My two cents worth. Probably worth about that.
NAR Safety Code:
This isn't law, but it's much more than a bunch of cute rules for the little kids who don't know better or know more. This code (and the High Power one) were worked out over time by true experts as a way to codify best practices in rocketry in a straightforward form. It's a good way to protect rocketeers, the public, and our great hobby. Plenty of rocketeers aren't NAR or Tripoli members but still folow the same safety codes because they make so much sense. There
are laws governing safety aspects, giving regulation powers to the FAA, local Fire Marshals, and the BATFE, to name the main ones.
Arming:
Your first posts described and showed the unit with very short leads to the pad. Turning one's back and crouching wouldn't be enough to make that safe. As you've stated, the system (or a remote arming/power switch) can be positioned the specified (yeah, by the codes) distance away from the pad for that amount and configuration of total impulse, and it should be. That's an easy solution to that part.
Unexpected Firing;
I think one of the posts on this one got missed or misunderstood. The poster gave a scenario where a radio launcher like this one could be unsafe. It went like this.
- The controller is turned off
- The igniters are hooked up.
- The controller is turned on from 15 (or 30, or whatever) feet away.
- The rocketeer walks out to his chosen launch point 250 feet away.
- While he walks, the pad tips over, and a stray radio signal causes a launch while the pad is in this position.
That's a valid concern. Even if the pad doesn't tip over, a plane could enter the area, and the rocketeer might not be able to hold up the launch (again, due to a spurious signal), as he easily could if holding a wired remote.
Controls:
Joy sticks, even spring loaded ones, don't make good launch switches, in my opinion, as they can easily be activated by bumping your arm, dropping the remote, etc.
Encoded Signals:
I'm an electrical engineer, and I personally wouldn't be comfortable with an unencoded radio control system. If one was in use, I'd fly elsewhere or at a different time. I've heard too many stories about the problems they can have, and I understand the engineering reasons why. Depending on the environment, one might get away with it most of the time, but it would be a cumulative risk that would reach out and bite, to one degree or another, eventually.
Ideas For Simple Modifications To Increase Safety:
I'd do the following if I was committed to using an unencoded radio remote.
- Definitely use a long wire (as you described) to arm the receiver.
- Use the clearest legal and proper band I could find for my area, even if it costs more.
- I'd look into using a garage door opener circuit or some similar thing to get digital coding, or I'd roll my own. (OK, I'm a EE. That one wouldn't be in the simple category in general.)
- The control has two channels. I'd either set it up so that both channels had to be activated (in opposite directions, to make accidental activation harder).
-OR-
- Use one channel as a way to cause a remote deactivation (servo pulls an arming pin out, etc.). That way if a plane shows up or the pad tips over, you hit the deactivate switch, and nothing can cause it to launch until the rocketeer goes back to the pad and fixes things. The arming circuit could activate a relay latch, and the disarm could break that connection via another relay, thus necessitating a physical return to the pad. Plenty of options here. The key is that once the disarm signal is invoked, no radio signal can re-arm the receiver.
- Using something besides the joysticks to control the signal. Remotes can be dropped, and inevitably eventually will. Kids will do it just about every time. A shrouded or recessed button is better.
- You want an arming pin or similar on the remote controller too.
Safety is paramount. It trumps coolness, convenience, and everything else.
OK. You may conclude that it's worth what you paid for it,
but that's my two cents worth.
As others have stated, no-one wants to get anyone's goat or toss wet blankets, but sharing information on technique, usage histories, and most importantly, safety, is what the forum's all about. As I tell my family, "Safety is part of the skill." I get a kick out of engineering systems that perform in safe and predictable ways, knowing the reasons why, and honing my skills through practice and through other hobbyists who share their knowledge and experiences with me. I'm neither the most experienced person here nor the least, so I can learn and share at the same time.
That, and the sheer pleasant camaraderie, are what bring me back to the Forum again and again, and I think that's the case for most of the people here.
Welcome to the club. I think you're going to like it.
