Posted by Jacob Gargano on January 3, 2011 at 12:20pm
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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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.
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!
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.
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.
I just placed a order for a new Projet MQ-9 Reaper 98" and would like some feedback on what parts should I get for it as for as the size servos, motor, esc, etc? and anything else that you'll can assist me with on this build.. Thanks
I have put a E-Flite Power 46 Brushless Outrunner Motor on mine. Haven't flown it yet, but I am hoping it can handle it. FYI - It fits perfectly in the airframe.
I am using a eflite park 480 1100kva and a apc 9x7.5e prop with a 3s 2200 lipo and get 25 min+ flight. nitroplanes video mentions it for about 2 seconds.
Replies
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.
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.
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.
Hi All,
I just placed a order for a new Projet MQ-9 Reaper 98" and would like some feedback on what parts should I get for it as for as the size servos, motor, esc, etc? and anything else that you'll can assist me with on this build.. Thanks
I have put a E-Flite Power 46 Brushless Outrunner Motor on mine. Haven't flown it yet, but I am hoping it can handle it. FYI - It fits perfectly in the airframe.
I will use it for fpv with eagletree system osd and data recorder.
just got it and just have a few flights to get used to how it handels, built as per directions no mods.