending on the level of detail and the degree to which you build it as a SCALE model, the instructions in the kit become more of a reference material than something to follow step by step.
Last edited by airsteve172; 05-20-2020 at 11:49 PM.
05-21-2020, 04:33 AM
#57
If you want a hidden control rod why not try a rotarl Drive System? Here is a link to a TF Bonanza being built with this type of system.
Mike
TF Beechcraft Bonanza F33A Build
Here is are a couple of links explaining how it works.
Harley Michaelis' RADS Design
http://www.ledametrix.com/gcs/rds.htm
Mike
TF Beechcraft Bonanza F33A Build
Here is are a couple of links explaining how it works.
Harley Michaelis' RADS Design
http://www.ledametrix.com/gcs/rds.htm
Last edited by FlyerInOKC; 05-21-2020 at 04:35 AM.
05-21-2020, 05:33 AM
#58
If you want a hidden control rod why not try a rotarl Drive System? Here is a link to a TF Bonanza being built with this type of system.
Mike
TF Beechcraft Bonanza F33A Build
Here is are a couple of links explaining how it works.
Harley Michaelis' RADS Design
http://www.ledametrix.com/gcs/rds.htm
Mike
TF Beechcraft Bonanza F33A Build
Here is are a couple of links explaining how it works.
Harley Michaelis' RADS Design
http://www.ledametrix.com/gcs/rds.htm
I have seen it used more often on specialised very high performance sailplanes, where it usually comes already incorporated in the structure by a top manufacturer, but rarely seen it used successfully on an i.c. powered (vibrating) self-built model.
I suspect, considering the workshop equipment required to make it, the fiddly setup to get it right, maintenance and inspection, plus unknown durability and reliability (meaning actual experience in a model like I fly, not just a youtube demo), and considering I expect all my sport scale models to be first and foremost dependable every weekend fliers, it is just not worth the trouble and risk.
It looks perfect in theory, but is not widely used in practice, so possibly there’s a reason for that?
I prefer to draw a clear line at reliable daily practicality in my models, it keeps me enjoying my hobby...
Last edited by EF; 05-21-2020 at 05:40 AM.
05-24-2020, 09:15 PM
#60
“I'm incorporating something that I've never done before in any build. The ailerons are going to operate without any visible linkage. This will be accomplished using a Rotary Drive System (RDS) that has been used by the slope gliding community for some time now.”
This goes back to what I wrote about looking for actual experience of someone having used it successfully over time, on an i.c. powered model, flown frequently.
But beyond all that, the TF Cessna has solid ailerons so incorporating such a system in that, isn’t so practical.
Anyway I got my Cessna ailerons conforming very nicely to the washout now, and am proceeding happily with the build.
05-25-2020, 05:18 AM
#61
RDS not withstanding, I think anyone who is capable of building this Cessna kit is certainly capable of slicing and dicing the solid ailerons to any degree including compleletely remaking them into a built up structure.
While this is anything but a perfect kit, it does lend itself very well to making modifications and innovations and if this is to be a model that does more than resemble the real aircraft when viewed from a distance, it demands embellishment from the builder.
While this is anything but a perfect kit, it does lend itself very well to making modifications and innovations and if this is to be a model that does more than resemble the real aircraft when viewed from a distance, it demands embellishment from the builder.
05-30-2020, 11:59 PM
#63
The most significant contributors to aileron flutter in our models are the air gap between aileron and wing (easy to address during construction especially with top hinges), flying too fast (not expected with a scale Cessna, or any model I fly), and sloppy linkages that with an RDS may be more difficult to rectify than with a good traditional linkage, hence why I was asking about real flying experience with RDS and such models (I always focus on dependable long service life in my models).
10-26-2020, 02:04 PM
#64
My Feedback: (1)
On a related note, does anyone KNOW the spacing between the corregation? Specifically Cessna's? The number 3" comes to mind. I would guess that is pretty common for all Cessnas.
i am building a 1/3 scale C-170, and to me the proper spacing is very important.
i am building a 1/3 scale C-170, and to me the proper spacing is very important.
10-27-2020, 06:26 AM
#65
drop a side view image
insert a side view image into your cad program...then scale the image to the size you are building...then measure the distance from center to center
10-27-2020, 06:43 AM
#66
"Corrugations are perfectly matched to mirror the opposing skin at original 3" spacing. Our aluminum skins are completely undrilled, perfect for making your own exact skin parts, using your original skins as drill patterns."
