HyperSpeed
Well-Known Member
- Joined
- Jan 21, 2009
- Messages
- 117
- Reaction score
- 8
For some time now I have held onto the idea of a return-to-home, GPS-aided recovery system for one of my high-altitude projects such as a boosted-dart. As time moves forward, the feasibility of such a system increases as component costs to build the system decreases. I feel component technologies are well within the realm of practical ability to allow a return-to-home rocket to have great odds to succeed at this time. It still is a highly conceptual plan, though. Generally, I start highly conceptual plans on TRF as discussions to see if I can then make the leap to a functioning project which will benefit other flyers forever, or erase the idea completely if the persuasions convince me there is little to be gained by other flyers. Hopefully it's not one of these ideas: 
I'm still a fan of conventional recovery methods, don't get me wrong; main parachutes will stay and tracking via LTE won't hurt a thing. But, rockets are going to return-to-home on their own given enough evolutionary hobby time, so I'm choosing to start trying now.
Anyways, let's get to the general concepts I have personally targeted as potential methods:
1. Deployable delta-wings, glider-style wings, or 'sponsons'
2. Deployable arms with motors+rotors/props A.K.A. a rocket-body drone, on the way down
3. Deployable Z-axis-centered collective pitch swashplate rotor A.K.A helicopter autorotation recovery
For method number 1, a large recovery stage of flight becomes effectively a "cruise rocket", referring to the idea that the aerodynamics would resemble a cruise missile (hold your stones). While I consider this an effective method of return in theory, I only imagine it effective while actively piloted by a human. Bad thoughts occur when I picture a hobby-grade flight computer landing a fragile object with high horizontal speed when things such as trees, tall grass, or rocky boulder-laced terrain becomes involved. I move to the next methods because of these reasons.
Method number 2 instills much similar ideas as method number 3; I picture much better landing outcomes regardless of terrain types with decreased horizontal velocities. Method 2 done properly would likely yield some of the slowest vertical decent velocities as well. However, being a powered decent method, weights increase along with costs.
I arrive through deductions of flight complexities that method number 3 could hold some merit as a rocket recovery method. Helicopters are able to build up kinetic energy in the main rotor via blade pitching, which can then be expelled as lifting energy near touchdown by pitching the blades into a lifting position, to slow touchdown velocity. Technically, a parachute of the proper type could use a swashplate to help return home (without the rotor), but I see less likelihood of a flight system handling those dynamics very well.
The main issues I see to initially test method number 3 primarily arise from the required stabilizing body size to prevent the rocket from spinning about the Z-axis instead of building rotor inertia. This is of course why helicopters have a tail. The good news is that the tail doesn't need to endure high air speeds, and as such could be rather lightweight to produce the required drag on the way down.
The question I'd like to ask is, has anyone witnessed an RC helicopter of rather large size autorotate without using tail power and tail pitch--just drag alone? I think this becomes one of the first problems to address in order to create a test setup method and take the idea further along.
I'm still a fan of conventional recovery methods, don't get me wrong; main parachutes will stay and tracking via LTE won't hurt a thing. But, rockets are going to return-to-home on their own given enough evolutionary hobby time, so I'm choosing to start trying now.
Anyways, let's get to the general concepts I have personally targeted as potential methods:
1. Deployable delta-wings, glider-style wings, or 'sponsons'
2. Deployable arms with motors+rotors/props A.K.A. a rocket-body drone, on the way down
3. Deployable Z-axis-centered collective pitch swashplate rotor A.K.A helicopter autorotation recovery
For method number 1, a large recovery stage of flight becomes effectively a "cruise rocket", referring to the idea that the aerodynamics would resemble a cruise missile (hold your stones). While I consider this an effective method of return in theory, I only imagine it effective while actively piloted by a human. Bad thoughts occur when I picture a hobby-grade flight computer landing a fragile object with high horizontal speed when things such as trees, tall grass, or rocky boulder-laced terrain becomes involved. I move to the next methods because of these reasons.
Method number 2 instills much similar ideas as method number 3; I picture much better landing outcomes regardless of terrain types with decreased horizontal velocities. Method 2 done properly would likely yield some of the slowest vertical decent velocities as well. However, being a powered decent method, weights increase along with costs.
I arrive through deductions of flight complexities that method number 3 could hold some merit as a rocket recovery method. Helicopters are able to build up kinetic energy in the main rotor via blade pitching, which can then be expelled as lifting energy near touchdown by pitching the blades into a lifting position, to slow touchdown velocity. Technically, a parachute of the proper type could use a swashplate to help return home (without the rotor), but I see less likelihood of a flight system handling those dynamics very well.
The main issues I see to initially test method number 3 primarily arise from the required stabilizing body size to prevent the rocket from spinning about the Z-axis instead of building rotor inertia. This is of course why helicopters have a tail. The good news is that the tail doesn't need to endure high air speeds, and as such could be rather lightweight to produce the required drag on the way down.
The question I'd like to ask is, has anyone witnessed an RC helicopter of rather large size autorotate without using tail power and tail pitch--just drag alone? I think this becomes one of the first problems to address in order to create a test setup method and take the idea further along.
