JimJarvis50
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That was what I was planning on doing.
Yeah I was going to put the timer there.
I don't know what a zipperless coupler is..
That was something else I could do if it doesn't fit in in between the fins.
May I see how you do it just so I have all this info in (mostly) one place?
Which ones do this?
How would I use rocksim to simulate separation? I know there is the ignition delay that I can use for the sustainer, but that doesn't seem to work the way I thought it did. That being said, I was planning on separation 0.1s after MECO and then ignite the sustainer 3s later.
Yeah I figured it wasn't to difficult, I have worked with accelerometers before.
What type of equipment will I need for RDF? Is it expensive? And would GPS be cheaper? If so I might sacrifice some reliability, as long as it can get me in the general area (I might put one of these on board: https://www.apogeerockets.com/Electronics_Payloads/Rocket_Locators/Transolve_BeepX , or make something similar)
I'd rather use fiberglass. I'm a little more familiar with it. Also if I go too light I might break the waiver. I'm going to use 22k as a goal and if simulations go too far below that when I have almost everything configured correctly, then I may consider dropping some weight.
As for dual deploy, the booster after staging sims to 4.5k. That's already higher than anything I've ever launched (that will change by the time I build this). It was going to be dual deploy from a single bay with the electronics in the coupler, using the cable cutter method.
Thank you for your very comprehensive response.
Here is a link to a description of the concept.
https://www.info-central.org/?article=132
Simply, the coupler between the fin section and the drogue section is attached to the fin section (in model rockets, it's the other way around). This isn't a two-stage thing - it's just (IMO) how conventional dual deploy should be implemented. The idea is to attach the drogue about 1/3 of the way from the fin section. At the apogee event, the top section gets blown forward but does not change direction. The fin section, however, has to flip 180 degrees. By eliminating the tube from the piece that changes direction, you eliminate the chance for zippers. The 1/3 thing keeps the fin section from continuing forward and crashing into the upper section. Rockets built this way last longer.
Now, imagine that in your zipperless coupler, you have a bulkhead on the bottom and a removable bulkhead on the top. Presto, a spot to put your electronics. These bulkheads would be connected with a piece of all thread, and the recovery harness would be attached to the all thread.
One of my sustainers is pictured below. It has the zipperless coupler, but I don't put the electronics there. Instead, I put them in the ebay and run breakwires, which are attached at the top of the zipperless coupler. You can see the wires in the pic.
I don't have a good example of a shunt to show you. Conceptually, imagine your altimeter outputs and the two wires going to your sustainer ignitor. Somewhere on that circuit should be a resistor - perhaps 1+ watts and 3-5 ohms - but this depends on your battery and electronics. Now, imagine a second set of leads from the same altimeter outputs, but the leads go to a switch. This circuit is the shunt. If the altimeter fires with the switch closed, the current goes through the low-resistance shunt circuit rather than the ignitor, and you don't get fried. The problem is that a small portion of the current will still pass through the ignitor ematch. Thus, you want to keep the shunt resistance low (use short, heavier wires) and the ignitor resistance higher (use the resistor to raise the resistance of that part of the circuit). This lowers the current going through the ematch so that the ignitor won't fire in the event that the altimeter fires.
I believe the modified eggwhatever, the Raven, the RRC3 and the Telewhatever are capable of this. I used to do it with an ARTS II combined with a timer and transistor switch.
I'm no RockSim expert, but what I do is manipulate the ejection and ignition delays. For your example, 0.1 and 3 seconds, I believe you would set the ejection delay at 0.1 seconds and the ignition delay at 2.9 seconds. I often use an ejection delay of 0.5 seconds, although I have a flight planned where I want the parts to coast together for 12 seconds (to slow down) before I separate them. That's what I mean about controlling the flight profile.
Worked with accelerometers??? Not part of the plan.
RDF is a whole nuther subject. If you're on a budget, find a friend with a receiver and furnish your own transmitter. I use BigRedBees in the nose cone and also Marshall transmitters, but there is Walston and several others. Lots of info on the forum on that topic. Sonic beepers don't help much if you're several miles out.
Cable cutter for the booster would be fine. Regarding the altitude of the booster, my bet is it won't go as high as you think. Once the sustainer leaves, it's like putting out the air brake.
Jim