Now all is needed is a simple solid state guidance system.

I've got one, at least an anti-roll system that I've been working on for quite some time. I've still ground testing but it looks very robust and reliable. I plan on doing some test flight this spring and summer.

Doug

Check out Sparkfun electronics.

Ken

Sparkfun has a 9DOF board - 3axis accelerometer, 3 axis rate gyros and 3 axis Magnetic (compass). That plus an Arduino or other small micro-controller and servo-controlled fin tabs might make a dandy little project. The only weakness is the accelerometer Z axis is only 6 G's or so. Survivability is in the 10,000G+ range though so you could fly it even if you didn't get full accel data. The also have a nice selection of other sensors so adding baro and an high-G Z axis accelerometer might be a nice addition. It would be interesting to see what kind of data stream you could get from the rate gyros and magnetic sensor in terms of roll and absolute roll position.

The interesting part of this to me is that you'll have to characterize the sensor data (regardless of what type of sensors you use) with multiple flights just logging data to figure out how to interpret the data well before attempting a control algorithm. An interesting project - there is some open source UAV code out there that might be adaptable to this, at least for a deeper understanding of the issues. If someone buys the sensor, I have several Arduino boards and would love to look at at least doing a datalogger.

I've been thinking about this for a while as well. I have some micro servos that I've been playing around with for a gimbaled motor system.

Warren as you point out, you would need a lot of flights to characterize this. I’m thinking a small version based on the relatively long burning E9 would be the way to go.

I have been working with this little beastie with the intention of hooking it to generic data logger, which will make it into a rocket eventually. http://www.sparkfun.com/products/9156

Sadly it has not gotten much attention, got in over my head with clockwork over the winter. I'll dig out the code, and if I manage to get it into shareable shape, I'll post for anybody interested. Its straight C with some libs... avr-gcc toolchain. Might have been faster to prototype with Arduino toolchain, i just cant stand that silly editor thingy and haven't been bothered to pull the guts out so that it will build properly from regular makefile or Ant or something.

+/-16Gs on the sensor is a little scant, but I am not a particular fan rockets which perform instant translation from pad to apogee, so I think it will be ok. IIRC, I picked that sensor after looking at the boost G graph in Adrian's article on Violent Agreement, max 25G in a minimum diameter 38mm. Though in retrospect, its a very heavy 38mm being a three stager, so I might have choosen poorly. ( http://www.rocketryplanet.com/content/view/3087/38/ )

I have been working with this little beastie with the intention of hooking it to generic data logger, which will make it into a rocket eventually. http://www.sparkfun.com/products/9156

Sadly it has not gotten much attention, got in over my head with clockwork over the winter. I'll dig out the code, and if I manage to get it into shareable shape, I'll post for anybody interested. Its straight C with some libs... avr-gcc toolchain. Might have been faster to prototype with Arduino toolchain, i just cant stand that silly editor thingy and haven't been bothered to pull the guts out so that it will build properly from regular makefile or Ant or something.

+/-16Gs on the sensor is a little scant, but I am not a particular fan rockets which perform instant translation from pad to apogee, so I think it will be ok. IIRC, I picked that sensor after looking at the boost G graph in Adrian's article on Violent Agreement, max 25G in a minimum diameter 38mm. Though in retrospect, its a very heavy 38mm being a three stager, so I might have choosen poorly. ( http://www.rocketryplanet.com/content/view/3087/38/ )

Sparkfun has some gyros, too, that could make the task easier. That's what Frank Hermes used, I think in his new Rocket TiltMeter:

http://www.rocketryplanet.com/index.php?option=com_content&task=view&id=3590&Itemid=29

I have an Arduino coded to use a 6 DOF breakout and two small HiTec servos for pitch and yaw. Larry Haynes and I are working on a prototype gimbaling system that will utilize either a long-burn Aerotech E6 or G12 R/C motor. Should be ready for testing in a few weeks.

Back around 1971, I took a large Centuri Little Joe II, made for an Estes "D" motor, made a payload bay extending from the nose cone into the body tube. I mounted a 4" diameter toy gyroscope in it with a string coming out of the side. No fins on this bird. When we were ready to launch, we started the countdown and at about t-5, we pulled the string as hard and as fast as we could and then ran backwards so we could get away and observe. It wobbled a little after it left the launch rod and then stabilized and flew straight as an arrow. With that experience, could you not gimbal a gyro with control rods that go down to vains mounted at the end of the exhaust nozzle to help stabilize and do it like polaris, poseidon, and trident missiles are stabilized. I have drawn up the mechanics and it seems fairly easy. It is not on my top ten list right now, but is on the list as the current list gets shorter. You could even have the gimbals from the gyro work servo motors for working fins tabs or vanes, it would seem.

An all-mechanical solution would be cool in a retro way.

My own project that may come up to the front burner sometime this season is a GPS-based, self-returning rocket. I have a cheap RC paraglider canopy on order that should be good for a mid-powered rocket. I would set up the rocket so that it gets deployed out a side hatch and hang horizontally from the chute. A microcontroller would control steering servos based on GPS location to return the rocket to the pad on the way down, or at least as close as the wind will allow.

Tthat is a neat idea!. I can easily imagine hinged payload doors similar to the STS. The ejection charge is set off, the doors open, and the parasail comes out. The shape of the sail could be altered, as the Wright Brothers altered the shape of their wings and use that to steer the bird home. You could also place a homing beacon in the back of your truck with the hatch open and have it land there. So much easier. Then there is no recovery. Close the hatch and drive off. LOL.
I have also finished making my first payload bay with my Raven mounted in it and using one of the switches I won at the club meeting in January. Your components sure are slick. I showed my grand-son when I powered it up and he was really surprised. Looking forward to hooking it up to my lap-top and using the FIP, and practicing with it. I have made a small low pressure chamber for testing my e-bays to see if I have them programmed properly. Nothing fancy and it is not instrumented to tell me simulated altitude, yet! It seems to do the job, though.

When fin allignment is not perfect, the wind is a bit strong, and you want to keep the nose up during the coast phase........

There has to be some pirated IC plans for enhanced flight control systems...some where...with all the miniaturization/mass/microgyro production...where's a mass produced shipping container full of them? A cheapo chinese made to order cast in resin, nosecone weight with rechargable lithium batteries, 8 wires comming off...gps included... rejects from obsolete stores of antiquated surface to air missiles meant to satisfy world demand for the high power model rocket guidance on, windy dazes, and coast phase "ERGC" (Enhanced Rocket Guidance Control)...is it Aerocon that has them?... http://aeroconsystems.com/cart/ and paraglide rc recovery right back to me....Then I can keep my well lipidized gluteus firmily planted in in my parasol shaded servo powered portable dentists chair/multipal cup holdered/snack bag arm,complete with telescope flat screen real time fore/aft camera for the ultimate in sport rocketry flying/viewing

Eager, Dan W

There are several RC airplane products that have GPS-based "return to home" functions that work with the aircraft servos. Getting the mechanical part right is the hard part for rockets. I'm starting to lean toward a deployed wing + low altitude chute instead of a steered chute, because ram air parachutes have fairly limited capability to penetrate a headwind. It would be cool to launch to 10 kft in 15 mph winds and have the rocket come zipping back to near the flight line before popping a landing chute.

What do you think for the fin tab servo control???

http://www.futaba-rc.com/gyros/futm0830.html

http://www.futaba-rc.com/gyros/futm0807.html

I am hopeful...A retired designer/engineer contractor for NASA...also a model train buff I met here at Caboose hobbies suggested this......