XolveJohn
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It is a rudder only RC BG for B4-2 or C6-3 motors. There is an article on it in the May/June Sport Rocketry for 2017.
I don't use the Spektrum "brick" radio, but the Turnigy 5X, with the rcvr board out of the case, and put on a plate with an indoor flier tiny servo. Radio system is $25, servo $4.50, battery $2, charger $10. Kit price is $25, without radio eqpt. Contact
xolvejohn
@
gmail.com
Here is some intro data and pics:
If building kit for free flight use (no radio control), it is best to fly with B4-2, as use of C6-3 will be hard to recover, especially in ANY wind. Trim to circle.
If building kit for radio control, you will also need the following items:
-Turnigy 5X radio system (includes rcvr) Hobbyking.com 9331000002-0
-HK linear servo “ “ HK3D-1.7L or 1.7R
-Turnigy lithium cell “ “ N160.1S.25
-E-Flite USB charger E-Flite EFLC1008 (various venders)
Building the radio module requires fine soldering skills, if unable to do, contact me for possible availability of pre-built radio module.
Background
In 1969, Bob Singer designed the BumbleBee 1/2A boost glider, to beat the Competition Model Rockets (Howard Kuhn) Manta, a type of delta flying wing. With its low aspect ratio wing giving better boost altitude than “sailplane” wing gliders, it succeeded, turning in 2 minute glides.
The RumbleBee-C is a 4X upscaled version, with rudder only RC, and a VECTOR POD which offers enhanced reliability. Tilting the fixed pod down by 2.5 degrees offsets the “down moment” of the normal thrust line, to ensure straight boost. The motor module is ejected with a streamer, providing CG shift for glide trim. This is actually how the first front engine BG’s worked. I find it lighter and more reliable than pop pods.
RC boost gliders have a reputation of being hard to fly. FAI S8 RG’s can be, due to marginal boost stability. The only CG shift comes from propellant burn-off, with some up elevator at apogee providing the trim adjustment for glide. Boost can be a terror, because the elevator must be constantly “jinked” to provide vertical flight. Beginners often just loop them into the ground.
The RumbleBee will boost straight on its own. Having zero incidence (no up elevator), it will still transition and glide well (CG must be correct). Some say auto-elevators or slight incidence is required on BG’s, but as long as the stabilizer is LOWER than the wing, turbulence off the wing will provide some push down on the stabilizer (ref. G. Harry Stine). I have never seen a death dive with this glider. Using rudder only control makes this bird easy to fly. Elevator control is not really necessary.
I don't use the Spektrum "brick" radio, but the Turnigy 5X, with the rcvr board out of the case, and put on a plate with an indoor flier tiny servo. Radio system is $25, servo $4.50, battery $2, charger $10. Kit price is $25, without radio eqpt. Contact
xolvejohn
@
gmail.com
Here is some intro data and pics:
If building kit for free flight use (no radio control), it is best to fly with B4-2, as use of C6-3 will be hard to recover, especially in ANY wind. Trim to circle.
If building kit for radio control, you will also need the following items:
-Turnigy 5X radio system (includes rcvr) Hobbyking.com 9331000002-0
-HK linear servo “ “ HK3D-1.7L or 1.7R
-Turnigy lithium cell “ “ N160.1S.25
-E-Flite USB charger E-Flite EFLC1008 (various venders)
Building the radio module requires fine soldering skills, if unable to do, contact me for possible availability of pre-built radio module.
Background
In 1969, Bob Singer designed the BumbleBee 1/2A boost glider, to beat the Competition Model Rockets (Howard Kuhn) Manta, a type of delta flying wing. With its low aspect ratio wing giving better boost altitude than “sailplane” wing gliders, it succeeded, turning in 2 minute glides.
The RumbleBee-C is a 4X upscaled version, with rudder only RC, and a VECTOR POD which offers enhanced reliability. Tilting the fixed pod down by 2.5 degrees offsets the “down moment” of the normal thrust line, to ensure straight boost. The motor module is ejected with a streamer, providing CG shift for glide trim. This is actually how the first front engine BG’s worked. I find it lighter and more reliable than pop pods.
RC boost gliders have a reputation of being hard to fly. FAI S8 RG’s can be, due to marginal boost stability. The only CG shift comes from propellant burn-off, with some up elevator at apogee providing the trim adjustment for glide. Boost can be a terror, because the elevator must be constantly “jinked” to provide vertical flight. Beginners often just loop them into the ground.
The RumbleBee will boost straight on its own. Having zero incidence (no up elevator), it will still transition and glide well (CG must be correct). Some say auto-elevators or slight incidence is required on BG’s, but as long as the stabilizer is LOWER than the wing, turbulence off the wing will provide some push down on the stabilizer (ref. G. Harry Stine). I have never seen a death dive with this glider. Using rudder only control makes this bird easy to fly. Elevator control is not really necessary.