The original G64 had a single large propellant grain. The motor was revised to have two smaller grains so it could be shipped via USPS without hazmat. I would stick with the values in...
Type: Posts; User: mikec
The original G64 had a single large propellant grain. The motor was revised to have two smaller grains so it could be shipped via USPS without hazmat. I would stick with the values in...
You're right, my mistake. But these don't look inconsistent to me, they both say the G64-7 should have an HDK-20 with a green ring, as does...
The second one you posted wasn't for the hobby line motors (RDK rather than HDK.)
You could really skip the Aeropoxy and use Devcon for the fillets and JB Weld for the retainer. Some kind of filler for the filllets (microballoons or silica) would make it easier to manage.
http://www.apogeerockets.com/Wind_Caused_Instability is a nice discussion and indicates potential problems with relying on rules of thumb too much.
While John says the variance was higher for the #2 screws, I'm not seeing that in his data -- the variance looked like it was about 14% for 3 screws and 16% for 2 screws, which I wouldn't think was a...
I enjoy flying my Maniac on single-use E20 motors, just friction fit with masking tape. It costs about an extra dollar per flight relative to the E18 reload and you don't have to worry about losing...
For the kits, providing the built weight and some indication of motor selection/performance, if not a simulation file, would be helpful.
The kits are a little too stubby for my taste, and...
http://en.wikipedia.org/wiki/Superpressure_balloon
We're talking about the ArduIMU drift correction algorithm. All I am saying is that accelerometers are not useless in planes, just potentially confusing. I think ArduIMU uses heuristics based on...
No, it isn't. When a plane is in level flight, it's being held up by lift and an accelerometer reads 1g from the reaction to the lift force, just as an accelerometer reads 1g sitting on a table....
This project seems to use only accelerometers and no gyros. You can't solve the general guidance problem without gyros because accelerometers can't directly sense gravity.
Try reading this:...
Planes aren't usually in free fall (try walking in an airliner, works fine). That's essentially how ArduIMU drift correction works in level flight.
It doesn't, which is why the whole drift correction method method outlined in that web site doesn't apply to rockets.
The good news is that you only need to control the rocket for a few seconds,...
On a related note, I've noticed that the predicted altitude for V-K nose cones in OR is always lower than the equivalent ogive, which seems like the opposite of what's usually observed. I started...
I've spent a fair amount of time looking at detailed winds aloft predictions from NOAA (see my article in the latest issue of Sport Rocketry) and I haven't found them to be that accurate. It's...
Since you don't really know the winds aloft, this is kind of overkill IMHO. Instead you should angle the rail outward based on the maximum altitude you expect to reach, and a worst-case assumption...
The table in the 1968 Estes catalog (the first year that the motor was called that AFAIK) says that the A8 has a total impulse of 2.5 N-s and a burn duration of 0.42 seconds, making it an A6. ...
I'm not sure, but In the specific case of the A8, it may go all the way back to the metric conversion that happened back in the 60s -- the motor called the A.8 (0.8 lbf-seconds) in the 1967 Estes...
Anything would be better than Blackjack. I had a similar problem with a CTI I175 upper stage (White, which I'd have said was fairly clean), though my camera was closer to the stage than yours. My...
Of course, we don't really know what the effects of heating and aeroloads will be. Mechanical durability at room temperature doesn't count for much here.
My experience is limited to the 38mm and 54mm cones, where the few examples I've seen were slightly asymmetric/out-of-round near the tip. That said, they were quite robust. The vendor states that...
Good point. If you can figure out how to deploy without using pyrotechnics, then using traditional drogueless deploy at apogee and then opening both chutes at a fixed altitude will probably work...
You can set an apogee delay of up to 5 seconds and use apogee for chute 1, then deploy chute 2 at a selected altitude with main, if the rules allow it.
Next year's TARC rules aren't officially out yet, are they? Last year's says "They may use
autonomous onboard control systems to control any aspect of flight as long as these do not involve the...
Some nose cones (typical commercial fiberglass layups) are probably not capable of surviving high mach. I've seen a lot of speculation that FWFG cones have come apart from heat, but I don't think...
You raise an interesting point about nose cone shapes, but I don't think there's a lot of solid evidence that aeroheating is as much of a problem as some have suggested. Most sounding rockets use...
In my experience, the SiRF III chipset is unsuitable for rocket use; the few times I tried one, it lost lock on boost and produced garbage results for the rest of the flight.
There may be...
Amen. Conversely, you can't assume that composites will work any better because they are lighter, but they're definitely harder to analyze than aluminum (speaking as one who's worked on composite...
The 4 and 5.5 inch are still available at http://rocketrywarehouse.com
What does "best" mean? Most scale? If so, the Estes and PR ones have the right fin profile.