Micro-Tee, foamie a mini Q-Tee AR6400 Slow Flyer
Having flown a few umx micro planes, and a profile foamy, I decided I wanted to scratch build a small plane to hopefully slow-fly around my yard and perhaps even indoors.
What I decided to do was to build a smaller foam plane patterned after Lee Reynaud's famous Q-Tee 1/2A flyer from the late 60's and eraly 70's.
Since I learned to fly on the 36" original Q-Tee, I felt this would be a great first
foamie scratch-built pane -- if I could make it fly as good as the original!
This is how I built the prototype.
SPECS: Wingspan: 21-3/4" (570mm)
Length: 17-1/4" (438mm)
Wing Area: 95 sq. in.
Weight: 60 grams w/1 S 240mah battery (unpainted)
Materials: 22" (558mm) of 1/8" (3mm) Carbon tube
39" (1 meter) of 6mm x 1mm carbon strip
3mm white Depron for fuse sides, tailfeathers and bulkheads
1mm white Depron for wing skin, fuse top and botoom panels
Glue: UHU POR and Gorilla White glue.
Note: The PDF plans have a 3" scale in the top left hand corner, so that if you
wish to scale the plane to a different size, simply print out the first page
of the tiled printout, then abort the rest of the plans print. Measure the
3" segment. (For example, to see if you've accurately scaled the plans
by 2/3 or 67%, the three inch scale would print out as two inches long.
Electrics: Parts are from PZ micro p-51, motor, gearbox and AR6400 rx.
Prop: GWS 5030 with GWS 1.5 mm prop saver
Battery: any 1S, I use home-wired 240 mah Hyperions
Last edited by TheRealMrEd; Jan 04, 2013 at 11:51 PM. Reason: PDF vanished from post -- plans updated.
The Fuselage and Tail Group
I began by printing out the plans using Adobe Pro and then taped the tiled sheets together.
At this point, you can either draw extension lines on the plans themselves and then draw pencil lines onto the 3mm depron to cut to the correct shapes; or you can print two sets of plans and cut out the pices of paper and tack paper to the foam using a tack spray coat that will peel off the foam parts later. That is what I usually do.
Next, I cut out the fuselage sides, bulkheads and tail pieces from
3mm Depron, 1/16" ply for the firewall and 1/16" balsa for the F-4A and F-4B
pieces. Using the plans I marked the former locations with #2 pencil, and glued the vertical struts to the depron right fuse side with white Gorilla Glue. Epoxy could also be used but is heavier.
After waiting for the glue to dry on the two vertical struts on the right fuse side,
carefully position and glue the cabane crosspiece between the two vertical struts.
Do all this over the plans to assure that everything is aligned and that the 1 degree of positive wing incidence is built in properly.
By the way the joints where the horizontal cabane meet the vertical sturts are the weakest joint on the whole plane. I am trying to figure out how to drill tiny holes in the c.f. to join these places with 1mm c.f. rod pins.
Build the left side using the remain c.f. strut parts, directly over the completed right side, to assure that the left and right sides will be exactly alike.
(I note here, the horizontal struts are suoosed to be on the OUTSIDE on their respective sides, NOT as shown in the pictures where they are both oh the right side of the verticals -- DUH!)
When these are dry, glue F1, F2, and F3 into place and clamp fuse sides together. The fuse from F1 thru F-4 is square, side to side. Let this all dry,
then glue tail pieces of the fuse sides together, making certain that the curve from side to side after F3 is the same on both sides. Building this over the plan will help.
When the tail pieces have dried, add the F-4 pieces where indicated, along with their 1/16" balsa vertical supports. While drying, make certain that the rear fuse curve/taper are the same on both sides, from F3 to the tail ends, to assure perfect alignment.
When they have dried, cut two pieces of 3mm Depron for the compartment "shelves" inside the fuse. The foremost shelf will be the "roof" of the battery compartment, and the floor of the "esc" compartment, if a separate
5A esc is used with the optional AP05 brushless motor. If you use the P-51 motor, then the upper compartment is left empty while the battery velcroes to the bottom of this front shelf.
The rear shelf, behind F2, is where the RX brick (AR6400 family) will be installed.
The shelves should be installed about 1/2" (12mm) abobe the fuse bottom.
Flies slow and easy. I fly this on a lot adjacent to my house (catty-corner across the street),
where the total area is maybe 100' x 100', probably a little less. I fly it ROG off the street, and land back on the street (most times).
One thing I will say -- with the UMX P-51 motor and a GWS 5030 prop, and a 1S 240mah 25C battery, it flies very scale-like. That is to say that with this power combo, you cannot yank it into a 45-degree attitude and climb out; you have to fly it on the wing.
Also, to do a loop, you have to climb and then dive to get up enough speed, and even then, it may just stall and fall out of the loop. Very easy to recover however.
That being said, at 22" wingspan, it is definately larger than most micros and yard flyers. Unless you were very good, you probable could not fly it in most condo or appt yards.
However, I use a 16" wingspan profile: http://www.wattflyer.com/forums/showthread.php?t=67988 that I cannot fly in this same area. It all depends on the flight characteristics.
Also, I am a lot older, and no longer as good a flyer as I usta was!
On to the Landing Gear & Other FUN STUFF!
Now it's time for the landing gear. Since I had a parts donor UMX BEAST, I just used that, to make life simpler. This was more or less a proof-of-concept build for me, with the foam and small size being new (to me). I traditionally have an upper size limit of a 44" wingspan, and build with balsa surrounded by a nice Monokote bag in which to carry the parts home... (an old 1/2A now Parkflyer type guy).
There are instructions on the plan for a make-it-yourself landing gear, so yo can go that route if you want.
In any event, cut two pieces of 1/32" plywood, 1/2" (12mm) tall, and just wide enough to fit snugly between the two front vertical cabane struts. Glue the front L.G.brace to former F2, and (only on the ends of the wood pieces) to the cabane struts. Sandwich the L.G. wire between, and the glue the ends of the rear-most L.G.brace. DO NOT GLUE THE GEAR IN PLACE BETWEEN THE TWO BRACES -- THE GEAR SHOULD BE REMOVEABLE!
Eventually, the gear is held in place by a piece of Blenderm micro hinge tape.
See photos for better explanation.
In the last photo, you will see that I have pre-assembled the tailfeathers with UHU POR -- which is used everywhere in this contruction, EXCEPT where I specifically recommend white Gorilla glue.
BTW, at this point allow me to apologize for any potential language errors; I spell perfectly, but typing -- not so much. And, I have been unable to get the spell-checker working on the posting gizmo, despite having downloaded it. Any tips would be greatly appreciated. Help an old guy out, will ya?
Also, in the last photo, you will se the wing ribs and center section. Start the wing contruction by first using the R-1 rib patters on the plan to create two 1/16" or 3/32" balsa ribs. My preferred method is to tack glue the paper patterns to the rib material, and then cut out using a #8 Exacto knife, the rib slots are made with a couple of passes with a razor saw. The spar notches on this model were not exactly tight; thank goodness for UHU POR.
Also, in the photo, the spar notches are shown at the TOP of the ribs -- an ill-fated idea on my part! DON'T DO IT! PUT THE NOTCHES ON THE BOTTOM OF THE RIBS IN THE TIME-HONORED FASHION.
Later photos will show this correctly on the finished wing.
Sorry for wandering off. Next, take the two balsa ribs and use as patterns to cut out the remaining ribs from 3mm Depron, 4 on each side, eight in all. They are all identical.
For the wing center section, I used a piece of the styrofoam packing material surrounding the UMX Beast in it's original box. Used a piece 1-1/2" wide, but the is plenty of 3/4" thick material to glue up two pieces if necessay. Using T-pins or whatever, fasten the two balsa ribs, one on each side of the styrofoam block. I used GREAT CARE to assure that the L.E. and T.E. of the two ribs was precisely aligned, so that the front edges would be dead straight across the front.
This was to assure that the Michael's cheapie foam cutter would cut a straight block of form center section, not some kind of trapezoid.
You could also simply cut out several thicker ribs of the R-1 pattern and glue up a center section already cut accurately. For this, I have cleverly provided three R-1 outlines scattered around the plans so that you can cut them out easily.
Well, that's it for now, next we'll start the wing, proper.
The foam cutter I used for the wing center section was barely wide enough to work. It consists of a cardboard tube, 2 "D" size batteries, a piece pf nichrome wire, a switch and a couple of aluminum-looking arms to support the nichrome wire under tension. I got mine at Michael's maybe 20 years ago to help with a school project of some sort. Wouldn't take much to work up your own, but I'm sure similar one are available cheaply. You could also rasp/sand the center section foam to shape.
First, referring to the plans, use a razor saw to saw off the center section foam to just where the short, rear center section balsa spar is located. Cut the cut-off rear part of the center section foam in half, front-to-back. Later, after trimming these two blocks to proper length to allow for the rear spar, they will be used on either side to round out a cut-out for the rubber band that holds the wing in place
Then, begin affixing the 6mm x 1mm c.f. strip for the main wing spar to the building board with magnets or your preffered method, atop the plans, which should be covered with Saran Wrap plastic. Then, affix the 1/8" (3mm) carbon tube L.E. to the board at the correct place. Last, glue all the wing ribs and the center section by glueing the spar in it's slot, and butt-joining the ribs to the leading edge. Weight everything down to keep the wing flat.
Next, cut the rear spar out of 1/8" x 3/16" balsa strip (or 1.8" x whatever the height of the rib where the spar will be placed), and glue it to the rear of the center section foam, as well as the inner ribs on each side. Cut the two remaining blocks removed from the center section foam to length by trimming their front edge to fit against the rear of the rear spar, to just come even to the line where the Trailing Edge (T.E.) will be glued. Let dry.
I made the T.E. out of a strip of balsa 1/16" thick and 1/4" wide. This is butt-joined to the trailing edges of the ribs and foam blocks and allowed to dry.
Cut a wing skin from 1mm white Depron. I cut mine to overlap slightly at the wingtips and cut it about 4-1/4" chordwise to allow for trimming at the T.E. later.
Pay attention to the "grain" of the Depron, making sure that the stiffness runs span-wise -- not chord-wise.
Before glueing down the wing skin, add two stips of 1/16" balsa at the rear tip of each wing, to create a bit of washout in each wingtip, as shown on the plans.
Make sure to glue the skin to each rib, the Leading Edge (L.E.), and the T.E.
If you think you can't glue all that before the glue sets up, you can do what I did -- glue the L.E., spar , rear spar, and T.E. only, running the glue spanwise, and then later, when you remove the wing from the building board, run a small bead of the UHU chord-wise down each rib from underneath. Then put the wing back down and weight it until this all dries. (Don't forget to re-install the removeable strip shims for the washout until after he wing dries.)
Make one last check that each joint is glued, add glue if needed, then let dry again. Trim the wing skin Depron to size.
Now, take your razor saw, and make a nice, square 90-degree cut down the center of the wing, cutting through the L.E., the spar, the rear spar, the T.E., and of course, the center section foam. Sand the edges of this cut somewhat smooth -- doesn't have to be perfect. (Here, I cheated and used my ancient Dremel table saw for a perfect cut.)
Now, thake the smallest peice of trailing edge stock balsa strip that you can find, and cut a 4-1/2" length that will provide the dihedral angle for the two wing halves. Measure the thickness of the wing at the tip, and starting from the thinnest edge of the 4-1/2" piece of trailing edge tapered stock, cut the strip to the same width as the wing thickness.
A word of caution here: traing edge stock in profile has three dimensions; the thickness, which we can ignore, and the bottom dimension and the top dimension. Look at the stock piece from the end. The bottom length of the T.E. tapered stock is shorter than the top dimension. When you trim this 4-1/2" piece of stock to the correct width, try to assure that the new top dimension and the new bottom dimension are the same. Otherwise, one wingtip will have a different dihedral than the other side. (Ask me how I know...).
You can also sand this angle, but correct it before glueing it to the wing.
In any event, using white Gorilla glue (you can use 5-minute epoxy if you are in a hurry.), glue each half of wing to the tapered strip as per the drawings. Blockup ONE wingtip to the dimension shown on the plans, use a straightedge to assure that the L.E. of BOTH wing halves are aligned, and then weight down the whole wing assembly until this glue has dried. This is your only chance to assure correct wing alightment and dihedral, so get it right!, Otherwise, saw the wing in half, sand in the correct angle and try again.
When this step is dry, take a 2" wide strip of fiberglass tape, silk, or whatever you like. Wrap it around the entire center section joint and and cover with to coats of WPU or water-based polycrylic finish, letting dry between coats. I used Mixwax from one of the big box stores.
Last, glue 1mm Depron wingtip pieces to each end and trim to sixe. (I still haven't done this.)
Also, please remember that as is mentioned in the first posting, the plans were designed to allow the aircraft to be easily scaled. With the right gear, a 12-inch one is possible. Of course, all materials must be scaled appropriately.
In fact, the prototype ended up this size because the width of the fuselage at this scale is just wide enough to fit the AR6400 brick, which is what I had on hand. I could have also scaled down the aircraft a bit more, but just widened the fuselage to accomadate the rx, which I may do later on.
I also wanted the undercambered wings vs flat wings for the slow-flying aspects. If anyone wants to chip in with an idea to do a simple heat-formed 2mm Depron wing with a WWI type airfoil, that would be even better!
I have been waiting on HK for a few weeks to get their AP05 motor back in stock, then I will
take the motor off the prototype, and use the AP05 with a 5A ESC and report on that combo's performance.
I will eventually build another copy, using c.f. tube vs. the rod I used, and trimming the trailing edge balsa down to 3/16" width. Also, I would trim the fiberglass tape down to 1-1/2" width,
to save a little more weight.
Other ideas, improvements, weight-saving tips from all would be greatly appreciated.
Meanwhile, if you haven't done so, please print out the plans to follow along with the build guide. It will make everything much clearer than my writing ability is able to do.
Beginning of the end.
Some notes about lining up and fastening the tail group. First, use T-pins or straight pins to temporarily hold the assembled tail group into place. Then, place a piece of wood or a yardstick across the horizontal wing struts. Then, sight down the length of the aircraft from the front, and then the rear, to make certain that the horizontal stabilizer is parallel to the ruler laid atop the wing struts. If it is not, lightly sand the top of the fuse on the side where it's too high and recheck. (This assumes that the fuse is even from side to side!).
When all that lines up, take another pin, and temporarily push into the top center of former F3, and then tie a piece of sewing or other fine thread to the pin. Measure the distance from the pin to each of the tips of the elevators, where they meet at the horizontal stabilizer. (See 3rd photo). This dimension should be the same on both sides. You can have a tiny variation here, but the plane will fly better if it's dead straight. When everything is aligned and square, glue the tailgroup into place, holding it with pins, tape of whatever until the glue sets.
After that, you can install the AR6400 rx (or your own choice of same). I put it at a rather forward spot, and held it in place with a little silicone sealer until that dried. You might have to shim up the rx with a little foam to clear the servo gears from the mounting platform.
Note in the photos that a small hole has been cut into former F2 to allow the wires to go to the motor, as well as down to the battery. Do whatever works best for you. Also, I knew that I would have some problems hooking up the control rods, so I left the top and bottom sheetong off the fuselage until this was done.
The control rods are made up of .028" - .030" carbon fiber rod, .020" - .022" piano wire ends, and some .5mm - 1mm heat shink tubing, glued together with CA before shrinking the tubing.
I put simple "Z" bends in the servo ends of the control rod wires and "Z" bends and a "U" bend for mechanical adjustment in the rearmost wires. I used control horns salvaged from a donor UMX Beast. One useful tip: the hardest part here was folding the wires to the c.f. rod until the CA was dry. For this, I finally found that a set of rubber-tipped fly-tying hackle pliers are the best!
Also, I shrunk the tubing after installation with the tip of a soldering iron, as use of a heat gun would have fried the foam due to the tight perameters.
One other thing... before finalizing the length of the pushrod setup, make sure to lock the moveable control surces at dead neutral with two pieces of balsa and a clothes pin, etc. Then turn on your radio, then the RX, and let the servos center with zero-zero adjustments on the radio. You can the adjust trim later either mechanically with the "U" bends in the wire or the trim on the radio.
I went to a lot of effort to make certain that my elevator control rod was in a "pull-for-up" position atop the elevator. After flying the plane, I found that this was not needed, as long as you secure the middle range of the control rods to prevent bending under flight loads. I would recommend that you install both rods underneath the horizontal stabilizer, and through the sides of the fuse. While you install the control rods through former F-3, and through the fuselage sides, just poke a piece of c.f. rod the same size through the foam, and this will give good support on both ends, yet still allow the rod to slide freely. A little piece of foam support at about former F4 will take care of the middle.
Last photo is simply a size comparison with the MicroTee's big brother the E-Tee, which is simply a modified, electrified Q-Tee. Oh, and in fact, those aluminum struts on the big one ARE too heavy!
May I remind you about a certain pond?
Anywho, I'm here. Glad to see this out here Edster. I gotta clean up my basement so I can get to my workbench and try one of these little guys. If I can get one built, maybe we can get together sometime (prolly after the holidays) and see if we can still jointly commit aviation.
Just ain't gonna walk the dog with this one.
UT - hisself
Last edited by catrancher; Oct 24, 2012 at 02:12 PM.
The PZ UMX P-51 motor
To install the P-51 motor, you must add the depron shelf that the motor sites on, and it is installed with a five-degree down angle at the front. The motor is attached to the mounting shelf at a 2 - 3 degree angle to the right. I used silicone sealer to glue the motor in place. Since this is a prototype, I was not trying to be particularly neat, as you can tell. Picture two shows the hole in F2 for the motor wires and battery wires. The motor wires are fed straight thru the "esc" compartment, and onto the Rx plug. The esc compartment will only be used if a brushless outrunner with separate esc are used, which I plan to do soon, both in 1S ans 2S versions for the sake of the research.
Perhaps after that is done, I'll paint it.
The third picture shows a 1S 240 mah battery in place. It is velcroed with micro type Velcro. If you elect to use a 1S 160 mah or so battery, you will probably want to cut another hole in the F1 firewall, to allow the smaller battery to slide further forward for better balance. I tried this, and had to add Velcro to the underside of the motor shelf to attach the smaller battery.
I got the battery, prop, spinner and prop saver ( as well as other items) from here:
The last photo (for now) shows the two motors that I will use for the brushless conversions. They are the AP05 and the HMW1400-2000. The AP05 shown is sadly only the 3000kv version from HK. Am awaiting an AP05 5000kz from SkyRC for the 1S version, as it is claimed to offer 90 grams thrust with a 5030 GWS prop. If I can get 70g or so, I'll be happy.
When add to this thread when I make each of the modifications.
As always, feedback or questions are always welcome. I'm trying to learn something also, which I can then inject into the devious brain of my good buddy and fellow designer, the CatRancher.
Well, my new AP05 motor finally came in, and I will be showing that installation as soon as I can get to it.
Meanwhile, I've been experimenting with a new wing, simply because the original wing is very heavy. A new one could have been built, but I don't have the smaller
carbon fiber components on hand, and have been too busy to trek to the LHS, which doesn't have a lot of stock, anyway.
So, I decided to go with what I had on hand. I chose a piece of 2mm Depron, which happened to be only 10 inches long and the stiffer dimension (spanwise of the wing), so that I could not simply build the original size wing. The foam was 10" wide because that's what I ordered from RC.Foam, to save ungodly postage on the full-size sheet!
Because I wanted to stay around 100 sq/in in size, I decided to go with a 20" wingspan and 5" chord, or two pieces of 2mm Depron, each 10" x 5". I popped these into my trusty Kenner Easy-Bake WING Bake unit (just kidding, built it from online plans and photos), and a while later had a pretty good undercambered wing -- in pieces -- ready to go. I used the original plans to cut out the now deeper cutout on the rear wing edges, to allow for the hold-down rubber bands.
I then sanded the wing half inner edges to about a 5 degree angle (eyeball), then glued the two wing halves together, butt-joined, with both leading edges lined up by a steel ruler. I used foam-safe CA here. Then, I cut two10-1/8" pieces of 1/8 square spruce that I had laying around. (1/8" hard balsa would also work fine here). I glued these to each half of the wing, overlapping at the inner join.
I then glued the overlap of the spars with the CA, and left everything to dry.
Last, I taped the joint with clear tape for additional support. The photos will make this much clearer than my ramblings.
During the first test flight, I ran into problems! The plan zoomed like crazy, and was hard to turn and control. After analyzing the situation, I soon figured out that the rear edge of the wing was WAY lower than the front edge. Too much wing incidence! There should have been 1/16"- 1/8" differerence.
This refers to the angle of attack of the wing versus the horizontal stab angle. Sine the horizontal stabilizer on this plane is 0-0, the leading edge of the wing should be slightly higher than the rear.
First, I tried 2 pieces of 3mm Depron as shims at the rear of the wing cut-out. Not enough, so I added another piece, for a total shim height of 9mm at the trailing edge of the wing, at the cut-out (see photo 3).
EDIT: After further testing I fell back to two pieces or 6mm total for the shim -- Ed
After a mishap with a try in my tiny back yard, I suddenly discovered that when the wing comes off, it is far better to have the shims glued on, rather than just stuck in -- fewer pieces to gather up!
The new wing flies very well. All-in-all, I would rather have more span and less chord, because there is less drag that way. BUT, since this is a slow-flyer, the extra drag just helps. More importantly, this simple wing change brings the all-up weight of the Micro-Tee down to 46-47 grams, vs. the original 60 grams, hitting the little UMX P-51 motor right in it's sweet spot for power.
Next, I'll cover my attempts at a Kline-Fogleman air foil wing.
Last edited by TheRealMrEd; Nov 15, 2012 at 08:19 PM.
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