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Archive for October, 2014
Posted by Old_Pilot | Oct 31, 2014 @ 10:27 AM | 5,297 Views
I gave up on the CF 105 Arrow after several attempts to get the EDF mounted......came back into the house, sat down at the computer and came up with this......another morph of the Jetstream....

I'll post the drawings and patterns if anyone is interested.

why I gave up on the 105...I fired up the EDF and it wouldn't stay in the bulkheads....nothing seemed to want to stick to the plastic housing of the EDF....'course, watching the motor go through the front of the aircraft in mid-flight might be worth a look or two....or.....once!

Here's the drawing and the patterns.....thanks Rick !

Update 11/5/2014: fitting out and bench testing this morning....and everything was going fine until I heard "CLUNK" and all the fan blades exited the rear of the aircraft and imbedded themselves in the foam backstop I'd set up.....so, two more hatches in the bottom of the fuse and a new impellor. good to go !

Update: 11/7/2014........Too much weight and not enough thrust....and now I have a Concorde....so I eliminated the lower fuse, added another fan and stuck them to the side of the fuse...added a little bit of wing and got the elevons in the jet stream....Continue Reading
Posted by Old_Pilot | Oct 23, 2014 @ 01:36 PM | 5,005 Views
Three more to build...next week

Added 3/8 sq balsa to front of wing and sanded to the shape of a leading edge.

Update: 10/28/2014

APCE 9050 prop

Golden Power 2217/6 1500 kV...

No. of Cells: 2 - 3 Li-Poly
Kv: 1500 RPM/V
Max Efficiency: 80%
Max Efficiency Current: 8 - 22A (>70%)
Load Current: 1.6A @10V
Resistance: 0.100 ohms
Max Current: 28A for 60S
Max Watts: 311W for 60S
Weight: 70g / 2.45 oz.
Size: 27.5 mm x 30 mm
Shaft Diameter: 4mm

Buddy RC

Posted by Old_Pilot | Oct 21, 2014 @ 07:10 AM | 5,100 Views
Preliminary plans and parts for an easy Avro CF-105 Arrow......3/16" PFF and a little balsa (nose). I'll build and fly her sometime next week.....revise and annotate the drawings then.
Foam blanks are 30x40 printed on 36x48 paper. 3-View is not to scale

32" WS x 40" OAL
50% KF airfoil

64mm EDF - 4400 kV
HiTec HS 82 MG servos
3000 mah 30C 3S

Update: I'm going to add a 3/8 sq balsa stick to the front of the wing and sand to shape a leading edge....same thing for the Stealth Stream

Added color scheme......will print the markings

Update....EDF didn't want to stay put when I fired it up........nothing wanted to stick to the EDF housing and the bulkheads
Posted by Old_Pilot | Oct 14, 2014 @ 07:25 AM | 5,318 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 | 4,486 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 | 4,562 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)


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 | 6,068 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 | 4,658 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 | 4,548 Views
"those who are about to crash don't know it"
Posted by Old_Pilot | Oct 01, 2014 @ 05:14 PM | 4,461 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

Posted by Old_Pilot | Oct 01, 2014 @ 01:54 PM | 4,416 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)