ozzie111
Posts: 16
Joined: 12/9/2003
From: Waco,
TX, USA
Status: offline
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vicman,
We built several small test model of the X-30. As I describe all of these models, understand that the scaling factor is based on motor tube diameter. The large X-30 was designed around
a 98mm tube to accomodate a full M motor. The first test vehicles were 29mm. These were
designed specifically for certain flight profiles. we designed 2 for straight boost tests, 1 for
testing our backup parachute recovery system, and 1 for glide testing. The glide test was performed by dropping the aircraft from under one of my large sport .80 powerd R/C planes.
None of these are really good for boost to glide recovery. Our main test vehicle was designed around a 24mm motor tube. This is the model we used for boost to glide trials to determine
proper control throws, and C.G. location. I do not have any proper plans for these models.
The 98 mm model was constructed from CAD drawn plans, but I will be unable to provide a copy of these plans. Sorry. It is kind of expensive to fly at $350 per flight, and thats if you
already own the M motor case.
I am however working on some CAD plans of a vehicle that will be based on a 38mm motor
tube. This model will fly on G motors, and be AMA legal since G motors are considered model
rocket motors. You will have to be patient with me on these though. My CAD skills are a little
less than fast. I will post here when I have the plans completed. I am also considering a laser
cut kit if there were a demand.
Another great flying large rocket glider is the Aerotech Phoenix. It is really an advanced build
but a great design. They can sometimes be found on ebay.
John,
One thing that I have found with rocket gliders is that they really need to have symmetrical airfoils, and be set up zero-zero for boost.
What I usually do is set up my landing/flap trim on my transmitter so when I boost everything is zero-zero, and once I reach apogge I hit the switch to glide trim. This is like putting reflex
into the airfoil. That is what we did on the X-30. If you think flying a rocket glider is a kick in the pants, try recovering from an inverted boost behind you. Don't ask how I know.
As far as motor placement, it is best to have it as close to center line, and on the C.G. as possible. I think it is better to have the motor above the centerline, than below it.
If you can put it on the G.C. it is easier because you don't have to worry about trim changes.
One problem we had to overcome with the X-30 was that the C.G moved back as the fuel burned. That is exactly the opposite of what you want. It's no fun going unstable on boost.
Again, don't ask how I know.
On another note, The Firebat that Great Planes sells can be converted to a reasonable rocket glider or 29mm motors. If anyone is interested in how to do this conversion, let me know.
Oz
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All Forums >> Radios, Batteries, Clubhouse and more >> Unusual R/C >> RE: My Rocket Plane 
RE: My Rocket Plane - 
I don't want to get too radical with the larger or hybrid motor stuff just because of the price. however I have no prob with G size and under. I have been wanting a good rc rocket glider project, however the only plans that have been offered are for the estes Astro Blaster which I just had plotted and am getting ready to build. I would love to get a set for that F-14 in the previous posts but have not gotten a response. It would be nice to give a Lady Hawk a whirl, having learned RC on the old Dave Brown 
