KidEpoxy

Is there a structural reason to use the balsa on the Fuze Top & Turtledeck? Could a Flanksteak Flyer get by with more tray foam for them curved decks with adequate PU glue? I'm really dieing to keep it to the trays, if thats possible.

D Bronk

YA` still got my intrest Z.Z !! D.B.

ZoomZoom-RCU

Thanks D Bronk!, and yes Kid Epoxy, it would be just as easy to use the foam tray stock, I just used the balsa cause I had it lying around and wanted to get rid of it. Its not really that much different.

ZZ.

ZoomZoom-RCU

[8D] Ok, the next bunch are as follows: The first is a bad image of the bent side panels and if you look closely through the haze, you can see how I scored it on the inside to achive a somewhat smooth curvature. The next is a rally bad thru shot of the fuse from which you can barely make out the back side of the fuel tank peeking out through the space between its platform and the top former. Next is a shot of the tail assembly. The next few are of the rear stabilizer attachment as well as the bottom wing attachment. Of note here is how they are attached. The horizontal stab is attached flat along the back of the fuse, which should be cut straight. You can effectively use this as a measurement basis for your centerline of line of thrust, and even though the actual line of thrust is beneath it about halfway down the fuselage, it should still run exactly parralell to it. So you can effectivelu use it as your base line from which all others are drawn. So, the horizontal stabshould be dead on this line. As you can see in one of the shots, I use a small level to find my wing incidences. For this small tripe, simply prop the fuselage up so this reference line is level (bubble in center) then to find the correct wing inidences I simply set the wing in place, trim it so the bubble is just a fraction, about 1/4 out of center towards the leading edge, then lock it there with glue. This gives a slight positive incidence on the wings. Oh and I think the last pic is of my wing press. This will work with either ebtirely meat tray, or foam cut wings. You simply cut a small "V" notch down the center, run some glue in it, and prop the ends up with whatever is at hand to lock in the right dihedral. I used some scrap sticks, and then pressed it all with some cans to hold it till dry.

ZoomZoom-RCU

Dont worry, I know I've jumped ahead abit in attaching the bottom wing, but I'm getting to their covering and finishing method next. As you'll note in the last pic I posted, there is the one uncovered wing getting its dihedral done, and the two covered one's in the rear. Thats where were heading next!

Regards. ZZ.

ZoomZoom-RCU

Right oh, the wingy bits. Afetr you have your wingo's cut out of blue foam, orrrr glued together from meat tray stock, you've got to cover them. I use recycled office paper. Yup, you heard me right. the first pic below is of the wings after sanding and before trimming to the classic fokker shape, the second is after this trimming. Just draw out the outline and cut it with a razor knife. Thenext pic is of the three getting their dihedrals set and glued in a simple press. I used paint stirrers to set my dihedral angle. The next is of the wing covering, recycled office paper, cut to the shape of the wing. Doone side at a time. I usually do the bottom first and make the paper come out to the very edge, then when I do the wing tops I make them a bit large chord wise and lap them over the bottom. The next pic is of the glue being spread on the wing. A little glue and some water to spread it around. Dip the paper in water a second or to for it to soften a bit before applying. The next shot is after application of the paper to 1/2 of the wing. Smooth it down with your hand, wipe away excess water and smooth out air bubbles. The last shot is a rather belated shot of the fuel tank positioning and the "hole cut mark" for the plumbing through the firewall. When I cover these wings, the paper adds an incrdible amount of strength. Keep your dihedral press in place and after you do one side at a time, first bottom then top, place the wing back in the press to dry to shape. This is when you can add some washout at the wingtips by slippinf some 1/8 inch wood stock or whatever under the wing tips on the back sides. Press the whole wing down with a light weight, paint cans etc, and let dry. The paper will permanently dry the shape into the wing! If this isn't clear let me know I will explain further.

PS. On the wing ends, simply cut the top covering so it sticks out beyond the wing tips. Cut it chord wise every 1/2 inch then fold over and glue so it wraps around the tip smoothly. I may need to draw a simple picutre for this if it isn't clear, but it works great.

ZZ.

ZoomZoom-RCU

Sorry, pics didn't go through, here they come:

ZoomZoom-RCU

MORE:

ZoomZoom-RCU

Last 'uns

KidEpoxy

Do you put any overlap of the paper covering the winges at the root area? Cause IIR there is no spar, and I figured the paper would have to exoskelleton the wing, and the root area looked weaker with no overlap. Or am I just being paranoid, it's plenty strong theway it is.

ZoomZoom-RCU

Yes, I assume you mean mid wing center where the groove for the dihedral is cut chord wise. Yes, an overlap here of roughly 1/8th to 1/4 inch is fine. I guess you could do more but in my opinion it just adds weight and tends to look funny. But your right, this finish tightens down like a drum head when it dries and creates an exoskeleton thats very tough. I couldn't have put it better myself.

ZZ.

KidEpoxy

would it be worth the slight effort to get a light grade copy paper, rather than 20# copy paper get some lighter "cheaper" office paper... you know, the stuff that always jams the printer.

Would the slight weight savings be worth the slight effort, less weight in paper & less Elmers-water soaked up.

ZoomZoom-RCU

I don't see why not. I'd like to see what weight savings you gain! After all your just gonna dope the paper with water based poly, and then paint over it, so I don't see any reason this substitution shouldn't work, look the same, and maybe even be better/lighter!?

ZZ.

ZoomZoom-RCU

[8D] Wow, Well I'm back finaly. Went on a bit of a vacaccionne'. So I'll try to pick up where I left off.

The next few are as follows: A frontal view with a slightly blurred image of the engine mounting. I later altered this so the engine tilts downward and out of the cowl for better cooling, and it does kinda look like part of a radial! The next few pics is the 2nd wing being glued and weights used to press it into its saddle. I simply measured the wing width chordwise, and dremel cut the saddle out of the front turtle deck. Once you seat it, use the same method of finding a slightly positive incidence with a bubble level or whatever device you prefer, then glue in place and press the wing to be sure it stays put till dry. I cut, as you can see in one of these pics, little foam spacers to be sure the wing tips are the same distance from the lower wing on each side. Each wing on the tripe is staggered forward as they ascend approx 1/2" inch forward of the lower one. Sorta like stairs. And the last pic is of me grinding the edge of the fairings down so they meet the fuse more fluidly.

ZZ

foxxieboy99

thats cool buddy .........build another

ZoomZoom-RCU

[8D] Thanks FB99. The next three pics are of the blanks used to create the wheels and the cowl mold. Basicly each of these blanks have a dowel (or pencil) glued to the center and they are then turned in a drill, using coarse sanpaper as the "lathe cutting tool". As you can see in the pics, the three large discs are for the cowl, and are stuck together with spray adhesive. The smaller two discs are the wheels. This is all from 1/2 inch blue foam.

Wayne C

Okay, at the risk of revealing my ignorance, what kind of glue do you use to connect the foam parts together and do you use the same stuff to connect the foam to the wood?

I have a T.D. powered P-40 that needs recovering and a new wing. I'm really considering making my own foam wing.

ZoomZoom-RCU

[8D]Wayne, there are no ignorant questions................well, maybe there are, but yours isn't one of them! As far as gluing foam to foam for say making the cowl blank, I use 3M super 77 spray adhesive. This bonds blue foam to blue foam pretty well for wing core or other blank construction. As far as the rest of the tray foam and wood bonding goes, I use polyeurethane glue, the kind that foams up when it cures. It works REALLY well. And creates a super bond. I hope you decide to give the wing a try. Its much easier than you would think. After you do one like this, you'll never go back to playing "fiddle- sticks" with balsa again. Are you going to hot wire it or some other method?

ZZ.

ZoomZoom-RCU

[8D]Oh Wayne, one more thing. I use regular old wood glue to skin the wings with, ie, a wet coat of slightly thinned wood glue over the wing surface, then lay the damp paper over it like a decal. DONT USE POLY GLUE for this cause it'll foam up and leave a bumpy mess on your wing! Sorry for any confusion. Just wanted to avert a potential mess!

ZZ.

ZoomZoom-RCU

[8D] These next pics are of the turning process for the cowl blank. Just stick the pencil you glued in the center of the foam blank into your electric drill chuck. I use a piece of particularly coarse sandpaper for the cutting tool. Its fairly simple to get the shape you need.

ZZ.

Wayne C

Z.Z. Thanks for the info on the glue. Mandatory overtime and helping my son with a robot project have kept me busy lately. While I am hoping to do some balsa projects in the future, I'm also wanting to explore foam building. I priced some blue foam at a local building supply store the other day. Seems very economical. I'm very interested in the foam bow process. Bow no problem. Guitar string no problem. Power supply -- problem. Any suggestions on getting or making one?

ZoomZoom-RCU

[8D] I hear ya Wayne. I've been quite busy myself, so I haven't been keeping this thread updated as often as I should. But it will get done. I guess I've been having too much fun flying the little thing instead of banging away at the keyboard! As far as your question about the power source for the foam bow. There are two things that I have personally used to power it, but if anyone else following this post has any other recommendations feel free to chime in, as there are many options for this. What I am using now is an old electric train transfomer. This particular one has multiple outs in different voltages. I use the 18Volt out and simply run a wire from each side of the "out plug" to each end of the foam bow. If you use thin wire you will get a longer cut before the overload switch goes off. This was a high end transformer, so it has an overload switch. I dont know if the low end ones do, but its nice cause it keeps it from eventually frying itself. Another thing I have used was a charger "wall wart" for a regular RC plane starter battery. You know the kind you plug in and it has two alligator clips to attach to your battery terminals. Instead you just attach them to either end of the cutting wire. This eventually did stop working after extended use. As I mentioned before, It didn't have an overload cuttoff so thats probably why. With the overload transformer you cut a few inches then it stops, you switch off the transformer for about 20 secs, hit on again, cut a few more inches etc. Its annoying, but it hasn't fried yet!! I'll bet the cheapo's dont have this so you can burn an entire wing in one swipe. If they eventually fry, hey they're cheap anyway! Hope this helps. I'm sure there are many other options, and if anyone wants to throw them out, please enlighten us! I have also seen diagrams to build your own on line, but this is a cheap easy effective way to get started quickly, and you gotta love that!

ZZ.

Andrew

Some folks use a standard light dimmer, some use a Variac. We have built a couple of [link=http://nsrca.org/technical/tip_tricks/foam_cutter/foam_cutting_power_supply.htm]these[/link] for use in our robotics lab, but they are a little insensitive to heat control, although work very well.

You can check [link=http://www.uoguelph.ca/~antoon/circ/circuits.htm]Tony van Roon's site [/link] -- there are about 10 cutters listed there, plus a lot of nice simple circuits.

I've got parts coming in to build a DC PWM power supply, but I don't know how it will perform until I get it built -- the safety advantage is that it will will have a DC final rather than AC and hopefully allow fine tuning of wire temp.

ZoomZoom-RCU

[8D]Ok, so here are some more pics of the cowl making process. As I indicated before, you can turn the cowl blank from blue foam in the chuck of your drill with a piece of coarse sanpaper as the cutting tool. After its roughly where you want it, smooth it in the drill with a piece of fine sandpaper. After doing all of this I coated it twice with two applications of wood glue to the exterior to seal it. Then after its dry and hard, brush on a light coat of vaseline and then cover it with a layer of Bondo as in pic one. I used a clamp to hold it upright till the bondo dries. After this is hardened, pry out the foam blank and you have a lovely female mold. You may want to hit the inside of this with some light sandpaper as well to remove any minute ridges left from the Vaseline. Now you can make your cowl. As seen in the next two pics, coat the inside of the mold with a light coat of vaseline, and lay in a few layers of damp paper strips and glue in between layers. I usually do Light coat of glue/ paper /glue/ paper/glue to finish. Allow it to dry a few days and when it pops out you've got your cowl. Then you can trim and sand it, paint....etc. In the pics you can see along with the laid up cowl, the wheel fairing after covering being dried, as well as the top access hatch which has been covered and is drying.


ZZ.

ZoomZoom-RCU

[8D]The next three show the way I ran the push rod tubes through the fuselage. The servos will be located under the fuel tank, with just enough of their tops showing so you can adjust them from above through the access hatch. I used left over golden rod push rods for the tubes, and inside these I run small guage piano wire to do the actual "work" on the control surfaces. A criss cross design with these tends to lend more "push" strength it seems. Also in the first pic you can see how the outer wing struts are inserted. These are made from lite ply, and slits are simply cut in the wings in the appropriate areas, and the strut is slid down into place through these slits, then glued in. For the DR1, the struts are angled forward from the bottom wing to the top. Simply look at the model from the side and consult a three view and its not difficult to approximate this angle.

ZZ.