CONGRATULATIONS AGAIN 2004 USA TEAM LEADER!!!!!
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The original plan for the intermediate size airframe pictured here was for it to look like the small "OJ" model.
Two and a quarter ounce engine complete with engine mount, muffler, etc., and "less than optimum" structure and materials resulted in an inordinately long nose on my smaller intermediate size stunter. In the future this size airplane will have 3.5 ounce engines and construction concepts very similar to my latest flying art aircraft that is now finished and is being flight tested and trimmed for optimum book-pattern performance for camcorder documentation purposes.
After concept confirming flight tests are completed and documented all relevant data will be published. The much more preferred socially responsible smaller airplane that is so practical to use with kids is to be an eighty (80) percent scaled down version of my new bird.
This slightly modified Thunder Tiger .07 engine generates as much power as my most hopped up Tee Dee [THIS HAS PROVEN TO BE WRONG–please see comments near the middle of this caption] but far more cost effectively and quietly at a cost of only a little more than a half ounce. Because my hopped up Tee Dees blow so much fuel through them necessitating more than the half ounce difference, for most of a flight the Thunder Tiger .07 powered stunter is actually lighter for all but almost the very end of a flight.
The .07 works really great on my "number one R" running 21k with an APC 5.7x3 prop. I get nice comfortable patterns flying 5 second laps on 51 feet of 20 lb test FIRELINE. Engine up thrust in clockwise upright flight is 4 degrees, P–factor rudder has 6 square inches, the wing leading edge was rounded to approximately a 3/32 inch radius back in the late '80s when we vainly tried to get massive .10s to work on "R." A strip of 1/8 balsa was added to the leading edge of the elevator to aerodynamically balance the stabilator precisely on the hinge line. Full size plans for the original "R" are available from MODEL AVIATION magazine, plan number 480. The heavier .07 used to balance the airplane between the two center of gravity points shown on the plans makes the nose over one inch shorter than the original.
At this point in the .07 engine's settling in process I am using 18 percent nitro and approximately 28 percent oil–2 percent Amsoil (see note at end of paragraph) mixed with 9 percent Klotz Benol which is then mixed with a blend of fuels to bring the nitro content up to the desired percentage. The engine is peaked out on the ground for about 45 seconds and then set at a rich 19–20k which settles into a very nice 21k in the air. By simply using large fuel line tubing there is now no need for a forward bladder–the wing mounted tank is adequate. The forward bladder concept is now being used on my very efficient .109 (in mild weather) powered 747 Myth Buster. AMSOIL note -- The oil used in all tests that uses AMSOIL is the original 2-cycle oil that I still have in abundance. No tests have been made with AMSOIL'S newer formulations.
That stock muffler in the above picture weighs as much as my modified .10 muffler. Twenty gage wire and JB Weld® works great on exhaust systems.
My now standard practice/demonstration flying procedure is to first put up a few pleasant nostalgic flights with the .07 powered "R" and then fly the monster Myth Buster. When I am finally satisfied with the level of flying performance the flights will be video taped to document the fact that virtually perfect book–patterns can be flown. By that time I hope progress will be made on making the rule book standards geometrically possible. Harmony with observable reality could make STUNT a really great activity.
Like the .10s the .07 generates significantly more drag than a Tee Dee .049. This is not a problem for mild weather flying but in turbulent conditions more speed is needed than what has been obtainable so far, especially in hot 90 degree plus weather conditions.
Okay, there is good news and bad news about the .07. The good news is that the .07 is a really great sport engine that runs so well on bladder pressure that a separate fuel tank for throttle control will not be necessary for throttle control aerobatic flying fun. The bad news is that it must be hopped up to satisfy my power requirements. I really thought there was more power available in the stock engine than turns out to be the case, sorry.
With the carburetor venturi "DREMELlED" out to 5/32 inch diameter, the sleeve raised to 174 degrees exhaust timing, and the top of the sleeve ground down to enable a proper compression ratio to be obtained, I have high hopes that the .07 will run as efficiently on a tuned pipe as my .109 does. A quarter of a horse would be nice. Restricted back to around .22 bhp could also give us a very nice low noise level.
So far the "magic formula" for the .07 seems to be between an APC 5.7x3 at 21k plus rpm and a Tornado Magnum 5x3 (or equivalent load) at 25k rpm. I reduced the exhaust timing to 160 degrees to get a full wave tuned pipe to work well. Got lots of experimenting to do.
In 80 plus degree weather, at 25k rpm a 5.5x2 APC prop runs beautifully with the exhaust restricted full wave tuned pipe .07 generating 90 db from 9 feet across my concrete patio. I am really excited about my hopped up .07. It produces more power on the same amount of fuel that is significantly lower in nitro content than it does in stock condition, however, the higher nitro formula is needed for steady running performance.
Okay, the latest data looks very much like what we need. A 5.7x3 cut down to 5.2 inches runs very close to 24.9k rpms for 6.5 minutes on 50 ccs of 22 percent nitro and approximately 24 percent oil in 80 degree weather. If my data and assumptions are correct this time, the .07 is generating almost .23 bhp under these conditions.
Recently discovered information suggests that the above horse power data may be a little low. "R" now flies better than ever using the very steady running 5.2x3 prop mentioned above. I added a streamlining shroud/heatsink behind the engine cylinder that is now significantly more powerful, steadier running, and more efficient than any Tee Dee I have ever owned. I am so excited about full wave tuned pipe technology that I have already set up a Max .10 for the very same treatment as the .07.
I replaced the ram air filter with one I thought would provide more intake muffling and proceeded to put up a flight with R. It would not stay on the engine so I flew with no air filter system at all. Fuel consumption was up 17 percent and rpms were down nearly 1k. Interestingly, the dandy little bird flew 50 to 51 mph in gusty 10 mph wind with a little rain and it really felt great everywhere in the pattern. For mild weather deadly accurate flying I will be using drag streamers to knock the speed down to around 44 mph.
My thermometer was reading 100 degrees in the shade provided by my flight support equipment both before and after my very steady running .07 powered R put up a convincing pattern at 50 mph. The wind was so gusty that it flipped my 747 over on its back while the plane was stationary on the asphalt. The good news is that the hopped up .07 is proving to be a perfect stunt engine. The bad news is that I can't get a .109 to work in hot weather.
Okay, cutting the 7 x 3 APC prop to 6.4 inches makes the .109 usable in temperatures up around 90° Fahrenheit. More rudder power is now needed to trim out wobble on the 747.
Not so fast Mumford! (punch line of the favorite funny story of my dear friend Doug on the east coast who can be contacted from the web site located at: http://www.biblequest.org/ – Doug's new computer technology is not easily compatible with my web tv system, so in order for "older technology users" to enjoy the kind of character building material that is now much more in style than it was before the recent election ('04) please click: http://www.hebronlanechurch.com
http://www.biblework.com
http://www.truthmagazine.com
http://www.watchmanmag.com
http://www.reasonforhope.org ) My .109s are now for use only as teaching aids. The full wave tuned pipe modified Max .10 is working very well now in 90 degree plus temperatures. The .10 requires significantly less nitro than the .07 to run well in hot weather.
Replacing the bellcrank and horn with larger music wire, fine tuning engine thrust line for equal inside and outside turns, and moving the c.g. back to within one half inch of the whip powered position has tamed the 747. The challenge to tune this beast for perfect book–pattern flying is irresistible!
9/3/04 – The new larger 4.5–1 differential bellcrank and doubling of the original rudder area now allows the big ship to balance right on the "whip powered center of gravity point." With finesse sharp corners without wobble can now be flown. Adding still more rudder power should allow even sharper "smooth" corners. This new aeronautical realm has an unexpected quantum leap in performance possibilities that simply must be explored!
9/7/04 – Okay, next entry will be after camcorder documentation of what is now finally performing as advertized.
Please check out: SHOCK AND AWE STUNT INVITATIONAL
Address:http://community-2.webtv.net/RICHARDPORTER3/SHOCKANDAWESTUNT/
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TESTING SETUP
The longer nose than planned on this plane does give us a little more to see in the air. Notice the large angle of the tip drag streamer as the plane flies through a high "g" corner while flying a full pattern on a 20 foot radius circle (when my arm is extended). The "SOUND LEVEL METER" shown in the upper right side of the screen is reading about 81 db from about 30 feet from the plane. The video tape audio recorded weather info from my trusty "Weather Station," and the calibration markers on both the near and far side of the circle makes it easy to precisely check the turn radius and weather conditions even in "shifty" winds.
CORNERING FROM THE OTHER DIRECTION
This shot shows the far side calibration markers better. The stunter is over one marker and the other one can be seen by the "5." With such short lines it is best to place the markers directly across the circle for the most accurate measurements. The stake in the center of the circle is used to keep my control handle very close to the center for maximum measuring accuracy.
WHOOPS!
I had to step back quickly to avoid hitting the calibration marker on landing.
Smaller real control–line precision aerobatics airplanes can be a lot of fun to fly in demonstrations on short lines. Flying performance looks a lot like that of whip powered flying which has become my preferred modeling promoting approach.
MY FAVORIATE INTERMEDIATE SIZE STUNTERS
The newest one incorporates all of the latest technology recommended for both size airplanes. Building tips will be added to the site as time and opportunity permits. A close up of the shirt gift given to me by my computer friend Bernie can be seen a little better at the end of this site. At the present time my very favorite mission with my "impossible" planes is to interest kids in modeling/SCIENCE (Bias against scientific thinking in modeling is a formidable but vincible challenge! For example, though the problems with the square maneuvers are now old enough to "vote," see: ''BLACKBALL BALL'' http://community-2.webtv.net/RICHARDPORTER/BLACKBALLBALL/page2.html, they will be fixed.) I owe my very existence on the web to my buddy John at Sky Sport Hobby Shop (ad. on hat). I enjoy giving him some advertising when I am having fun with planes.
With all the angles and curves, "bending" the nose area out slightly, and the relatively small prop, the engine offset is not a serious esthetic problem. A recent modeling enthusiast did not notice the engine offset on my "747" even after observing a number of takeoffs and landings. I had to point it out to him.
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