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Posted by Old_Pilot | Oct 14, 2014 @ 07:25 AM | 1,365 Views
Several of my buddies at the club asked me if I could make the Jetstream look like the F-117......I cut it out yesterday and will finish the assembly today...hopefully fly her Thursday...weather permitting....The F-117 doesn't translate well to elevons.....but it's close

Parts are on 36x48 paper......blanks are 30x40x3/16 PFF (outline).......Assembly drawing is not to scale

She's a lot easier to cut out ...no curves.....I used a 48" long aluminum sheet rock ruler...took about an hour

Update......My wife said....."OOOO...that's wicked"

The yellow tape is "Frog Tape".....anybody ever used it for hinges ?

Update...flew her this morning....she's a handful...I cut the throws down to 50% and she would still do a nice tight roll......biggest thing I learned........don't fly a flat black airplane against an overcast sky in gusty winds.......I got her down with no damage.. got the right gust at just the right time and plopped her down right in front of me...not even a grass stain....

Today was a much better day to fly......clear and calm...and the runway was cut this morning......perfect

Big Al is the launch crew, I'm the cameraman, and Group Captain Richard "The Gudgeonmaker" is at the controls.

10/16/2014 Flight Notes:

1. Don't paint the bottom an already low-vis airplane sky blue.....What was I thinking ?
2. The 1050 prop seems to be the best all around. 1060 has better speed. 1070 overheats the motor.
3. Best balance point so far is right at the front of the fins.

StealthStream I Maiden (1 min 43 sec)

Posted by Old_Pilot | Oct 13, 2014 @ 11:34 AM | 1,039 Views
I've had a couple of requests for my spreadsheet that calculates tail volumes based on the mean aerodynamic chord and CG....Spread sheet is in the .zip file and the discussion on the values is in the link below..Vv should not be less than 0.03 and Vh should not be less than .5....that's what's worked for me......

I use AutoCAD to find the MAC and AC's graphically, since I draw all my planes before I build them.....makes it easy to play "what-if"......see example (pdf)

http://www.eaa62.org/technotes/tail.htm (Vv and Vh discussion)
Posted by Old_Pilot | Oct 08, 2014 @ 02:53 PM | 1,036 Views
Gunnery Sergeant Carey Ratcliff at the controls......I'm the camera man...guess what.......I have orders for 3 more

Jetstream III (3 min 9 sec)


Notes:

I'm going to move the fins out another 1/2" each side and enlarge the prop opening to accommodate a 10" prop. Also going to sandwich a piece of 1/16 birch ply to strengthen the nose. Moving the motor to a middle position helps eliminate ballast for balancing. Indicated CG is 1/2" in front of the projected intersection of the trail edge of the KF airfoil. One more thing.....I'm not going to cut off the point of the "cockpit" (which I used for an air inlet), rather I'm going to cut in scoops..(2) in the front facing forward, and (2) exit scoops in the back facing backwards.
Posted by Old_Pilot | Oct 03, 2014 @ 08:36 AM | 2,006 Views
I've been fooling with this for a couple of weeks, trying to figure out how to fit all the pieces on one piece of 30x40 foam board......

30" WS 50% KF "airfoil".........same power plant as the Swept Stik....for now

Also working on a wing core using an S-6061 airfoil......

Whaddy'all think ?
Posted by Old_Pilot | Oct 02, 2014 @ 07:15 AM | 1,565 Views
I revised Jetstream 2.0....based on what I learned from flying Jetstream 2.0.

Motor mount has been strengthened greatly....plywood sandwich with a hardwood block. Motor was raised about 1.5 inches
Added a keel (no I didn't)
Reduced the surface area of the elevons
Revised the pattern for the canopy.....modeled the silly thing as a 3D surface/mesh and then unfolded it.....also canopy is now Depron. I plan to use magnets as hold-down's instead of cutting hatches.
Added a color scheme
Added a dowel to the nose, but that's optional.....

Revision: 10/4/2014.....The canopy adds longitudinal stability (stiffness) along the centerline of the aircraft.......so I'm back to gluing it down and cutting hatches
Also, I moved the fins out 5/16 on each side so that a 9" prop will fit better.

AUW 27 oz......28 oz thrust.....no ballast required
Posted by Old_Pilot | Oct 01, 2014 @ 06:32 PM | 1,551 Views
"those who are about to crash don't know it"
Posted by Old_Pilot | Oct 01, 2014 @ 05:14 PM | 1,514 Views
I've had several requests to post the plans, so here they are....sheets are 24x36 ...3-view is not to scale....didn't annotate the drawings , but 95% of you guys already know what to do....I'm still in the 5% that don't !

Updated Notes:

Turnigy 2836/8 1100 kV 18A max
2100 mah 20C 3s
30A ESC with 5 amp BEC
(2) HS 82MG (R/E) (2) HS 55 (Ailerons)
9060 prop (PZ I think)
She'll fly on a 9x5....

Bent Spar is 3/16x1/2 bass with an aluminum splice (see earlier post)
Thrust blocks are 3/16 Lauan ply inlet into the fuse sides. Firewall is 3/16 foam board sandwiched between (2) pcs of 1/8" ply, the front one being inlet for the thrust blocks, epoxied in place. Most of the glue was foam safe CA. The rest is GG and epoxy.

Wing airfoil is a DF-101, solid pink rigid foam core with spar inlet and epoxied. Ordinates are attached as .txt file. Wing tips are balsa...the whole thing is covered with MonoKote..wing and all !

I've taken the L/G off and put a skid plate in its place.....AUW is down to 27.8 oz and with the 9060 prop, thrust is up to 27.3.....basically 1:1 T/W ratio.....even with the extra weight of the L/G, she only took a few feet to get airborne.....and she glides smoothly....and slowly, as evident by the landing in the video below.

If y'all build her, let me know how she flies, and what changes you made......

Keep your nose up in the turns

C
Posted by Old_Pilot | Oct 01, 2014 @ 01:54 PM | 1,508 Views
First flight jitters were unfounded...she was real close to trim when I launched her the first time.......I think I'll take the landing gear (about 4 oz) off and put a skid plate on the bottom.......also go to a 9060 prop....then I'll up the throws on the ailerons at least one notch.......the rest is fine.

Just took the landing gear off......3.2 oz. 10% of the weight of the aircraft.....now we're down to 27.8 AUW

Some of the guys wanted to know where I got the kit......I borrowed Andy Kunz's answer to a similar question....."Well, the plans are mine, the fuse and feathers came from Art Center (or Dollar Tree), the wings and landing gear from Home Depot, and the rest was salvaged from other aircraft."

Swept Stik Maiden (1 min 23 sec)

Posted by Old_Pilot | Sep 30, 2014 @ 02:03 PM | 1,621 Views
AUW 31 oz

Turnigy 2836/8 1100kV
2100 mah 30 C 3s
9050 prop
HS 55 servos
Pink foam wing core
3/16 PFFB (paper faced foam board) fuse and feathers
Posted by Old_Pilot | Sep 29, 2014 @ 06:51 AM | 1,555 Views
The 2200 kV motor helped immensely, though some initial velocity at launch was required. Best method was to hold her by the top of the fuse and fling her out underhanded at about 30 degrees.....didn't get any video.....but she came back in one piece. 24" WS is not quite enough. Will build another one at Hellberg's design dimensions. A bigger prop would help too.....But she still looked cool coming over the field. Will strengthen the motor mount on the next iteration.
Posted by Old_Pilot | Sep 26, 2014 @ 11:23 AM | 1,240 Views
lots of progress this morning..........decided to do her in silver with markings similar to the F-86...until I tested the OLD piece of silver MonoKote.....oh well, it was only $2.00.......so I used the scraps of what I had leftover from previous builds.
Posted by Old_Pilot | Sep 25, 2014 @ 05:08 PM | 1,448 Views
Sorry the video is so short.....my camera operator dropped my phone.......
had to reduce the elevon throws...but she still flew really well.....

Flew her all afternoon........launch was much easier, and I found that if you pointed up at about 10-15 degrees, throttle up, and just let her go,
she behaved.

Jetstream II Maiden Flight (0 min 42 sec)


I have to rebuild the motor mount system..again....plywood this time
Posted by Old_Pilot | Sep 24, 2014 @ 07:41 AM | 1,528 Views
I've had a couple of requests to publish the plans for this bird......

My notes:

1. Round over the leading edge of the wing.
2. Tab and slot the fins
3. Waterproof (I used (2) coats of clear polycrylic). Water based urethane will work too
4. Add a little up and left to the motor (I used one washer)
5. Maximize the elevon servo throws and add expo for flight
6. Keep your hand out of the prop
7. Canopy pattern is close...trim as required
8. 6mm Depron or 1/4" blue foam would yield a lighter assembly (I didn't have any)...I used 3/16 PFF..Paper Faced Foam board
9. I used tape hinges
10. Jetstream 1.0 balanced about 3/4 " forward of the intersection of the trailing edges of the Klein-Fogleman airfoil. I used a 50% top. Jetstream 2.0 should balance about 1" forward of the same intersection.....the front of the fin terminates along that line.

Canopy hold downs are builders choice.....I glued mine down and cut hatches for internal access

AUW as shown is 27 oz. Wing loading is 7.66 oz/SF

Electrics:

Turnigy 2836/8 1100 kV motor
30A ESC with BEC
HiTec HS 82 MG servos
3s 2100 20C battery

One more thing.. cut in air intakes at the front of the canopy, or add a scoop

Another one more thing......DON'T USE POLYCRYLIC.......BRUSH MARKS !
Posted by Old_Pilot | Sep 23, 2014 @ 04:45 PM | 1,558 Views
30" WS x 34" OAL.....she's a little bigger than Jetstream 1.0. That was based on the abundance of thrust available to me with the motor and prop combo......not going to paint this one.....unnecessary weight. Canopy and fins are a bit larger too. Motor repositioned to amidships and strengthened the motor mount. Control surfaces are now in the prop wash. I'll publish full size patterns as a PDF if anyone is interested.
Posted by Old_Pilot | Sep 20, 2014 @ 05:56 PM | 1,370 Views
Flew the Jetstream this morning and it was quite the experience. Quick and agile do not adequately describe her in flight. Launching her was the most difficult part because of the exposed prop, even though I'd added a "keel" by which to hold her. The biggest flaw in the design is that the control surfaces are not in the prop wash resulting in almost no control until she reached flight speed.... the longest four seconds of my life ! Unfortunately, there is no video. Suffice it to say that I'm going to make several changes. The motor will be moved forward, the control surfaces will be enlarged as will the "canopy". The motor mount will be strengthened too. HS-55 servos will be replaced with HS82-MG's to allow for more throw and increase torque. Exponential can be programmed in to dampen flight commands while still having maximum travel available during launch. An added benefit of moving the motor forward will be to help eliminate the need for nose weight to achieve proper balance.. I had to add 2 oz . I may even add a bit of Tomas Hellberg's simplified thrust vectoring to help with launch.....

Motor: Turnigy 2836/8-1100kV
Prop: APC 8060
Battery: 2100 mah 3S
ESC: 30A
Flight weight: 22 oz
28" WS x 32" OAL
50% Klein Fogelman airfoil
Posted by Old_Pilot | Sep 19, 2014 @ 09:37 AM | 2,061 Views
3/16x1/2 Bass with a piece of 1/16x1/2 x5 aluminum strip, sandwiched, epoxied and riveted. (My father owned a boat company so I've got a gillion aluminum rivets) And it's adjustable.....so long as you don't adjust it too much and work harden the aluminum strip......it'll crack

(4) 3/32" soft aluminum rivets with backing washers.

Solid aluminum spar weighed 2.34 oz....hybrid spar weighs 1.23......
Posted by Old_Pilot | Sep 18, 2014 @ 01:43 PM | 1,308 Views
Since I totaled the Ugly Stik a few days ago, I've been trying to decide whether to build another one just like the first, or something different......decided on something different.....

48 Swept Stik (It was pointed out to me that The Hooker was a 10 degree swept wing version of an Ugly Stik......flight pictures were awesome...hope mine looks that good in the air ) edited 9/20/14

Pink foam wing core, art board fuse and tail feathers, CF spars and a bamboo stiffener in the stab R/E/A/T. May forego the landing gear just to keep the weight down........Cut her out tomorrow....didn't get a chance to fly the Jetstream today...honeydo's
Posted by Old_Pilot | Sep 15, 2014 @ 05:43 PM | 1,323 Views
Have already cut her out.......

Cartwheeled the Stik this morning, like Nadia Comaneci....broke everything except the electrics.....field hadn't been cut due to rain, and I hung the L/G on some taller grass.....she looked like the end of a floor exercise dismount ! Glad I was by myself, 'cause I'd have never heard the end of it from the guys at the field.

Update...should be able to fly her (Jetstream) tomorrow. It'll be interesting to see what the difference in performance is compared to a flat wing ........I used a 50% Kline-Fogelman airfoil.....my first.

She's kind of a cross between a foreshortened SR-71 and a B-2.....
Posted by Old_Pilot | Sep 15, 2014 @ 12:38 PM | 1,542 Views
Flew it this morning....sorta......plenty of watts, not enough kV (1000) for the little prop (5.5x4.75)....always on the edge of stall.....flew like a drunk butterfly

Ordered (2) 2200 kV motors.....should be here Wed.
Posted by Old_Pilot | Sep 11, 2014 @ 11:19 AM | 2,103 Views
Since the combat ship has to wait for smaller components (or a larger airframe) I scaled down the Hellberg Mig 29 to a 24" wingspan and fit the parts to (6) of the 14x18 foam trays .....here's the templates

Cut the decals this morning...

"Stu" has been with me a long time (1975). I did a caricature of one of my superintendents way back when. He's graced a lot of drawings as a "scaled" HIM (Human Interface Model). Most of the time my boss(es) would make me change him to a more ergonomic representation, but he did manage to make it all the way through to "released-for-construction" drawing sets several times, usually causing a chuckle or two.

Used AutoCAD and photo paper....Continue Reading