Hey Guys.

Discussion - Plazma Whizzz: rocket assist wing

Background:
So, a number of us buddies have been messing with the Whizzz (from Zebrahobby.ca) for a few years. It was initially designed by Henry from Zebra for a direct drive GWS IPS 50. I am happy to say that most of us tried that power system. We then unanimously acknowledged that IPS 50 and Testosterone do not go hand in hand. So, we moved up to a Johnson brushed and of course soon afterwards our rewound hot CD Roms and 3S. As of today, we have clocked the Whizzz at 132km/hr on a radar gun, and have one buddy using an Arc Inrunner that surpasses that by 35 km/hr.

Anyway, that is all cool and nice, but not why we are here today.

Today:

So, I decided to mess around with a little "controlled" fire by slowly and progressively adding increased powered Estes Rockets. OK, maybe not progressive power...but it was slow as we waited until any fire hazard was "Low". I recently decided that the Whizzz needed 20:1 thrust to wieght ratio. It was only able to achieve that with four C-6-0 Estes rockets. As it turns out, these were the specs:

Plane: Whizzz flying wing
AUW: 10.8 Oz
Power: CD Rom on this airframe (127 km/hr recorded speed)
Battery: 3S Apogee 800
Servos: 2 Pico BB
ESC: CC Pheonix 10
Ignitor: Dimension Engineering-Pico Switch
Assist: 4 C-6-0 rockets (1.8 seconds of 13.6 'peak' pounds thrust)


Anyway, Henry made a great hand-tosh launch and the Pico Switch worked flawlessly. The problem was that in the higher quality video you can see the Whizzz role over left and dig its own smokey little grave.

Buddy-Luke had to get in his last "digs" about visual recognition of the final downed location...Luke, "You Blaster"



http://www.rcgroups.com/forums/showt...57#post5676166

Now thats a lawn dart!!

You ever watch mythbusters on Discovery channel?? They have always had problems with simultanious ignition of rocket motors.. Every time they have problems.. That probably what your problem was.. one rocket ignighting before the others...

Chris

Originally Posted by Scoobyvroom

You ever watch mythbusters on Discovery channel?? They have always had problems with simultanious ignition of rocket motors.. Every time they have problems.. That probably what your problem was.. one rocket ignighting before the others...

Chris

Actually Scoob, I think what my problem was... not enough rockets.

Kidding aside, I agree that milliseconds of differential thrust variance likely caused the role-over. But having said that, we never took it too seriously (except safety precautions).

If you try again... point straight up just as you hit the ignition of the rockets...

and it may be a good idea to do a test-flight or two firing A or B size rockets to adjust thrust line of the rockets. Any one rocket motor igniting should result in straight flight. Then all firing at once will resutl in straight flight. (if the model is able to take the acceleration)

I plan to do a rocket assist glider, air launched, one C series on each side, in Lear Jet style pods and sequential ignition for longer total burn time. Test flights will involve A and B series to get the thrust lines right (Estes makes adapters that will allow this... intended for test launches of rockets, before putting in the full power size "cartridge") for the small offset from centerline.

Oh my god, a Canadian WMD! Watch out guys, we may have to invade, I mean liberate you!

Do it again, do it again.

Mike

how do u start the rockets when the plane is flying?

tax... fairly simple really... ESC and 9 volts or higher.

Reminds me of a story I heard, years ago, of a dude's remote activated missles(mounted under his plane's wing)........one of them accidently fired in the pit and hit another plane!

I tried rockets on my Easystar. Still needs a little tweaking. I use a switch that sets my rockets off.

Video's at www.rcflights.co.uk

Mark