After assembling and running the fan once, I made myself an inlet ring. It quietens down the whistle and actually increases the thrust.
This is a lamination of 1/4" balsa sheets turned cross grain for strength.
Make the lower ring 1st and get it fitted so it just slips over the fan housing. Glue it to the top ring and insert the fan. Trace around the inner housing and cut out that circle. Sand to match the inner housing and round the edges.
1/20/08
Today is when I got bored and started to work. The fan former is made from 2 pieces of 1/8" lite ply turned crossgrain for strength. Simple 6.5" x 6.5" square, fan opening dead center and top rounded to a 6.5" circle. 3/16" ply used for mounting rails.
Fan housing bolted in. I used 6-32 machine screws and blind nuts. Before bolting in the fan, I added 1/4" notches to the former which will later be occupied by 1/4" support stringers for the fuselage sheeting.
Inlet ring checked for fit. It hasn't been made permanent (glued in) until I decide whether to use it or attempt inlet ducting.
Thrust tube constructed from a clear desk protector mat. Formula = 15" long, 15.5" front and 13" at the the rear with 1/4" overlap for glue joint. Makes a 4" diameter exit at the end.
The rear tube support was made from single 1/8" lite ply. 5" x 5" square with the top radiused to a 5" circle. 4-1/16" tube hole in center.
Basic fan box framed. 1/4" x 1/2" balsa used on both lower sides. 1/2" x 1/2" on top since it will also serve as the base for the vertical fin. Length of all 3 supports, 15".
The other pieces of my package from China. A 120 amp Hextronic ESC and a KB45-08XL 1700kv inrunner. The motor I have doubts about. It makes great power, but heats up quickly. It could really use better cooling. The ESC seems ok and I'll probably run it in the Mirage when the time comes.
Fan assembled and ready to put back on the shelf until I get ready to use it. On a 3s lipo pack this unit makes 635 watts @ 58 amp draw. On a 4s pack it produces 1150 watts @ 88 amps. I plan to run it on a 6s setup but don't have readings for it yet. Still have to make up a series harness for that.
1/21/08
I cut the ribs for a built up wing tonight. Chances are this will be the last entry on this project for a while since my Mirage 2000 kit is supposed to arrive tomorrow.
It's been a while since working with balsa so I cheated here and used a set of F-18 .040 glow, pusher prop plans that I had laying around. It will give me a 42" wingspan and can be adapted to a low wing configuration. Couldn't really do anything else with it today since I don't have the right size stock for the wing spars.
1/27/08
Turned out that my Mirage didn't arrive as planned. It was the GWS J-10 that came in and I'm not in the mood to work on it yet. I decided that the F-18 wing wasn't going to be big enough. So, I spent a couple of days drawing up my own wing plan and rib templates.
This one will give me a 50" wingspan with a root chord of 19" (at fuselage sides) and tip chord of 7-1/2" on a symmetrical airfoil instead of the flat bottom from the F-18 plans.
I added 1/16" ply doublers to wing ribs 2 & 3 which will be used later on for retract plate installation. This will be my last entry for a while since the Mirage is arriving tomorrow.
2/9/08
Finished the Mirage a couple of days ago and since it was a crappy weather Saturday went back to work on this one. Here, the trailing edge has been tapered and sanded flush with the wing ribs.
Top wing spar (1/4" sq spruce) and leading edge (1/2" sq balsa) are added to the wing. The leading edge is taller than the wing ribs as the wing sheeting will butt against it on the front and lap over on the trailing edge.
The spar & LE process is repeated for the other wing half and 1/16" balsa sheeting added. The wingtip has a 1/4" shim underneath it while sheeting to build in a little washout for better low speed handling..
Top wing sheeting completed. I need a bigger work bench! The full wingspan will not fit on the one I'm using.
Landing gear rails installed. I had to cut away quite a bit of the inboard wing rib to clear the air cylinder of the full sized Robarts. (I had bought them to put in my A-10 and they were too big for it).
Retracts semi-installed and mounting holes drilled. Since I don't have any #6 bolts long enough to install the blind nuts with am pretty much done until I can pick some up. Aileron servo well has also been framed up.
2/10/08
Very little accomplished today since I'm in need of some hardware before closing the wing. But, got bored and added in 1/16" balsa shear webs between the top and bottom spars, leading edge sheeting and did the basic shaping of the leading edge.
2/12/08
A little progress made but not much. Working tends to cut into my building time. Blind nuts installed for the retract mounts. 11" aileron Y harness and 9" extensions laid in place.
Trailing edge sheeting added and servo bay cutouts made. This is where my time ran out for the night since tomorrow is another work day and I need to get to bed.
2/13/08
Managed to finish the lower wing sheeting tonight. (That was after testing the new 3700ma 5s Evo 25 in the Mirage. It now exceeds a 1 to 1 thrust weight ratio.) Retracts fit in nicely.
Wheel wells opened up using a hole saw and then a dremel with a sanding drum. 2-1/4" Sullivan Sky-Lites dropped into the holes. Gear legs will be 4-1/2 to 4-3/4" in length. Time to hit the showers and call it a night for now.
2/14/08
Before going to bed last night I dampened a couple of pieces of 1/16" balsa and wrapped them around an aerosol can with rubber bands to hold them in place.
This evening I used the pre-formed pieces to make the wheel well liners and glued them in with medium CA. Not a lot done, but it's easier on my wallet if I don't build too fast. Now I need to round up some 1/2" x 1-1/2" aileron stock for the trailing edges and ailerons.
2/17/08
Just wasn't in the mood to "work" this weekend. (Did do some flying though, yesterday & today) I couldn't find any 1/2" aileron stock so wound up making my own. 3/8 x 1-1/2 stock with a 1/16 balsa lamination on each side.
Trailing edges attached. 3" on each tip, centers are 10" each side and the ailerons 12"
Ailerons center marked and slotted for hinges.
Hinge locations marked in trailing edge and slots cut. Ailerons slipped back into place to test fit. That's where I'm calling it quits for the evening.
2/20/08
Did a litle more tonight. Can't get real ambitious since I'm almost out of 1/8" balsa. (more ordered today along with sopme more CA.
Here, the 1/8" lite ply wing saddles have been added in. I used some of the 1/4 blue foam to make the wing cutout pattern before cutting the ply for the wing openings.
4"x1/8" balsa outer fuse (intake) sides laminated to the 1/8" ply. The rear fan housing was done with a seperate piece as 36" was not long enough to make it in one. Overall length of rear fuse is about 42-1/2".
Wing checked for fit.Looks pretty close to me. At least, for now.
1st couple pieces of the front wing mount cut. The base measures 1-1/16" high by 8-7/8" wide. The inner (front fuse) former is 4" wide x 8" tall with a 3" radius on the top. Still one more piece to cut but need some more lite ply to cut it from since the grain is running the wrong way in what I have on hand. (that's big enough to cut it from)
1st 2 parts laminated together using thick CA. Once the other part is cut, it will give me a 3/8" thick former for the wing dowels to fit into and a 1/4" inner fuse former. Each piece will be ran cross grain form the one it's laminated to for strength. Taking time to add to the page that's all for tonight. It's this old man's bedtime. ;-)
2/23/08
A crappy weather Saturday, so got a little accomplished today. Finished laminating the former and added a couple of holes for lightening and to allow air to flow through.
Former attached to outer fuselage sides with 30 minute epoxy.
Rear wing hold down block made from 1/4" x 3" hardwood block I found at Home Depot. I'd planned to use 1/4" aircraft ply but found I was out. And there are no hobby shops in my area open on Saturday.
Wing hold down block attached with 30 minute epoxy.
Wing center marked and holes for front dowels drilled through into the wing. Once drilled the wing is removed. Dowels get installed into the wing with 30 minute epoxy leaving about 1/2" exposed to plug back into the former.
Wing alignment checked/adjusted and holes for the rear hold down bolts drilled.
Holes threads made with 1/4-20 die.
Threads hardened with thin CA.
Forward (inner) fuselage sides cut from 1/8" x 4" x 36" balsa sheet. Leftover 1/4" blue foam was used again to develop the pattern before cutting the wood.
Wing re-attached with a sheet of plastic wrap between it and the fuselage to make sure it doesn't get "permanently attached" during this step. Inner fuse glued to rear wing mounting block and forward former.
3/32" balsa used (cross grain) to add strength to the structure as well as become the bottom inlet ducting.
2/24/08
Did some flying today even if it was still semi-"yukky" weather, so not a lot accomplished. Added another 1/8 lite ply & 1/8" balsa (lamination) former to pull the forward fuse back into place.
And completed the 3/32" crossgrain balsa bottom "inlet ducting"?. I figure the ramp up will be better than the square edge from the wing mounting former that it covers.
Also added the 3/32" upper fan housing sheeting. I'll blend it into the 1/8" lower side after the water used for bending it evaporates. An old spray bottle with plain old water in it is really handy for this.
2/25/08
1/8" balsa and more ca arrived today. Inner fuselage uppers added. Single sheet 4" width cut to be flush with tops of front formers and tapered down in rear to be about 1/4" below the fan former.
A few more vent holes punched in and 1/4" square ducting support added. Had to notch the upper inside fuse for the support clearance, but that's what happens when making it up as you go. ;-)
Not shown in this picture is the 1/8" balsa cap that was glued to the inner fuse sides from the support beams back. Tapered front to rear (V) to match fuse sides. Also the 1/4"x3/8" strip glued to the center line of it for front outer fuse sides (intakes) to glue to.
Forward "inlet" sheeting was made by gluing 2 3" x 36" x 1/8" balsa sheets together. 1/8" is a little tougher than 3/32" stuff. So, after trimming to approximate size soak the wood pretty good and walk away from it for about 10 minutes before attempting to form it.Once it's flexible enough, use medium ca on all the surfaces it will contact and press it into place. That's all it's getting tonight.
2/26/08
Front fuse doublers made from 1/8" lite ply. Since I don't have the luxury of a laser cutter did the next best thing and "swiss cheesed" it with a drill & hole saw bit to save a little weight. Uncut areas are where internal formers will be attached.
Doublers attached to the existing 1/8" balsa sides. There is a taper in the doublers and the lower edge is 1/2" higher than where the balsa outers will be attached to allow for the 1/2" balsa triangle stock
Front outer 1/8" balsa sheeting added.
Had to take a break from the nose and attached the inlet ring to the fan former after hardening it with thin ca. (Thought about it and decided I should do it before forgetting it until it was too late. <g>) Fan bolted in to insure proper alignment, a few drops on medium ca on the back side and slipped into place. Fan then removed and a moderate bead ran around the outer radius.
2/27/08
Made 2 forward formers tonight and attached them. Nothing else done since I went to the funeral home to pay my final respects to fellow RC'er and local "Top Gun" pilot, John Walton. Not really in the mood to work but did anyways to take my mind off it for a while
I didn't know John that long. Only a year and then, only on Sundays. Still, in that time I could tell that he was a great all around person as well as a great RC pilot.
He's been the pilot in most of my "product evaluation" videos and like many others, I'm going to miss him.
2/28/08
Dug out the nose gear and mounted it to a left over piece of the hardwood used in the wing mount. 6-32 bolts & blind nuts used. Width 3.5" height 3".
Mount positioned inside fuse and location marked. Since it's a 105 degree mount a little angle is needed to get the strut at a 90 degree down angle. On the good side, it will guarantee that the wheel makes it all the way inside when retracted.
Landing gear block attached with 30 minute epoxy. 1/2" triangle stock added for a little extra strength.
Wanted to do sometihng different so started on the turtledeck. Front & rear formers cut from 1/8" lite ply. 3/32" balsa used for the side. 3/16" hole made for rudder servo linkage and a couple of 3/8" holes for battery & servo wires to run through.
2/29/08
36" NyRod (wish it was 48") for rudder installed. 42" servo extensions for elevator & ESC laid in place and 12 gauge battery feed wires made up. (wish they were longer than 36" too but do at least they make it to the cockpit area).
Wires routed and taped into place.
Second side glued into place.
After adding 1/4" balsa triangle stock along the top inside edges of the turtledeck sides, a 1/4" sheet cap is glued on and sanded to rough shape. Since I have to work tomorrow (inventory) that's all that's getting done tonight.
3/1/08
After 9+ hours of inventory at work wasn't too ambitious, but did manage to cut & assemble the two flying stab halves from 1/4" sheet balsa. The multi directional layout of the grains help add strength.
3/2/08
Went flying today and fried the Great Planes motor in my Mirage. (Guess it wasn't such a bargain after all At least there wasn't much damage to the airframe).
Here, 1/4" slots have been cut for the torque rods to go into.
3/32" sheeting added to both sides to give more strength and to build up the thickness to around 3/8" overall.
After marking the centerline of the leading & trailing edges, the leading edge has been tapered. Taper measurements are 3" at the root cord and 1.5" at the tips.
3/3/08
Trailing edges get tapered. Measurments were 4" at the root and 2" at the tip. The masking tape gives a visual reference line while shaping and is somewhat resistant to the sandpaper keeping you from sanding too far. This same technique was used on the leading edges.
The stabs are VERY tail heavy from the rotation point so added a couple of lightening holes to the aft portion. You might notice the slot cut near the leading edge. Even with the holes, it still took 1/2 oz. of weight (in each) to balance them.
The lead weights are semi visible in this shot. The carbon fiber rod is not being held tight and balance is very close to neutral. This is a step that I think many overlook when I see planes sitting with the stabs drooping after the radio is turned off. Maybe it's not essential, but it does releive the strain on the servo to hold it in the neutral position.
3/4/08
Not working on the project tonight or the rest of this week. Instead, trying to get caught up on some household chores before taking off to Lakeland for Florida Jets on Friday.
I'm hoping to find myself another motor for this one while there as I have no faith in the one from China surviving even a test flight. I cleaned out my "piggy bank" tonight and cashed in a little over $300.00 in coins so that should cover something decent. I've seen Neu motors and Mega's suitable for 120mm fans in that price range on the internet, and hoping to find one "on sale" for even less at the event. I need to dind a good one for my 90mm fan, too.
3/10/08
Still haven't started back to work on my build. The weekend was filled with shooting video at 2 different events and uploading it to the website. (Check the videos page if interested, FL Jets & Dick Coles Memorial).
Today my Cermark F-16 arrived and I had to fondle it a little bit. Shown here with my little Phase 3 EF-16 for a size reference. Not to worry though, I'm not starting on this one 'til project EDF-120 is finished.
3/14/08
Sure was hard going back to work on my stick build knowing that the Cermark 16 is going to look so much better and with only a fraction of the labor involved in this one. On the other hand this is something to do while waiting on parts.
I will confess, I more or less traced the vertical from the F-16 to make my pattern on this one.
A few lightening holes added before adding 3/32" sheeting to the 1/4" balsa structure.
Cross grain sheeting added for strength.
Assembly sanded to an airfoil shape using the same method as on the horizontal stabs. The rudder is not sheeted, just beveled to a taper on the trailing edge.
3/15/08
One of the down sides of making it up as you go along. Here a portion of the 1/4x1/2 balsa rail had to be cut out and replaced with a 3/8x3/4 hardwood blocks for the stabilator torque rod to pass through.
I wanted to set up the elevator linkage but didn't have any high torque servos in my collection so decided to build the lower the wing fairing. Sides are cut from 1/8" balsa and arranged to leave the center section open due to the retracts.
1/4" triangle stock was added to the inner sides prior to adding the 1/4" cover sheets and blending into the wing.
I hung this assembly from my digital fish scale before calling it quits for the day. Current weight is 5 pounds.
3/17/08
I must be getting slow in my old age. It took me 2 hours to fabricate this retract valve/servo mount and linkage to operate it. After the way it kicked my tail, I'm done for the night and going to relax a bit.
3/18/08
Mounted the retract valve assembly and air tank. There will be a removable hatch over this eventually, and there enough room above it for the battery tray to hold 3 (or 4) 5000 ma 3S Evo 25's if I so desire. 2 5s packs should be no problem. Also marked the main gear legs for bending.
3/19/08
Main gear test fitted in place. I took the legs to work with me because my little vice just isn't strong enough for bending the heavy wire. (Having access to the torch there didn't hurt either) <g>
With the main legs in place, bolted the wing to the fuse to measure the front leg and found a major error in my plans. With the nose fully retracted it will bring the wheel up too high.
More on this when I fix it. I'm done for the night.
3/20/08
This project has been dragging along for a while now. Today marks 2 months since starting it. I couldn't do my nose gear relocation due to being out of 6-32 blind nuts, so built the rear hatch. 1/4" x 4" balsa sheet used. Two pieces edge glued and cut to fit.
1/8" light ply tongue used to lock it in at the front. 1/4" square balsa rails to keep it from shifting side to side. Holes drilled and short pieces of hardwood dowel added where the attaching screws go through into the stabilizer mounting blocks.
Attached to fuselage and initial shaping started, but ran out of allotted working time for today. Tomorrow, I can stop by the hobby shop on my way home from work and pick up some more hardware.
3/21/08
After stopping by George's and picking up some hardware was able to attach the new nose gear mount to the fuselage and measure the front strut for length. After the stop by Georges this is all I had time to get finished.
3/22/08
A rainy yukky Saturday. Added a couple of 1/4" spruce servo tray mounting rails to the fuselage. The nose gear now swings to the front instead of to the rear as originally planned.
Steering and rudder servo tray made from 1/8" light ply. Steering cable guides constructed from 1/4" balsa with 1/32" ply laminations on both sides of them. Nyrod outer tubing used for the steering wires to run through.
Servo tray installed with 3 2-56 screws on each side. This way it's removable in the event I need to get to something underneath it at a later date.
Air tank fill valve mounted in the tray as well.
Since I don't have cables for the nose gear, decided to rig the rudder. So, covered and hinged the assembly. A 3/32" aileron link was used which will keep the linkage hidden.
Vertical fin and rudder attached to the fuse with epoxy and allowed to cure. Rudder linkage then attached to the nyrod
With the linkage done, rear turtledeck sides and top added and rough shaped. That's where I'm calling it quits for tonight.
Yes I know... my desk is a mess.
3/23/08
Had an idea for the steering so rounded up some picture hanging wire and rigged the nose gear steering. I'm going to have to replace it since it's a little too stiff but at least found out that I won't have to cross the cables for the nose gear and rudder to work in the same direction.
After covering the vertical fin yesterday decided to do the stabs today. Tops are red, bottoms blue. While at it re-attached the wing to check the angle of attack with 2.25" mains and a 2.0" nose wheel.
For a different view brought it into the living room and set it on the floor. It's finally beginning to look like something although it won't make it into a 10 lb ready to fly weight. 12 maybe but guessing closer to 14. Current weight as shown is 7 lbs. Probably another 2 lbs for motor & fan and about 3 more for batteries. There are still some other pieces to make yet, too. Nose, canopy, etc.
3/25/08
Just not in the working mood I guess. I have about a 4-6 week wait for a Neu 1527/1.5Y anyways. Seems like they are out of stock
everywhere
in the US.
Wasted a good hour trying to fabricate a centering mechanism for the nose gear and then found it wouldn't work as it made it bind when down. Gave up on that idea and made the cover for the nose gear. The opening is a bit wider than I wanted but don't have to worry about the wheel turning sideways and snagging it. Not permanently attached yet, just testing for fit.
3/27/08
Last night I cut some bluecore foam nose pieces but didn't bother with taking pix. Today my heavy duty metal gear servo's arrived. (ordered 3, one for this one and two for the stabilators on the Cermark 16.) Servo mount made and glued into the fuselage side, elevator linkage installed.
Fan and thrust tube re-installed to check for clearance. The bottom of the servo makes a slight impression into the tube. Not much, but it's touching. I'll live with it since I couldn't find a servo with this much torque any thinner. Guess my fuselage should have been 1/2 to an inch wider.
3/29/08
All bluecore foam pieces cut. I made myself a 1/8" light ply template for these with plans to use it as well.
Laminations glued together and marked for top view. I used the 1/8" ply template for a center since I have a tendency to stand large models on their nose if there's no rack available. This way it won't be as likely to crush the nose.
Nose attached to fuse and shaping partially complete. (rasp cut done, will be finish shaped with 80 grit paper.)
More bluecore cut for canopy. No ply doubler need for this but it is attached to a 1/4" balsa base. (Access hatch for batteries, air fill etc. There is a 1/8" ply tongue attached to the bottom to lock the front in. Later a spring latch will be added to hold it in the rear).
4/1/08
Taking another "break" for a few days. Not that I wanted to. It's reaching that point where I want to apply some covering. But, my back decided it needed a little vacation on Sunday while at the flying field. Was fine when I went out Sunday morning but walking back from the flight line it just started hurting.
Spent all of Sunday evening in the floor and except for work (good thing I have a sit down job) have been doing the same Monday & today.
Getting better but still not good enough. Just adding this entry and going back to the floor.
With the nose and canopy shaping done, it's finally beginning to look like something and gain a "personality". Makes me want to get it finished and see what it will look like in color.
4/6/08
After spending much time on the floor with my back this week finally got a little more accomplished today. Top of the wing is covered with red & white Econo-kote.
Wing bottom done in blue & white. Ailerons will be covered in white when I get that far.
But 1st I wanted to see what it would look like with the wing attached. Just to give a little size perspective, I'm 5'-10" tall.
Main gear has been installed and plumbed with air line. There is a quick disconnect between the wing & fuselage. It also has a slow leak that I still have to track down. Unfortunately, the lighting in my living room doesn't work well for photos, but I'm starting to like the way it looks. Not going to push my luck with my back, and calling it quits for today.
4/8/08
Last night I made the hatch for the retract and radio compartment. Tonight I started the blue covering on the bottom of the fuselage.
This is as far as I got. It's so big that it's a royal pain in the ass to get to. Especially in my little back bedroom "workshop".
4/9/08
Finished the blue and got started on the white. Still doesn't look like much accomplished but it does represent a little over 3 hours worth of work.
If I were to pay myself $10.00 an hour, I'd already have more in this one than what the Cermark 16 will cost me when completed. Good thing this is "just a hobby". And, it's something I wanted to do a long, LONG time ago. Then, the "stuff" to do it with wasn't available. Now, it is.
If curious about the hatch construction, it's just a simple 1/4" balsa assembly. 1/8" light ply tabs hold it in place at the rear with a single 2-56 srew attaching it in the front. 1/4" square stock keeps the crossgrain from bowing (a 4" wide sheet wasn't quite wide enough to run it long grain. so had to edge glue 2 together) and keeps it centered on the fuselage at the same time.
4/10/08
Red covering started, after making a quick foam tail cone for the rear of the turtledeck.
After finishing covering the ducting portion decided to do the turtledeck in sections due to the compound curves in the very rear. Both sides around the rudder is done.
Right side of turtledeck covering completed and thats where I call it quits for tonight. Trying to hold myself to 3 hours or less per night, but wanting to see what it will look like at the same time. With exception of waiting for a motor, I should have it finished by the end of this month.
4/11/08
Fuselage covering completed. Canopy still "to do". Enough for tonight.
4/12/08
I piece of 3/16" nusic wire heated with a little torch worked well for making the canpy latch mounting pocket in the blue core foam.
Latch installed with 5 minute epoxy.
Hole drilled into turtledeck for latch pin. To mark the location for it, I put a little dot of white paint on the tip of the pin. Retracted it, and after positioning the canopy let it slide back out to make contact.
Canopy checked for fit (again) prior to covering.
Canopy covered (2nd attempt) with white EconoKote. I tried covering it with Chrome Mono-kote 1st, but wasn't happy with the way it came out. It just won't heat shrink the way the other colors do.
4/13/08
No real work done on it today but did take it to MCRC field for a little photo session and some "show & tell". The rear looks a little empty right now. I still have to make a tail cone for it (or find a styrofoam cup the right size.) From the front it looks "ready to go" though. For stats, current weight is 7 lbs. 12 oz.
I'm guessing 13 -15 ready to fly and hoping to get about 12 lbs. thrust from the fan.
4/15/08
I finally covered & permanently attached the ailerons last night before stopping to watch Bones.
Tonight with such great programming as American Idol, Biggest Loser & Beauty and the Geek it seemed logical to build the aileron servo trays. 1/16" ply used along with some of the leftover 1/4" hardwood for the HS-225's to screw into. There's also a piece of servo tape between the servo and ply plate.
4/16/08
Aileron servos mounted and linkage attached.
The 6 screws go through the balsa sheeting and into the 1/4" spruce rails underneath. After running the screws in once they were removed and the threaded holes hardened with thin CA.
Not shown is the heat shrink tubing applied over the servo lead connections where they plug into the Y harness. Also attached the flying stabs but saw no real need for a photo of that. It's getting very close to being done.
