Does anyone recognize this wing?

Roddie, why not finish the Voodoo? A great part of the construction is done. If you want the modifications sheet that Carl Goldberg issued later on, just PM me.

Lieven

When Riley made the Voodoo, it underwent changes for manufacturing purposes. This was one of them. Goldberg and all the competition would redesign the kits to fit using stock width balsa and fit into the boxes they had. The Voodoo had a wider span according to Riley. While I toyed with offsetting the fuse and making wing panels shorter on the inboard side, the planes fly much better when the panels are symmetrical. It also allows for one to triangulate from tip to tail and vice versa when building allowing for the thrust line to be properly squared to the wing. I've witnessed more than one Voodoo built incorrectly due to the builder either building the wing upside down or not paying attention to the dado's on the leading edge having different spacing. Old woodie flying wings like the Voodoo have a tendency to get real out of control initially. The offset wing panels could be a contributing factor until the plane gets up to speed. Having a close coupled elevator on this plane also promotes the over controlling responses. This is why the long boom was a better point and shoot plane due to now being able to control it. However, the longer booms also slow down it's turning radius. Roddie, that plane is very close to being finished and it certainly would be neat to see it in action. Ken

Roddie, let me just explain a few things in regards to finishes. While many of these planes are "Old school" they don't need to be built in the same regards. In one of my recent posts I mentioned torsional strength. Many of the old combat planes absolutely needed silk or heavy silkspan with high shrink dope. High aspect ratio wings like the Whipsaw will twist under load. When these types of models get covered with conventional covering, the end result is a plane that immediately will fly tip high almost flying across the circle and then back out on the lines again. To circumvent this problem many have covered with 00 silkspan and then iron on covering over that. I don't care for that but what I do like is Phil Cartier's SLC (Super light covering) this covering is cellophane like but light somewhat like Mylar but it has adhesive on the back like Monokote. This covering also is chemically treated to accept ANY paint with a little Scotchbrite prep. The Voodoo however is a very simple wing design. The Voodoo will fly very fast in level flight but speed will QUICKLY kill off once the plane is put into a maneuver. The solution, set up the controls fairly slow, keep the cg right on . This is somewhat tough to do based on so many engine choices and the Fox .35 was one of them. While not my choice for this plane, I use a G-21-.35 Supertigre on bladder pressure. This is a heavy engine over the Fox.

The bottom line is, you don't need a sprayer as brushing dope can be just as rewarding and I can send you photos of brushed dope jobs that you wouldn't believe was done with a brush. I got real good at doing at. I personally wouldn't even consider silk or silkspan on a combat plane. They have too short of a lifespan and when you make them that pretty you just won't fly them like they're meant to be flown. Landing these will instantaneously tear holes in silk or silkspan due to weeds and small sticks. Why waste time on something that is going to get damaged? I cover in Monokote and this allows for easy wing tweaks. I use a 12 v inverter off of my car battery and a Monokote iron which allows for quick field adjustments if the plane is flying tip high or low.

The main thing with a Voodoo that typically isn't done. Two 3/16" dowels need to be drilled through the engine bearers from top into the bottom one through the vertical grain 1/2" balsa to lock the beams together and tie the motor crutch correctly into the wing. Even a Fox .35 can rip the nose off if this isn't done. Another MAJOR factor in the Voodoo construction that is always overlooked until disaster strikes. Goldberg used 2 metal L shaped hinge pins for the elevator. That by far was probably more responsible for the destruction of most Voodoo's than the actual models flown in combat. Use ONE single piece of 1/16" music wire inserted through the booms and then bend the L bend returns into the elevator. Fiberglass cloth over the wire and you now have a properly constructed elevator. This also adds a slight bit of needed tail weight. Ken

Here's my take on some of the issues you mentioned. Just build it. Even if something did happen to this plane, the only difficult part to obtain is the leading edge. At this point, it would be simple enough to fix it with some epoxy and lightweight glass. The probability of the leading edge breaking is more than likely not going to happen.

1. I would move the leadouts as suggested. You've probably read my posts on how crazy these can get on launch. This will resolve some of those issues by swinging the leadouts to the rear. It will also sacrifice some speed. All in all it's a good improvement and I recommend it. This will also require you to file out some rib material to allow for the added sweep.

I'm adding this in here due to a mistake I used to make early on with this plane. Sheeting for these planes over the bellcrank and tank area were determined by how many pieces Goldberg could use from a 3"x36" sheet. The idea was to silk or silkspan the model FIRST, then glue on the booms. I make the sheeting 1/2" wider to allow better contact for iron on covering. MAKE 100% sure your booms are properly lined up and directly over the underlying 1/8" #3 ribs. The forces on the elevator can create such force it can punch the booms through the sheeting resulting in a instant failure. I've even added scrap balsa to the sides of the underlying ribs for better support and glue area.

2. I would install tip weight on the leading edge nestled directly behind it in the outboard right corner at the intersection where the leading edge meets the wing tip. Wrap with thread or glass cloth. These weights can come unglued and will fly out of the wing. I've been hit with them and it hurts.

3. The cg for this plane is about 1 5/8" from the leading edge approx 1/4 of the first hole spacing on the #1 rib. If your plane comes out tail heavy, taper the booms. You can't properly determine the cg until the contols are installed. DO NOT put any Z bends into the pushrod . The G forces on this rod will bend and it will mush out the controls.

4. As for your plywood, I would just use it, why buy more if you already have something. Probably not the best, no worse than what you would find in a kit. I prefer 5 ply birch, but at this stage, it won't make a difference. BE SURE TO BUSH the holes with brass 3/32" tubing and then use the 1/16" music wire for the hinge pin.

5. I would rate engine choice for this plane by your skill level. You wouldn't drive a Corvette to take your driver's test in, same thing applies here. A Fox .35 or a good Mccoy will fly the plane just fine and fast. If your insistent on running the Veco, it's going to take a bit of playing around to do so. Running crank pressure can be very troublesome if you haven't done it before. Engines are prone to flooding and runs can get all fouled up. The biggest mistake made is too large of a pressure hole in the tap. You don't need a lot of tank pressure for this too work properly and steadily.

6. Tank choice for me is bladder so I provide a tube in the wing. The tank depicted in the drawing is a standard wedge with it's pipes reconfigured. I tried to explain this early on in some of my prior tank postings. You DO NOT WANT the overflow pipe projecting out of the bottom of the wing. You will snap it clean off and this tank isn't removeable without cutting open the wing. SO unsolder and cap the hole and throw the overflow away. Re plumb the tubing bringing the feed pipe out on the bottom and hugging as close to the leading edge as possible. This will also keep your fuel line short to your engine. If you wanted to make a pressure tank like the picture shows, don't let the description scare you. All the pressure line is doing is a single piece of pipe into the tank and this can be anywhere. They just show it on the front and they explain how to solder a restrictor into the tubing. This is related to my above statement as to not having a large hole in your pressure nipple.
7. Fly it like you stole it. Ken

Hi Roddie glad to hear you are getting this sorted out for a great build and fly . Ron had told me some time back when I was into the shoestring (classic) that needs a lot of work ....to reglue the joints that were previsely glued , I am sure you know this but didn't here it mentioned , he suggested sig cement witch I got some of ....hope it don't dry up before I get back to it   will probably use it on another model before then I hope     anyway just my  happy building ill be watching for progress report..Getback   

Roddie,

I would like to add a point nr 8 to Ken's list: Turn that trailing edge into a box section. Just glue rectangular vertical pieces of balsa between each rib against both forward edges of the strips that form the trailing edge. It will add strength to your wing and will prevent twisting.

Lieven