I have recently purchased this model plane, in hopes to convert to something a little more than just the average 100m piece of junk.  I'm curious as to what would be the best way to power this to keep it in the air for the maximum amount of time.  Does anyone have any clue, since the model refers to know specific powerhouse.

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Recently completed 5 successful test flights on my MQ-9. 6th flight wasn't pretty..... Just a note to everyone planning to build one of these with the objective of actually flying it.  The wing loading is about the same as a fighter plane model, not a glider or even a sport plane, as it may appear.  The biggest single fault with this model is the wing construction. It is not strong enough to support the aircraft properly in flight without additional reinforcement to keep it from bending. Mine assumed a curved shape with about 1 inch of upward deflection which did not go away after landing.... This also led to a slight twist which resulted in wash-in, not the desired wash-out needed to prevent unwanted tip-stall. The model apparently tip-stalled and crashed due to this condition. I suggest that you remove the bottom covering from the wings and add a strip of carbon fiber to keep the wing from bending in flight. If it stays bent 1 inch from straight after a flight, what must it be doing in-flight? The fuselage took a direct hit to nose upon crashing, but only the first 8-10 inches were ruined. Haven't been able to find any replace parts for this model. Great fit and finish and could make a great flyer if wing issue can be addressed. A little more chord width in the wing to get the loading down would work wonders.

This is what happens when a maker tries to copy the actual aircraft too closely.  Thanks for your input and advice.

Hi, just wanted to know if yours is the 1st or 2nd version?

is yours the first or second version?

 

  I noticed the wing deflection problems and even though they came out with a second version of the MQ-9 98 inch wingspan, I modified it.  See: http://botmite.com/html/lgear_-3.asp  Essentially, carbon fiber struts adding less than an ounce to the Predator weight were made to grab the newly added homebrew CF rod running through the wings.  You can see the build for yourself: about 7.5 inches long.  So, instead of a hardpoint attachment of the strut the rod is attached making a much larger wing connection.

Fast forward to October 2013 - I decided to completely re-engineer the wings to something substantial.  So, the new wingspan is 10 feet, rectangle geometry, 10 inch chord.  Other tweaks include a slight camber and a thickness adjustment.  Calcs show a 1600 feet per minute ROC, or better, depending on flying weight.  Much more weight can be flown, hence with more batteries a much longer flying time is possible. 

Flight time is a function of energy consumed.  With a 750 watt 900 rpm/volt electric motor, 100 Amp ESC, 10 Amps 10.1 V power - flying lower and slower brings more flight time with bigger wings and larger flight envelope.  Doing the calculations yields much information in terms of altitude, time aloft, battery power and more...Happy flying!

http://botmite.com

http://www.analyticalmind.org/aviation/aircraft-aerodynamic-design

I experienced an early crash in testing - wound up rebuilding it with Carbon Fiber reinforcement ... the resulting structure slightly increased weight but greatly enhanced strength and stiffness.

MQ-9 Reaper is the basis for the Botmite build - a radical overhaul. 

Botmite 1.1 wings were changed to deal with the MQ-9 98" (8 foot wingspan) for a number of important reasons.  The lift of the 510 sq. inch stock MQ-9 was not adequate after modifications.  So, a 1 foot chord and tapered foot on either side now provides 1,080 square inches in plan view built over styrafoam core connected by dual CF (carbon fiber pultruded pipe) to the fuselage. 

This reduced the risk of (wing) tip stall, lowered the stall speed - depends on flying weight.  Given a Clark-Y - CL 1.5 max, the lift and drag increased.  At 10 pounds, it will fly at 35 mph, 0 degrees alpha, no flaps. Now it climbs from 3,000 fpm to over 5,000 fpm really light ~ 8 pounds.  Flight mechanics now demonstrate up to about 20 g's of centrifugal force with the reinforced fuselage ~ also CF reinforced.  Now this model airplane can outperform some of the IMU electronics. 

A 900 k or 900 rpm/Volt motor rated 850 watts or roughly about 1 BHP provides thrust with a 100 Amp controller.  In level flight, very little hp is required to fly this plane. 

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