Thanks to the guys that answered my Prop Recommendation Thread. Here are a couple shots of the finished model. My brother built this and I basically recovered it and finished it off. I couldn't stand to have it just laying around. Pretty fancy for a combat ship I know, but the black covers some really bad stains in the old silkspan. I had 2 decal sheets from the old kit and decided to see if they would work without crumbling. Surpize suprize!! They did. So I'm just gonna play with it and maybe get my brother back in the circle.

I hear ya Steve, those were the greatest days of Combat.

Great looking Voodoo you have there.  I have an original voodoo kit I am building but the booms are half that length that came with the kit. Should I use these booms?  or make longer ones? I must have a later kit.  I also moved the front lead out tube closer to the tip brace in order to bring front lead out 1/2" to the rear from it's original location on the plans for better handling.  I am not sure what fuel tank yo use.  I was just going to make one and run a Super Tigre G21/35 Combat motor I have under pressure.  I seem to remember a bladder but don't know were to get one.  

I am getting back into control line after 37 years away from the circle.  I flew Combat and Rat race back in the day.  Skat Rat, Quickie Rat, using Torp RR .40, Super Tigre RR 29,  etc.   I even set a couple records back in the day flying Rat Race.  Anyway I dirges. So, Any comments on how to proceed with my Voodoo?  I am trying to remember but I know a lot has changed and would like to hear what I can do to make my plane better. I am looking forward to you suggestions.

Thank you

Steven Davenport

Hey Randy
Is that carbon Veil on the stunt plane?
I sure want to try that one day.
Hows it working out?

What plane is it?
looks nice.

Voodoo Tail Booms:

I flew many a VooDoo with the original short booms. No problems at all. Have at it and have fun!

Bob Heywood
Dayton, OH

I never did the Voo Doo long tail.
The other long tail airplanes I did were a lot better.

The longer moment helps and seemed to make smoother flying airplanes.
Moving the stab back helps balance with out adding as much weight.
The combination also requires less elevator movement and thus less drag.

Shortly after I stopped flying combat I did here comment from those who kept flying that the long tailed Voo Doo was a heck of a good flying airplane. A big improvement.


David

The first generation short booms wouldn't work with any engine.

The second edition had longer booms that were OK for engines like the ST 35C and other plain bearings.

But if you ran a ball bearing engine, you need (like Randy) to make them longer yet (or else carry a ton of tail weight.)

Replacing the short booms with long ones will also allow you to use a better quality plywood than what is provided in the kit. FWIW: The short boom kits were the early ones. I've flown both and prefer the longer booms. The one I had until recently had long booms, an  Enya .35 and metal suction tank. Plenty of performance for sport flying. 

Ok then, I am building longer booms.  This will be my first plane and first flight in 37 years.  I will post pics when done and maybe a video of the flight. Should be like ridding a bicycle. You never forget how I hope.  HEHE

I'd use the longer booms.

Hi Terrence,

Do you have pictures of the Howard's Nemisis II's?

Steven

I don't mean to hijack this thread, but...




There are several reasons that the Nemesis II was superior to the VooDoo.  Howard Rush designed the airplane when he was in High School in Overland Park, KS.  He took the NACA airfoil data from "Abbott and von Doenhoeff's 'Theory of Wing Sections'" (which was a compendium of the early NACA variable density wind tunnel tests) and modified the "4-digit" section data presented therein.  Howard and his flying buddies tried the 15% thick airfoil (from the book) which flew fast but didn't turn well, and the 18% thick airfoil (also from the book), which turned well but didn't fly very fast.  Then they "averaged" the coordinates and came up with a 16.5% thick airfoil.  Howard then "shifted" the point of maximum thickness from the standard 30% of the chord length to 25% of the chord.  THAT was the breakthrough.  .   Shifting the point of maximum thickness forward makes a LOT of difference in the maximum lift that a 4-digit symmetrical NACA airfoil can produce.  My later computer modeling yielded the info that placing the max thickness at 17.5% to 20% of the chord length produced the max lift.  Later AMA and F2D empirical data prove this out.

(Note: Howard tried an earlier design, inspired by the Big Iron and VooDoo type designs, which he called the "Atropos". ( one of the Greek fates, which "cuts the thread of life' cute name for a combat plane, huh?)  The Atropos used a NACA laminar flow 6-digit airfoil.  It was apparently a disaster and wouldn't turn worth a damn)

The longer tail booms do two things.  First, as noted, it reduced the need for "tail weight" to balance the newer, heavier engines and secondly, it increased the "maneuvering stability" of the model.  It became more "pointable" and more accurate.  In the early 1970's my flying partner and I tried a Nemesis II with 8" booms.  It turned out to be too much.  6" booms seemed to be the optimal for the Nemesis II.

When Howard was in school at Purdue, in the late 1960's, he met fellow Purdue Aeromodeler member Neal White.  Neal took the Nemesis II info and designed the Bosta (Portuguese for "crap").  The Bosta is for all intents and purposes an elliptical planform version of the Nemesis II.  It uses the same airfoil.  The idea was that according to aerodynamic "linear theory" an elliptical planform has less induced drag for the same amount of lift.  In other words, it wouldn't slow down as much in the turns.

In the early 1970's, when I was in High School in Kansas City, my flying partner and I met one of Howard's old flying buddies, H. Brooks Herndon.  Brooks gave us an early set of Nemesis II plans and also taught us some of the rudiments of aerodynamics.  We took that info and came up with the first "practical" tapered-wing,  foam wing combat plane, which we called the Shrika II.  The basic idea was the same as the Bosta, a tapered wing has less induced drag than a rectangular wing, and making it from foam, was more practical than cutting many different balsa ribs.  We campaigned the airplane around the Midwest successfully for several years.  When I was in college at KU, I CD'd a contest in Kansas City and Tom Zon (then from the LA area) came out to watch.  He saw our Shrika II and was impressed with the performance.  He asked for plans and cores so we went back to my dad's house and I taught Tom how to cut foam, gave him several sets of cores and a set of plans with the promise that he wouldn't give them to "Bozo's" who wouldn't build them right.  True to his word, Tom only gave the plans and cores to those who would build them correctly.  The airplane was a success in the SoCal combat arena.  

In 1975, Joe Kall won the Jr Nats championship with the airplane.

http://stunthanger.com/smf/index.php?action=dlattach;topic=13543.0;attach=46281;image   Picture #1

http://stunthanger.com/smf/index.php?action=dlattach;topic=13543.0;attach=46287;image   Picture #22

That's me on the far left of this 1975 Nats picture #37 holding the clipboard:
http://stunthanger.com/smf/index.php?action=dlattach;topic=13543.0;attach=46291;image

Later on, I stretched the Shrika II out to 48" switched to a single laminated tail boom and used the Eppler 475 airfoil instead of the original Nemesis II airfoil ( a BIG mistake).   I called it the "Bateleur" ( an African eagle) The airplane was a p.o.s.  It was only many years later that I discovered that it was the E 475 airfoil that was to blame and that it would have been a great airplane if I had used the Nemesis II airfoil.

Fortunately, even though I dropped out of Combat due to military service and raising a family, development of the concept continued in SoCal and Greg Hill and Pete Athens came up the the "ArrowPlane". There were other derivatives of the ArrowPlane concept, such as the "AllenPlane"/Bounty Hunter, etc.

So there you have it.  The Berryman "Big Iron" and the Wooten "VooDoo" type designs led to the Nemesis II which led to the Bosta, which led to the Shrika II and the Bateleur which inspired the McFadden "DreamSicle" and the "ArrowPlane" which in my opinion was the ultimate development of AMA combat.  And then AMA combat DIED... (except for the bi-annual Bladder Grabber in Seattle)

So now you know, "The rest of the story".

Howard:  If I'm wrong about any of this, please correct me.

Thanks Gary!
Thats more info than Howard ever let out!!
That is interesting on the design.
I came up with a very similar airplane in high school.
It started off with a redwood senior wing rib that the front was shortened and reshaped for using 3/8sq Le. resulting in about a 25% high point(max thickness).
The tail boom length was established by how long can they be from a 12in long sheet of plywood? as long as I can make them!!
The elevator was from a voo doo and the airplane was almost un-flyable being tail heavy, so the elevator was cut down in size until all that was left was a small elliptical shape.
My flying bud Tommy flew sneakers in combat tried it out once.
When he did a loop it would take one or 2 more loops for him to get it back to level!
This scientific design process is the same as Al Gore and Jerry Hansen use!!!


This brings up another subject.
After combat at the 75 Nats someone rode back to Alexandria with me so they could catch a flight out of the airport there.
Who ever it was had a set of .15 nemesis plans they were taking home with them.
Well--the left them in my car. Kind of understandable as I thought that the Opel was a race car and he probably needed to get out fast.
I still have their plans if anyone knows who it was!

Gary, I remember you now that I have seen picture #37 , but for the life of me I can not remember the blond#34
With her foot in your------
Something is wrong with my memory.

Steve---Long tail booms--long tail booms. the increase in moment arm leverage will overcome the longer polar moment and the balance will be much better.

If it has been that long since you flew need to practice not getting dizzy.
Spin in circles until you fall down--get up and do it again.
I try to do this often ,usually with a cat held tightly at arms length.
When you can set the cat down gently as you fall and the cat cant walk away your ready!
Tried it with our German Sheppard when she was a puppy, She is to big now, so is the wife and kids.
Cats work good.

My humor runs amuck tonight.

David

I just saw Gary's post.  The Nemesis history is pretty much right, but I finished the project after my family moved to Indiana in 1962 and I had access to a library with NACA reports and aero textbooks.  The Nemesis had four things that differed from most combat planes of the day: the airfoil, the long tail, the straight pushrod, and the aft leadout position.  Coincidently, Gary came through town last weekend.  We had a nice visit, and he showed me CFD data showing that the Nemesis I airfoil (0016.5 with the max thickness squished forward to 20% chord) was better than the Nemesis II's.  Now he tells me!  I did minimal testing at the time and thought that the 2 was a little faster.  Both had 5-inch tails at first.  Gary convinced me that longer was better.  I plan to fly Nemesis 2s at the 2010 Nats, though.

I think my best combat planes were the foam Rushpuppies I flew in both AMA and F2D from 1979 to 1989.  They had the Nemesis II airfoil.  When I made the 1990 F2D team, I had an aluminum mold made for the pretty-much-all-composite Snorts.  Before I committed to the mold, I was able to get a CFD comparison of the Nemesis II and Eppler 475 airfoils.  It said the 475 was better, so I used it for the Snort and Son of Snort.  Dirty Dan and, I think, Chuck Rudner used it, too.  Speaking of Chuck, as I remember, his Scalpel had a Nemesis II airfoil. 

The Arrowplane came from Steve Hills, a genius So. Cal. artist, who grew up in Lubbock with Pete Jaden, the Mearses, and such folk.    Phillip Granderson went to Hermosa Beach to hang out with Steve (which is really fun) and learn to build foam planes.   Phil, who is really smart (I hope he doesn't read this) and approaches things more scientifically than most, added more innovations.  The result was the Granderdog, with which PT got 3rd in the 1980 WC and won a bunch of stuff thereafter.  Mel Lyne is still winning Bladder Grabbers with them.