vertical grimmace

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This thread will tackle the construction of the Matney Zoomer from Matney models. www.matneymodels.com This airplane was designed for an event called "animal 500" which I am not familiar with other than what the website mentions about it.
My motive for building this plane is I like to go fast but mainly because I like to go faster than the other guy! I want this plane for our club races and I really liked the way it looks. We fly 3 classes of 2 pole pylon once or twice a year at our funfly's and this would fit in the 3rd unlimited\open class.
The Zoomer is offered in 3 differant configurations, a typical 12% 500 square in. hershey bar wing, a 15% full symmetrical hershey bar or a 12% tapered wing which has a longer span at about 60".
I went with the tapered wing. I like the way it looks and really like how these planforms fly.

vertical grimmace

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I do not have all of the material rounded up to fire through this build so hopefully you all can be a little patient. Also I will be trying some techniques that will be new to me so any and all input is welcome. We are all here to learn right!
I have chosen to use a Thunder tiger .46 engine and will add a quarter wave pipe. I will put the aileron servos in the wing but try to streamline them by placing them inside. I want to live skin the hinges at the ailerons, elevator. Yes, I will have a rudder. Probably a tail wheel as well.
From the looks of this thing I think anyone wanting to shoe horn a larger engine will not have a lot of trouble.
I am planning on sheeting the wings with balsa and then cutting the ailerons free. One of the items I am already unsure of is what the actual chord dimensions should be. The foam gets really thin and then a little thick again on the T.E. I think this little extra foam needs to be removed before sheeting the wing. Look closely at the pic in the previous post.

combatpigg

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This should be a very cool project!
Hopefully an experienced Zoomer builder will chime in and share his experience. I have heard that to get a nice uniform and razor sharp trailing edge, work in a strip of thin plywood before sheeting the wing with balsa.
I have doubts about using a dowel in the leading edge of a speed plane [as a wing hold down], but the designer of this plane obviously has had no problem with it.
Good luck with it!

vertical grimmace

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Thanks, combat pig. I was planning on using the thin ply. Darn...that was one of my surprises! It really works good.
I hope these pics look OK, I will work that out as I go along.
I am starting with the Fuselage. Here are the templates for the 2 formers and the wing plate for accepting the wing bolts. I will be using 4 wing bolts and no dowels. These will be band sewn and sanded. 1\4" aircraft ply for firewall. I will be mounting my engine using a backplate mount leftover from a Viper arf. It looks like it should work fine.

vertical grimmace

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After cutting out the firewall I tack glued it to an end of a balsa stick. This gave me control over positioning it from inside the wing saddle. I had to bail on the idea of using the rear cover quickee mount. It was too big. I now have a typical black fiberglass mount. This works just fine.
I held the engine on the outside of the fuselage with the back of the spinner installed to roughly locate where the firewall would go. I marked this with a sharpie. I also made a rough outline of the engine cutout.
I cutout for the engine using a dremel and cleaned it up with some 100 grit sandpaper. This worked well. After mounting the engine mount I began fitting the firewall where it should go and when satisfied I epoxied it in place with the engine and spinner mounted. I wiped the inside well with denatured alcohol to remove any release agent before applying the epoxy. I took some carbon tow and cut it up and mixed it into the epoxy to add strength to this firewall joint. After it dries overnight I will look at it again and may go over the joint again. This takes a lot of work and you must take your time and plan this install carefully. This is my first try at one of these but I feel it went well.
Next will be the tail section.

vertical grimmace

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Here are some better views. I have a very poor photo edit program sorry.

NoOneFlysAtMyClub

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VG,

Are you instructed to install the firewall first?

I mount the wing first, based off a fuse centerline, that determines my baseline. I can then install the firewall and stab at 0, if that is what is called for. For the Zoomer I would go 0,0,0, as we do our pylon planes.

If the firewall is off to some degree, when you set up the wing and stab off the firewall, the plane may fly at a strange attitude in level flight and turn who knows how.

Just my thoughts.

I have not ordered mine yet.

I want to see how well yours comes out first!!!

Tony

vertical grimmace

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RT, There are no instructions. I was lining up my spinner with the spinner ring end of the fuse. I gave myself some room if I need to make any adjustments. I will check all of my decalage and thrust settings as I go. I always set all of my incidence with the wing. I will do the stab after the wing is installed and I do my engines last. I may have a lot of faith in the kit's accuracy, but this is how I have always heard this was done. It is important to me to have a nice clean reveal between the fuse and spinner.

z06kal

Vert, I have lined up motors the exact same way and never had a problem. If worse comes to worse you can always throw in a few washers and shim the mount. With a molded fusalage I find it very unlikely that the mold would not be square with the fusalage. Just make sure when you sit the wing mounting that it is also square with the fusalage.

vertical grimmace

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That is what I thought as well. If the fuselage is not true than that sort of defeats the purpose of using glass and I would consider it junk. I am sure that it is not though. The glasswork is of high quality and looks very nice.

samtech

Ok, That is a cool! What a little screamer! I checked out that web page.... Anybody know if a 40-45 would fit in to that QM15 AJ-2 T-tail? It's bigger than a LR-1 and those fly pretty good with 40-50 sized motors... I wonder how big around the fuse is....
Vert, are you going to glass over the balsa sheeting or leave it and monocoat it?

bob27s

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Matney has a 40 size AJ ..... that makes a great aircraft with a sport .46 size engine in it

rmenke

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VG:

You'r doing just fine. The fuse is well done, engine/firewall centering by spinner good. Recommend you get the wing installed and set and use the wing as your datum line 0 for incidence. The elevator is a lot easier to adjust than the wing saddle. Set my engine same as you, checked after completing wing and tail, was 0 with a good incline-0- meeter. Kevin used carbon fiber at the wing trailing edge, think ply would be better for most. Glass the wing center section per instructions, monocote finish. If the guys in your club open class start to close on your speed, install a Jett 60 LX, will fit right in place of your TT and honestly idle better and give you a honest and scary 19K plus with the black pipe. You can still taxie out and take off normally. Engine becomes cheep after a couple of years, and it will still be running strong with just a little lovilng care. My first jett engine is now 6 years old and getting stronger, honest. ENJOY.

jeffk464

Since you mentioned not having a good photo editor I thought I would mention a great free one. "IrfanView"

http://www.download.com/3000-2192_4-10755180.html

vertical grimmace

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Thanks, that should help.

vertical grimmace

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Now onto the wing sheets in preparation for the wing construction. The sheeting at the root needs to be around 10" and at the tip around 7". This will allow a little over size to be trimmed later. You will need 12 3" sheets at 30" long. I used 36" and cut them to 31" for a little fudge factor. The plans call for 3\32" thick balsa.

I will glue 6 sheets together and then cut 2 skins from this large sheet. This optimizes yield from the material chosen. Check one sheet at a time and add short pieces of tape to hold the joint tight. Then add a long strip legthwise to cover the seem. The joint should be tight. If not sand with a long block or strip "joint" one edge with a straight edge and sharp knife. Continue with the rest of the joints taping them all together tight.

Flip the large sheet over and place it on the edge of your bench. You can now hang a sheet over the edge of your bench to apply glue. I am using aliphatic resin (Titebond). this sands easily and will provide an easy to work with glue. Super glue not recommended. Fold the sheet back flat and squeegee the excess glue. Now add another set of small strips of tape to hold this joint tight and flat. Repeat with the rest of the joints and let dry. This will provide very good tight sheets everytime.

vertical grimmace

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Now that the sheets are all glued up and dry you can remove the tape and flat sand with a sanding block. Focus on the glue seems and hopefully most of the glue was removed initially minimizing sanding.

Next lay the cores over the top of the wing skins to mark for cutting to size.

Now that we have the skins I am going to round up the other items that will go into the wing when actually applying the skins. I will be placing carbon fiber under the skins and also some 1\32" ply along the T.E. to help create a sharp, strong section that is important for going faster than the other guy!

vertical grimmace

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OK.. moving right along. I used CA to glue a 1\32"x 5\8" piece of ply along the T.E. on one sheet only. I will be using Poly U glue to glue on the skins. I really like how this glue works for this. I am also adding carbon fiber under the top and bottom of the wing skins. This should stiffen things up in those hard turns. You can see my press loaded with the cores and now it is time to let it alone until tommorow. Next up will be the stab and fin\rudder.

jeffk464

Question, do you have to cut the slots for the tailfeathers or were they cut by Matney Models?

vertical grimmace

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The slots will have to be cut. But the Stab area has been scribed into the glass so you have an idea as to where it goes. That might be a little tricky but should not pose too many problems.

HighPlains

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Rich, you have a nice thread going on the Zoomer.

I was wondering if you were going to glass the entire wing with 3/4 oz? I'm not too sure where your engine/pipe combination will put you in terms of speed, but the few F1's that were monocoted were very short lived (the good news was they weren't mine). I also used three layers of two oz cloth on the center section, because it gave a gentle transistion in wing strength from the 3/4 to the center section. Flex but don't break. Over the years of F1 racing, nearly every wing that broke in the air used a single 6 oz piece of glass, and the edge is where they all broke. The other thing, is that I would reverse the order of the center glass layer layup, so there is no chance of sanding through the longest piece of glass. Cover it with a piece of wax paper which is globally flexible, but locally stiff, and the epoxy resin will take it's shape and when you peel it off, the center glass will be very smooth with minimal sanding required.

vertical grimmace

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Thanks high plains.

Yes, I am planning on glassing the whole wing and painting. I cannot stand monokote. After all of this work to have something get saggy and need to be recovered eventually is not for me.

Also thanks for the tips on the glass. That makes a lot of sense. When using the waxed paper, would you put the wing back in the foam shucks? Or how do you apply the pressure to the wax paper to create the smooth finish?

I was planning on sticking the glass down with spray contact cement, then adhering it with quick dry clear poly u. Then priming and painting.

I do not plan on getting this plane over 140 mph so a true F1 strength wing will not be needed.

vertical grimmace

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I am really happy with how the cores came out. After trimming and cleaning up the balsa sheets, I checked the fit to the fuselage and it is very nice. When gluing the wing skins on, I kept the T.E. flush with the edge of the rear edge of the foam shucks. Also be sure to flush the L.E. to the front of the shucks. This aligned the thin plywood edge properly. I also made certain I applied enough glue along that edge so it would adhere properly and be strong. After some preliminary sanding on the T.E. the thin ply worked excellent and it is perfectly straight.

I have glued the L.E. balsa on. This is 1\2"x 3\8". I used titebond for this. I need to decide what shape to make my wing tips. I think with this design, you can do little things to personalise the shape of the tail and wing tips. So long as the tail area is not compromised I think just about anything goes. I need to decide what I would like to do here.

I will continue with the wings for now.

HighPlains

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I think you misunderstood me. The waxpaper is for doing the center section glass only, which is done after the 3/4 glass. You put in the torque tubes (if you are using them), then do the center section. I always used polyester for glassing because it gives the hardest surface and sands better than any of the other methods. Use a 3M block sander for everything (both before glassing and after), and you can have a surface that is a perfect mirror with no waves in reflected images. This also helps the speed, especially on the front half of the wing. Back third of the wing, it really doesn't matter.

Did you build a pad in the wing for the landing gear? I missed that part.

vertical grimmace

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The landing gear are short pieces of aluminum bent at a right angle and fastened to a plywood plate inlayed into the wing. I have layed out the position where I would like them to go and then I will remove the sheeting and foam to glue these plates in. I will use Poly u glue for this as I feel it is the strongest available.
I have also layed out the position of the ailerons and the servo location. I am going to live skin the hinges and the aileron servo will be buried into the wing with just the horn exposed. Maybe not the cleanest, fastest setup but it offers a very solid, no slop setup for the push rod. Also it will allow the mix of flaperon if desired to help slow the landings if needed.

I have shaped the L.E. now that it has dried. I like to use my block plane to do most of the work for this. Then I switch to a sanding block and finally I like to use a sheet of paper in my hand. This allows you to conform the paper to the shape and really finess the shape into what you want it to look like.
I highly recommend a Stanley low angle block plane. I know I have heard good things about the hobby razer planes but I find them to be worthless. A good low angle plane offers superior control and makes life much easier when building with balsa. This will save a great deal of time and improve quality immensly.
The wing is now solid and very straight. I am very happy with the progress so far. I feel this will build into a very nice plane when finished. The wing is really where you can see how good a design will fly.