Mike,

Jack up the tail of the plane until it sits level. Tie a nut onto a piece of string and drape it over the leading edge of the top wing, and allow the nut to nearly touch the table surface. Now tie a nut to the other end of the string and drape it over the trailing edge of both wings, allowing it to nearly touch the table. What is the distance on the table between these 2 nuts? Plan on balancing the Waco at about 28 to 30% of the Mean Average Chord, which is the measurement that you made.

Bill, Waco Brother #1

I'll do that when I get home Bill, thanks!

Thanks Stick, I will try that also. Now just to clear up one point the measurement between the 2 nuts is used from the front of the plane to a spot on the wing?

I wish I was at home getting ready to maiden mine but that will have to wait. I do have a question for everyone. I haven't heard mention of anyone using an opti-kill type ignition switch. I have one installed in mine. Got it from Valley View RC. I have the same set-up on my Sun Dancer. Had my throttle stick on the Sun Dancer at about 3/4 throttle and was able to shut it down with a flick of a switch. How many are using them? ACF BTW I am using the DL-30.

No, the distance between the 2 nuts becomes the mean average chord. if the measurement between the 2 nuts is 16.75 inches, then take that measurement and divide by the percentage that you want. In this instance, 16.75/28%=4.69. Therefore the correct balance point would be 4.69 inches back from the leading edge of the top wing. Measure yours and see exactly where it should be. Since Dave Platt did the first of the Waco YMF kits the balance point has been stated at up to 40% of the mean average chord. This causes the plane to fly very tail heavy. A couple of years ago at Top Gun a beautiful YMF in 33% was severely damaged due to a dead stick, with a tail heavy condition. On rebalancing the model, it has turned into a *****cat. There are tons of horror stories about how hard the model is to fly. There is no need for this. A properly balanced Waco is a delight to fly. You just need to keep a little throttle in on landing approach.

Knowing the group at Great Planes as I do, I would seriously doubt that the balance point would be wrong. It does not hurt to check though.

Bill, Waco Brother #1

Thanks Stick that is some great info!! I have I Mustang that I might try it on. I am assuming that it will work on single wings also. ACF I don't use kill switchs. I set my throttle so that the manual trim om my 10x will close the butterfly all the way. I have to have at least half trim for it to even run. I am also planning on going to the new LIFE 2100 6.6 volt packs. JR requires no regulator. And one more thing that I did was to remove the choke butterfly and solder the little air hole closed so that it primes a little easier.

Here is what Bill was saying

Not that it is much of a difference but is 28 to 30 the standard because I have seen where some guys have said that 25% of the chord is the measurment that is used for CG!

The balance point will decide the pitch (speed) stability of the model. The limits are set by the maximum amount of elevator throw you can get and still flare for landing for the forward position, and the rear position is set by the pile of broken wreckage. Once-upon-a-time the magazines said "1/3 the way back" just about for everything, but the little tissue covered wood and wire f/f thingies always had big tailplanes and could bounce off most obsticles so it didn't matter. Big R/C scale models, with scale size tailplanes tend to be much closer to the full size where balances run between 18 to 25% for those airplanes that rely on the pilot for control. In the end you will decide where you like it most, I prefer 20 to 25% for my scale models, and use sufficient elevator throw to be able to stall the model at the slow end of the speed range, this leaves just enough for the flare. Set it up as Bill suggests, and mark a range of balance positions, say, 20 to 30%, balance at the forward end of your range for the initial flights, add elevator movement if you need, then trim the balance until you like it best, over the flying season.
Evan, WB #12.

I'll be interested to see if this comes out different than what is recommended.

Had the maiden flight today. Plane flew fairly well although the test pilot said the aileron throws were very sensitive, so will use more expo. The DLE 20 had plenty of power for this plane. Flew at half throttle. Loops were no problem at all from level flight. Seemed to be a bit nose heavy with no ballast added. Balanced at the recommended point the manual recommended. We had a minor mishap on landing resulting in a broken prop and some cosmetic damage. Will be easy to fix, just some scraped up covering. If the crosswind would have been less we would probably have been OK. Looking forward to the next flight.

Hellcat, That is a beautiful site!!!! I am so glad to hear you say the DLE 20 has plenty of power for this plane. I just got my muffler that Jtech made for the DLE 20 that resembles the AeroWorks Cessna 195 DLE 30 muffler. I will need to cut the pipes off some and otherwise it fits just as I want. As you can see, I have used a Hangar 9 engine mount as I really like how they work. I should be ready for a maiden a week from Sunday. Thanks for posting all the pictures!!!
Thanks,

I am ready for a maiden. Mine balanced at 5 1/4 with nothing extra added. Started the engine for the first time tonight. 3 flips, choke on till pop. Then 2 flips, till is started. adjusted idle so that with full down trim it shuts off. Will maiden Sunday! I don't remember when I have been as excited about a maiden!!! A couple of the guys that I regularly fly with have already asked what time I will be out! This is one beautiful plane!

Good luck on the maiden

Just a quick pic of my radial...just a bit more weathering and on to the next step

I just got my Jtech muffler in the mail Friday so I can finally finish mine. All I have left is fitting the cowl. I already put mu DLE 30 on a test stand at the field to run it in. I'll post flight pictures when I get her in the air, although the weather doesn't look good next week here in the land of OZ, 30mph winds.
This is a well thought out ARF.

lablover,

Dont forget the # 1 cylinder on radials is straight up at 12 oclock when installed.

P1 - is of NC 14081, a 1997 Waco Classic Aircraft YMF, ser # FS-009 with a Jacobs engine.
P2 - is of Nc 12428, a 1940 Waco QCF, ser # 3569, being restored, with a Continental engine.

Wind, Hard rain at times, solid overcast, I'm gettin' awful tired of this looooooong winter. Saturday, The radar shows a clearing, the WACO's all packed in the Caravan, drive around town shopping, take the wife to lunch, yada, yada, yada and still no break in the weather. Back home in time to see the sun peak out below the clouds on the horizon and it says, "Bye-Bye" !! [:@][:@] MM Sunday if it's clear, I ain't a goin to church, I'M GOIN FLYING ! [cussing at this point]

Great pics, I see I have more work to do. Any ideas what to use for that ring on the front?

lablover

It is the ignition loom that keeps the spark wires together as they come from the magnetos. And it protects them from engine heat as they pass between the cylinders. Some soft aluminum tubing from K & S about 1/8" – 3/16" OD polished up or painted with chrome paint. Just pull (stretch) it as you form it around an appropriate diameter object. You can simulate the welds with epoxy. Note the wire exit from the ring at the bottom of each cylinder of both engines.

P1 – Jacobs Engine
P2 – Continental Engine

Thank you Sir

I have spent way to much time with this fake engine but I think I will let it be as it is.. Someone will probably look at it from 10 foot away and not notice the little things anyway. I now have my muffler so can get the thing assembled and ready for a real flight. ( WACO STYLE!!!)
Thanks,

Looks really nice. Do you think you have enough of an opening for cooling?

Damn! We got a mormon skipping church and cussing! This is one nice airplane!

Cannonball, the dummy looks GREAT!

LOL Now that is funny! MM if you get a maiden tomorrow tell us it goes. I hope to and will post info if I do.

I think there's enough airflow room. I may drill some holes in the dummy cylinders on bottom 2. I'll figure it out so it won't overheat....




MM & Skillet,,,,let us know on the flying & take some pictures!!!!


Thanks for the comments on the dummy..