SoCalSal

My Feedback: (16)

Chip, I have not flown R.C. for a long time. So that is the reason I don't know a lot of the "Big Names" in this hobby. I just try to build the best I can and then I know the plane will fly. I have very few tools to work with not even a vise. But the one thing I remember is when you or the previous owners of F&M were just up the coast from me. I bought your coveing system and put it on a 60" J-3. That Plane has been in storage almost 15 years and not a singel wrinkel or bubble in the fabric PERIOD. So if anyone has any doubts about the F&M stits system don't even be afraid to try it. It does not add much if any weight over those iron on coverings and it adds SO MUCH strenght to your aircrafte you won't belive it. Besides it looks far better and the cost is not all that much over those iron on suff.

I will never use anything else on my planes. This is the real thing and it is so tough and strong. Just fallow the directions provided and you will be surprized how easy it is to apply.
Here is one pointer I use for my covering system. After you put the Polytak on and lay on the fabric, let the glue soak through the fabric and then dry good. Then BEFORE you iron out the wrinkels take some MEK and put a bit on a rag and run your finger along the seams where the glue is. This will smooth out the glue so there are very few if any "high spots" due to glue build up. Then let it dry good. NOW you can iron out the wrinkels and I tell you when it shriks up tight it will also add so much more strenght to your airframe.

chuck l

My Feedback: (17)

Steve,

Thanks for the picture, I know what to look for now. Since you have been out of RC for 15 years, have you been able to get out and fly so you have your thumbs back before flying your big, beautiful Waco?

Chuck

SoCalSal

My Feedback: (16)

No I have not had any stick time for years. But I will find somebody to help out. I'm pretty sure I can get it back in just a w minutes. If the plane is trimed and balanced well should be a piece of cake.
Steve

chuck l

My Feedback: (17)

Steve,

I'm getting ready to set the incidence on the upper wing center section. On the quarter scale the attachment points to the upper section are bonded to the bent wire strut. I thinking of using JB Weld. Assuming the third scale is the same, what did you use?

Chuck

SoCalSal

My Feedback: (16)

I used the same stuff JB Weld. Just remember to rough up the ends of the music wire where the ends go. This gives it a good "bite" I used my dremel tool with a fiber wheel on it and made several shallow cuts around the wire, kind of like the groves in a piston for the rings .

Steve

chuck l

My Feedback: (17)

Steve,

Getting the angles right is going to be fun, so I have discovered now that I'm into it. Another question is, what keeps the center section from shifting around on the bushing? I seems to me that once you know where the wing is going to sit, spacers would be in order. See the attached picture.

Chuck

SoCalSal

My Feedback: (16)

Once you get the center wing section on and after you mount the wings and RIGGING wires to it it will stay in place. Also those 2 cross brace rigging wires that are between the cabne struts will help the cabnes from shifting around. I had the same thoughts when I got to that point. But after I did a mock up of the wings including the "N" struts mounted nothing moved out of its place, even without the rigging wires.

Peter Barth is a master modler and a aerospace engineer working on the Eurofighter. I trust he knows what he designed, after all he also flys these things. He better know what he is doing...... I have all most $6500 in this kit and I don't want it to do anything silly during flight.
But as you know, you can make addtional mods on any kit without hurting it like maybe putting in a spacer where you showed me, a piece of brass tubing would do if that makes you feel better.

Steve

chuck l

My Feedback: (17)

Steve,

Thanks for the reply, I won't worry about the possible shifting until the plane is assembled with the rigging in place. Do you by any chance have a close up picture of your rigging wire connections, specificallyhow you attached the non turn buckle end to the wing?

I just bonded the forward Baldachin struts with JB Weld and will do the rears tomorrow after the JB cures. I may have to do a little bending and trimming on the rears, but shouldn't have any problems getting the incidence right on the money.

Chuck

SoCalSal

My Feedback: (16)

I don't have any photos yet. But what I plane to do is just drill a small hole on that bracket you sent me a photo of yesterday. Do it on the in-board end of course and then just slip the cable through there and put a crimp fitting on it. That way when you remove the wing panels the cables don't go anywhere, they stay wih the wing. But remember this.....Put a piece of tape on the turnbuckel on the other end during transport or you WILL loose the little eye bolt that screws into it.......YES YOU MOST CERTAINLEY WILL at the time when you need it most

SoCalSal

My Feedback: (16)

I just thought of another way to do it that might help you with the movment problem, You could get a piece of brass or stainless tubing . Put it inot a vise or what ever and make it flat, then drill a hole in it to go where you may want to shim the strut eye and have the other end a small hole for the rigging wires. This way you can remove the wires as well. God I should have designed the space shuttle with ideas like that.

SoCalSal

My Feedback: (16)

Here are a couple of pics on how I mounted my cowl. You may have other ideas as you may not be useing the same type engine. I'm sure that others will come up with there own ideas.

chuck l

My Feedback: (17)

In case any of you are interested, I got to ride in a real Waco on Friday on the island of Kauai. The plane was built in 2002 by http://www.wacoclassic.com/ and the rides are offered through http://www.tropicalbiplanes.com/ . The engine is a Jacobs that was built in the 1940’s. The sight out the front of the plane is quite neat, once the tail lifts off, prior to that you can’t see anything but sky. Obviously, the pilot can see more as he turns from side to side since he his further back. Anyway, it was a great experience. I posted a bunch of pictures at http://www.lundyphotos.com/Waco%20Fl...Web/index.html that show a few detail shots around the airplane.

gerry52

I go take a look right now!

Two months later than I expected, I just pinpushed the side view drawing of the 1/4 scale Barth Waco on the wall. I'm really exited start building this plane. Start uploading photo's soon.

Grtz,

Gerry

executor

I have started the 1/4 project in july 2005, and on 01.04.2006 the damn thing flew[>:]... Some pictures:

BobH

My Feedback: (2)

Congratulations!! I'm sure it flew very well. A very nice looking plane!

gerry52

Boy that's real quick, hope my Waco will turn out as good looking as yours. Wich motor did you choose to power your Waco?

Soon, after upgrading myself with a digital cam, I'll show you my first steps.


Grtz,

Gerry

executor

ZDZ 80 RV. An 80 ccm, 8,2 HP gas engine. I have tried to calculate a moki radial, but it wont go under cowl. So it's a one cyl. engine, but it does a very good job. The exhaust was a tricky business, but at end, it came uot very well. Oh there is also a smoke system installed and flight comp. DPSI-TWIN. There IS a plenty of space to fill on board the WACO.

executor

Oh and one more thing Gerry... The spec says that upper wing can be freely adjustable within range of 0... -2,5° ang. I have mounted the upper wing with -1,5°angle and it does good job even at critical speeds (I'm guessing that for such a plane scale Reynolds is most forgiving ). The angle for tail rudder should be ca. +2,0° ang. (nose up). Of course, if one should need another flying characteristics, there are other angles for use..

Marko

gerry52

That's great help Marko, I wrote down your wing angle recommendations in the manual. Thanks! Did you mount the ZDZ directly on the plane’s firewall or did you made it a bit flexible to minimize the vibration of heavy one cylinder motors? (with rubbers and Tony Clarks hydromount for example)
Last Friday I visited, just like every year, Intermodelbau in Dortmund, Europe’s biggest modellers exhibition. Almost all R/C manufacturers show there newest items and during the exhibition a lot off stuff is being sold much cheaper. Oracover for example, the average price/meter in the Netherlands is about 9 euro. In Dortmund it’s 4,75 euro. So I bought 15 mtr of white Oratex for the Waco for about 60 euro. The red striping is going to be painted (sprayed) on the plane. Two component paint works very well on Oratex and it’s resistant to almost any fuel.

After visiting the exhibition, there’s more doubt as far as the motor concerns. My mind really isn’t made up yet. Haven’t looked any 5 cyl. radial yet, because I thought they are above my budget, but after the exhibition I think it must be possible. The Waco is an important project for me, so I’m willing to save some extra money for a motor that really puts a smile on my face. A real challenge for me, because I have no experience with that kind of powerplants. There are two demands in which I won’t compromise, it must fit under the cowl and it has to be as powerful as the plane’s construction can handle (there’s, even for a scale plane, no such thing as overpowered). Other important issue is an acceptable vibration level.
Then there’s also a “nice to have list�, number 1 item on that list is a two or more cylinder power source. Do you (or anyone else), assuming price doesn’t matter, have any suggestions meeting the above requirements?
I also like to install a smoke system, but again, I’m a first timer in choosing and installing a smoke system. Any suggestions or tips and hints are really welcome here.
Last question for now, you wrote you equipped your plane with a flight computer. What’s the purpose of a flight computer? It sounds a bit like unnecessary “bling�, but as you may guess, I like some “bling�, and I’m interested in some info about it.

A lot of other questions (what kind of servo’s/battery packs to use etc.), keeping me busy but I haven’t applied one drop of glue yet so that’s for later concern I guess.

Thank you being so helpful till now!


Grzt,

Gerry

gerry52

Ow ja. Lots of R/C pilots never heard of the Reynolds number. On our flying site a lot of people says they can precisely explain the definition of this parameter, but at the end only one or two guys are really understand the Reynolds number and are capable to explain it. Keeping the large number of well flying model planes in mind, knowledge of the Reynolds number isn't that important for recreational flying and building model planes.

Grtz,

Gerry

chuck l

My Feedback: (17)

Marko,
Thanks for posting the pictures. I have cap stripping left to do on one wing panel, then I want to assemble the plane and set the incidences. I do have some questions if you don't mind answering them.

How well did the plane fly with the engine, I'm using a Zenoah G62?
Take off easy, land easy?
What size servos did you use on the various control surfaces?
Can you post a picture of how you did the flying wire attachments to the wings and fuselage?
Can you post a picture of how you finished around the tail wheel?

Chuck

executor

O.K. guys... some answers:


1. Engine is mounted directly on firewall. I have tried to use some compensators, but from my experience direct mounting can work out better with compact fuselage construction (and WACO is one of them). Of course, firewall is modified (greater thickness) with another wooden plate (original seems to fragile to me), then both sides are laminated with thin glass wool and epoxy. I have not chosen hydromount, because i've needed some extra space for ignition chip, ignition battery and a smoke system pump. My theory is that everything that belongs to engine electric support, should stay far ahead from receavers, aerials, ...

2. Oratex will do a great job. I have used transparent one and then painted with 2-K lack.

3. Radial engine was my wish too . But i couldn't find any suitable petrol engine that would go under cowl. Recently I've seen a new MOKI 150 ccm radial and perhaps this model would suit everyone needs. Other possibility was to use a classic methanol radial engine, but since i'm more petrol lover, i have abandoned the idea. If you can mount a radial, the plane would look as good as real one . Other possibility is use of boxer engine. But with need of a HP in reserve, engine should have at least 7-8 HP, that means ca. 70-80 ccm boxer. Boxer works fine, but i didn't want to cut sides of my cowl to make some room for spark plugs. One cyl. engine was a good compromise to me.

4. For smoke system, i've chosen a Slimline Show Time Pro. The battery is integrated and a pump el. motor is speed regulated. But an ordinary pump will do a job just fine. My oil tank has 0,5 l vol. I would suggest, that tail surfases that are open (tail wheel section, rudder/tail wings joint section, ....) should be protected with thin layer of transparent lack or better with epoxy. Oil fumes from smoker are condensing quickly and they can damage wooden sections on tail.

5. Flight computer.... sounds so Sci-fi heh ... Purpose was to have a central operating system for independed servo supply, independed servo control (pulse modulation check), double battery supply and duble receiver control. I have always wanted to eliminate a possible errors from installed equipement, so with this set of control there is only one mistakable factor. You've got it right. Me!!!

6. As for installed equipement:

Servos: Ailerons: 2 x Hitec 5745MG digital (yes i know, too strong [>:])

Rudder: 1 x Hitec 5645MG digital, 1 x Hitec HS 925MG for tail wheel

Tail wings: 2 x Hitec 5645MG digital

Throttle and Kill switch: 1 x Hitec HS 925MG each

CPU: Emcotec DPSI-TWIN, DPSI-ICE

Power supply: 2 x Longgo LiPo 3300 mAh Safe

Recievers: 2 x Multiplex RX-9 Synth DS IPD

7. Reynolds... theory from my university: "The Reynolds number is the ratio of inertial forces to viscous forces and is used for determining whether a flow will be laminar or turbulent. It is the most important dimensionless number in fluid dynamics and provides a criterion for determining dynamic similitude. When two similar objects in perhaps different fluids with possibly different flowrates have similar fluid flow around them, they are said to be dynamically similar...."

But there is one little problem. Determination of number is more complex for outer flow (easy for tube flow theory) theory. And aircraft is an object of outer flow theory. Since a normal Re calculation depends strictly from fluid velocity (aircraft section speed), characteristic dimension, fluid density and dynamic fluid viscosity, calculation should be easy for elementary objects; not aircraft !!! Normaly we use also Euler number for macroscopic calculation (plus Pr number in model scaling), sufficient calculation comes across only with use of microscopic observation of laminar flow (with Navier-Stokes) or better observation of laminar/turbulent border.

All that is just fine when one calculates a stationary flow status. As for aircraft or better aerobatic aircraft models (NON stationary flow status), we use Re simply to determine approx. flying characteristics of an model plane from his big brother. That all depends from a aircraft scale (normally bigger is better; mostly but not always) and of course from right wing profile construction. Therefore the similarity with real aircraft can be achieved even at totaly different Re numbers, mostly with use of right wing profile.

There is a very good model aircraft aerodynamic theory in book Aerodynamik des Flugzeugs (Amazon, ...).


8. Flying with ZDZ80 came out just fine. It has some HP in reserve (so i used 24-12 prop for low turn speeds, but better prop efficiency). Take off is very smooth, due to a very efficient rudder. Landings are not so tricky, but i had a few "bums-a-daisy" at first[:'(]. Plane is very inert and main springs are doing their job...

You will find some pictures and a first flying movies at http://s54.yousendit.com/d.aspx?id=3...N1N52Q3K5HLWV5 (max. 25 downloads)
sorry, some pics are bad...


I hope that you guys will be satisfied with model as i am.


Marko

chuck l

My Feedback: (17)

Marko,

Thanks very much for the pictures, they will come in very handy with the remainder of the construction of my Waco. You did an excellent job!

Chuck

gerry52

Marco,

You're really great help making up my mind about the Waco, thank you so much.

This Saturday my XTRA-2000 (2 x 2 mtr F3A plane) successfully had it’s maiden flight. 2 Beeps (clicks) of aileron trim and 4 beeps for the elevator was, sufficient to keep the plane in straight and level flight. After running about 15 tanks of fuel I’ll lean the mixture a bit, by then the OS 160FX has had it’s most important period of breaking in, after that, the real trimming of motor side- and down trust, wing and stab angle has to start. For all planes, but especially for a F3A plane, it’s well worth the time and effort.

Almost ready to start the Waco project, I bought a new workbench to accept larger planes. I installed 4 wheels to freely move the bench around, accessing both sides off the Waco will be easy now.

Keep up the good work, and thanks for the clear explanation regarding Reynolds an his number! The last time I had to deal with it, was at school, calculating valve openings for fluid streams. Too long ago now…




Grtz,

Gerry

executor

After last week exhaust problems, smoker began to operate as it should . I have increased oil flow and directed it directly to inner exhaust tube exit. It works great. With normal aerobatic figures (loops, rolls, cuban 8, rolling turns,...) the flow of oil fumes does not interact with plane surfaces. Unfortunately, with stall spins, hammerheads, .., plane goes directly in its oil fumes which makes a very thin but unwanted layer of condensed oil through all the plane surface. Fortunately 2K colour holds. My recommendation is to make a very efficient covers for all open plane parts (cockpit, tail wheel opening, rudder cover, ...) or better don't do those type of aerobatic figures with smoker [:@]

short movies: http://s53.yousendit.com/d.aspx?id=3...P01Z74ZH8PGI6G