other types of building techniques

[woundedbear]

Hello everyone!
I have built, two 500 series, two 400 series, and one 300 series guillow's kits. When I was very young I built four of the 900 series (only got 1 of those to fly).
I discovered the De Havilland Hornet and Sea Hornet, about three years ago. I had never seen one until I saw a Classic Airframes 1/48 scale kit on ebay. I bought that kit, and went of the internet to learn all I could about the airplane. I learned that it became operational too late to have been used during WWII, and the sad news that there isn't a single one left in the whole world. It was England's most famous test pilot (Eric Brown) favorite aircraft, so it must have been quite a fun airplane to fly. While I was researching the Dh.103 Hornet, I learned about a small outfit in the UK, that were going to produce a balsa wood model of the twin engined Hornet. The company was called the Blue Bottle Squadron, and it was going to be in 1/16th scale. The kit was going to be a laser cut,rubber powered kit that could be converted to a simple electric RC. The BBS company's owners had some kind of tragedies in their personal lives, and the company went under before their Dh.103 Hornet kits were put into production. Needless to say, I was disappointed, however I looking on another forum (sorry Guillows) and found that an American designer had done all of the developmental work for the BBS Dh.103 Hornet kit. I got in touch with him and he has a supplier that does the laser cutting and vacuum forming for the model airplane plans he sells. On the other forum(sorry again Guillow's) They have a build thread that shows the BBS Dh.103 Hornet kit being built as a test shot. The kit used a building technique that I have never done,"I think it's called the box type build", Has anyone on this forum ever done that type of build? I am not sure, but I think the Guillow's Fly Boy #4401 is built this way. I know some of you have built other Guillow's kits that use this type of building technique, and have built other brands that use other build techniques. I have not had any experience building anything, but the Guillow's center keel type of fuselage and half former building technique. Any advice would be greatly appreciated.

[tom arnold]

The box fuselage technique has actually been around since the 1920's and 30's and is a very common method along with the half-shell former method that Guillows uses. Both have their advantages and disadvantages and both have their champions. The biggest disadvantage to the box method is to make sure that the box is straight and true and that both sides are identical and there are all sorts of little building techniques guys use to accomplish that. It also can be a lot lighter than the half former method IF you don't get sloppy with gluing on the the quarter formers to fill out the fuselage. Here's John Ernt's website that shows his method of making sure his box fuselages are straight and true. The big key is to have some type of right angle blocks to prop the sides up at 90 degrees during gluing. The second key is to cut the top and bottom braces to the EXACT length before the gluing. https://www.flickr.com/photos/42494595@N06/

[woundedbear]

Thank you tom arnold, for your reply! Cool website. I was very impressed with the flight of the Biplane in the video. The way the guy had his rubber powered model plane trimmed out, it flew for such a long time, but stayed within the field. If there had just have been a smoother place for it to land, that flight would have been perfect! Well keep the answers coming guys, and model on Dudes!

[Chris A.]

Actually, Guillows used the box method into the 1960's on some of their kits. I built a Guillows 18" wingspan Hurricane I that came out very well and very light. I've yet to build the Guillows box method Spitfire II of the same size. The Hurricane kit needed modification, namely more dihedral, to make it a good flyer with a larger prop and an adjustable noseblock. Partially die cut, you had to do the notching of formers and ribs. I ended up with ery light construction compared to the current Guillow's keel and former method. I have an early Comet kit and plans for a P51A that uses the box and former method. The P 51A, lends itself well to this method as most of the shape aft of the wing leading edge is made up of straight lines. Only the engine cowling top and bottom are curved in outline. For actual scale flying models I prefer the B & F method as it builds so light. But careful wood selection and accurate construction is critical for a successful model. For example, I build the first side, cutting pieces as accurately as possible, pin, glue and let it dry, then built the second side of the box directly over the first with wax paper in between and try to use the same pin holes. I use Elmers rather than super glue as Elmers tends to wet the wood and then dry with a bit of flex still left. You'll need a lot of pins. When dry, I check both sides for absence of any twists or flex differences, then double glue all joints and let it dry again. If yours comes out twisted or just not right according to the plan, don't try to fix it, just start over. Tedious, but when accurately done, it is very light and strong, especially aft of the CG. When trimming the Hurricane for a good glide, I weighted the nose with clay and found I needed only a small split shot that exceeded the prop weight by just a little. In still air it made a nice glider. I had covered it in white with Russian winter markings rather than camouflage chalking or painting to keep it even lighter. Under power it didn't fly well with a large prop as the tail surfaces were almost scale so I had to go back to a smaller prop. The old Guillows kit had no decals and no canopy, just two red plastic wheels, a small prop, one rubber loop and a red plastic nose block. Back when new? $.69 + NY tax.

[Bill Gaylord]

Not as light as box construction, but you can construct your own formers in box style, eliminating the weak cross-grain portion of conventional formers. By taking advantage of the grain strength, you can use really light wood, and then cut away a good bit more after constructing the basic keeled fuselage. I did this with a 19.5" DH106 Comet EDF r/c model at 80 grams AUW.

[Chris A.]

Bill, I looked at your pictures a bit closer. Is that an electric fan mounted to exhaust where the Jetex would have been mounted? Clever solution, I hope it works well for you. The DH 106 is interesting in that it has a very clean shape with generous wing area. I was thinking RC slope glider.

[davidchoate]

The "box" type built up model is easy to learn, and build. I practiced on some cheap "Walnut scale" Dumas kits. The hardest thing to get used to is the fragility of the thing until the stringers ,and etc. are all together, but if You have patience, and dont mind replacing constantly breaking stringers, You will be that much the wiser. I now will incorporate the "box method into Guillows builds. Say if I want to turn My c-47 display kit to RC. I may use the "Box" to build the nacelles, and eliminate the plastic. It's really a good way to start a scratch build, and all the worst is just the beginning part when it is time to line up the very weak and shifty four walls from "Racking". I think I had to do 3 attempts on My 1st model of that design before I got the hang of it.

[davidchoate]

Was'nt the Plane Bill paosted the one that had prtoblems with the enginges causing Catastrophic Wing Failure because they were actually in the airfoil of the Wing? I think I saw a show on that once, but anyway 80grams? AUW Bill? And It flew? Oh, and by the way. It's not againsty the rules to show modifications on Guillows forum that are taken from other designers. I just don't think You can do a WHOLE THREAD ON ANOTHER COMPANIES PRODUCT. Oh I found the photo of My 2nd build that was a 500Me109 RC, but never flew, but won 2nd place in a Hobby Town contest, and beat the super detailed Plastic Planes because of it's ability to possibly Fly. The Plane no longer exists. A little Girl Destroyed it.

[David Lewis]

davidchoate wrote: "Wasn't the plane Bill posted the one that had problems with the engines causing catastrophic wing failure because they were actually in the airfoil of the wing?"

I think the dH Comet's problem was metal fatigue originating at a corner of the celestial navigator's window near the top of the fuselage. Although the aluminum alloy skin was strong enough to resist steady loads, when the fuselage went through many pressurization cycles, the repeated expansion and contraction fatigued the metal.

The airliner where the engines caused wing failure was the Lockheed Electra. The wing's torsional rigidity was inadequate when the props went into whirl mode caused by gyroscopic precession.

[woundedbear]

Wow you guys are way over my head... I use to get into trouble at school, the teacher would be going on about math, and how important it was. Then she would catch me designing the latest fighter plane I was hard at working on...She just couldn't see that I was working on the world's newest front line fighter design. What was her problem anyway? Couldn't she see I couldn' t weight on her and all of those numbers I know what a fighter plane suppose to look like! Airplanes were easy math was hard Should have learned that math

[Bill Gaylord]

Bill, I looked at your pictures a bit closer. Is that an electric fan mounted to exhaust where the Jetex would have been mounted? Clever solution, I hope it works well for you. The DH 106 is interesting in that it has a very clean shape with generous wing area. I was thinking RC slope glider.

The fan has a duct cover, routing the exhaust through the actual scale nacelle outlets. It's my 3rd build of an EDF Comet, making this the cleanest yet, in terms of ducting.

[woundedbear]

About my last reply on this thread,"I was very tired when I posted it", but it brought up something . I had almost forgot. So I am going to start a new thread here on the Guillow's Model Builders Forum, I think it will be fun! I hope everyone contributes , it will also be a sort of pole, just to see how many of us stared think about airplanes at a very early age , and got into model building as a result.

[davidchoate]

Do you remember the wing area of the Spit Bill?