Project date 2002-2006 Completed

Wing Span 12ft

Weight 60-80kg

Engines tested were : 342cc boxer, 500cc boxer, 298cc Wankel Rotary

Max speed achieved was 400kph level flight with 298cc Wankel rotary engine

Launcher also took lot of time to develop

Landing bally or parachute

Autopilot  did with electro-mechanical gyro with gps and pressure sensor. 

Above photo is of final version and videos are from early testing / developing versions.

Takeoff.AVI

Landing.AVI

Views: 1653

Comment by Chuck on September 7, 2011 at 12:40pm

I'm interested in the catapult.

Does it use springs?  Pulleys and Rams?  What makes it go?

 

Thanks

Comment by Ahmed Rehan on September 7, 2011 at 2:24pm

Chuck: catapult is bungee powered. Bungees are pulled by electric winch powered by 24vdc battery it has pulley system to pull the bungees through steel rope. Shuttle has bearing wheels slides over the truss( which is fold-able) for transportation purpose. It has 8 bungee cords folded and secured at one end.   

Comment by Chuck on September 7, 2011 at 3:02pm

Thanks.

I'm trying something smaller.  8 foot long.

Powered by a reverse block and tackle system.  The the sheaves would be forced apart using pneumatic cylinders.  Slack would be taken out of the cable using a second set of cylinders.  I hope to use a computer and proportional pneumatic solonoids to control both the initial shock and to back pressure the rams at the end of the run.  Turning them into shock absorbers to stob the shuttle.

I hope to accelerate 5-10 kilos up to 20-25 mph in 8 feet with low shock.

 

I did a prototype, like you say, using rubber surgical tubing with a pulley system.  And while it launched well it had a huge initial shock which would tear the wings off my larger planes.  But you have the advantage of the length of your launcher.  I do not have the ability to store or transport such a large launcher.

 

Thanks for your info

Comment by Ahmed Rehan on September 8, 2011 at 7:58am

Chuck;

See my video for condor mini uav that launcher is according to your requirement it has only one bungee rope and is 14ft long fold-able. I also worked on pneumatic cylinders but the system is complex and u need power source to fill air cylinder . I used rod-less linear cylinders you will be needing about 10-12 feet cylinder with about 2.5-3 inch dia for 5-10 kilos of load you can add solenoid valve at exit of cylinder to control the shock proportional control is not required. But in the end the simple system is more durable and single bungee launcher uses a hand winch to load.

Bungee is not surgical tube i got the bungees specially made for the launcher they are made of very fine rubber strands  covered by nylon braiding.

 

Yes initial shock is there you have to use aircraft made in composite and wing with good strength spar to resist initial shock.

 

My launcher uses the same bungee to stop shuttle so no shock abbsorbers at the end.

 

Also see the micro-pilot launcher video it seems to be very encouraging.

 

 

Comment by Chuck on September 8, 2011 at 11:34am

I should have something to take pictures of in a month.

 

Comment by avionics on September 9, 2011 at 4:01am
How did you measure your speed?
Comment by Ahmed Rehan on September 9, 2011 at 12:19pm

Avionics: GPS telemetry and also by measuring time from runway end to end.

Comment by Wes Collins on September 9, 2011 at 1:13pm

Would it be possible to mount your launcher system on an LTA drone?  I'm working on a hybrid gas/electric UAV system which combines both lighter-than-air and powered flight drones for a force-multiplying effect.  Basically, is it possible to reverse the launching system and mounts so that they are on the top of the fuselage rather the underside?  Can a remote launching actuator be added to the avionics and flight control package?

Comment by Ahmed Rehan on September 9, 2011 at 1:41pm

Wes Collins:  Can you post the photo of your drone so that i can give you advise remote launching actuator can be added.

 

Comment by Chuck on September 9, 2011 at 2:08pm

If you mean trigger the launch sequence?  Yes. 

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