Al_M
Member
A little off-topic: can you fly a D-powered booster coupled to a B or C sustainer?
Yes, no problem. Estes has done it in some kits.A little off-topic: can you fly a D-powered booster coupled to a B or C sustainer?
There is no NAR rule against that, that I am aware of. Yes, you do need to know what you are doing. Still, the word of the local RSO is god.I agree with the last 2 posts concerning Composites and Delays : Apogee Rockets says basically the same thing on their website. Engine-to-engine staging is pretty much a "Black Powder Thing" and not something Composites are even designed to do since they ignite and burn differently. As far as time-delay motors in the booster, I "think" there even might be a NAR rule against that (at least in Low Power - which is all I do and pretty much all I know about) for safety reasons since any delay invites tilting-before-igniting the 2nd or later stages at least, and possibly reaching apogee first and heading downward before igniting the next stage at worst.
It is not and should not be standard practice, but it does have its uses. When done properly it is just as safe as zero delay staging. Delayed staging may be less reliable, but neither is 100%. A staging failure will result in a prang, so you should aim your rocket to land in the center of a clear recovery area, in the event of a staging failure.I haven't heard much about folks using non-zero delay motors to ignite an upper stage. An ejection charge is much more energetic than the burn-through you get from a -0 BP motor, is it really safe and effective? Here, by "safe", I mean "safe for the rocket".
Also, 4 seconds is a pretty long coast between stages of a low-powered rocket. Would need to be very to sim and confirm that the upper stage would light with sufficient velocity, otherwise good chance of cruise-missiling.
That is not true, although the ideal way would be to have a flight computer electronically ignite the sustainer at the optimal conditions.The other way around (1st stage BP, 2nd stage composite) would require electronically triggered ignition of the composite sustainer motor.
If you are not familiar with delayed staging, you should dread the reports of Tom Keuchler in the old NAR Tech Review.
I certainly do dread them.... but I would also like to read them. Are they available anywhere?Are they really that bad?
I'm sorry about the "d". Have you tried NARTS? You also might try old issues of The Model Rocketeer.I certainly do dread them.... but I would also like to read them. Are they available anywhere?
A black powder booster motor has no ejection charge at all.
Enter it into Rocksim or OpenRocket to evaluate stability.Because I searched "staging" and ended up here so I thought I'd ask...
I'm adding a third stage to one of my Estes Sashas and I'm wondering about stability.
The CG moves aft about the same distance of the length of the booster when the second stage is added. I'm guessing that boosters cannot be added indefinately as soon the airframe will be mostly fins.
I will assume that some area will be added to the nose and I'm thinking of a coupler for a temporary nose extension and perhaps even some extra weight also.
Any tips regarding CG (or anything) are appreciated.
An E12-0/E12-0/E12-6 in a Sasha should be a show.
Thanks.
I did find the referenced info on the Apogee and Estes websites after I posted my initial question. Obviously for LPR, things really haven't changed at all, and I'll just need to experiment with the fit of everything next time I fly this one. As old as it is, I may just keep it on the shelf and find something more easily replaceable for messing around with 2-stage flight... or better yet, design my own.
Cheers!
A little off-topic: can you fly a D-powered booster coupled to a B or C sustainer?
...with the caveat that the Mongoose booster usually streamlines in, so you want to be sure that it's aimed downrange when you fly it.
Definitely add NC weight. The third stage should get the rocket to orbit or maybe to the ISS.Because I searched "staging" and ended up here so I thought I'd ask...
I'm adding a third stage to one of my Estes Sashas and I'm wondering about stability.
The CG moves aft about the same distance of the length of the booster when the second stage is added. I'm guessing that boosters cannot be added indefinately as soon the airframe will be mostly fins.
I will assume that some area will be added to the nose and I'm thinking of a coupler for a temporary nose extension and perhaps even some extra weight also.
Any tips regarding CG (or anything) are appreciated.
An E12-0/E12-0/E12-6 in a Sasha should be a show.
Thanks.
It's all about maintaining proper CG/CP relationship. Stages add more weight in the rear, oftentimes larger fins are needed to compensate. Simulating in OR or Rocksim will tell the tale.When you add a third stage to a two-stage rocket, is it advantageous to make the fins on the third stage larger than those on the second stage?
Is there a disadvantage to making them smaller?
I would first check the rated total max lift off weight for the first booster, not a hard and fast enough rule, but if you are near or nearly beyond that limit, then you need to do a more accurate check and be more cautious in light winds when launching a marginally too heavy rocket. Speed off the rod is the critical performance measure there to ensure the fins have enough airspeed to serve their function.Maybe I can get to Hawaii
So, tandemming motors. What works and does not work with the newer Estes motors, Say an E12-0+C6-7, etc. Asking for a fiend.Many times you can just put a C motor into the top hole of a D12-0 motor. Back in the 70's before a certain person complained about this practice in Competition, we glued the two motors together to gain extra thrust from the empty D motor. I flew a few of those in competition in when it still was allowed. IN Fact the NAR newsletters at the time had articles and MATH on how it worked so well... They also had articles by very famous early 70's competition people on how removing the ejection charge from a B-2 motor allowed delayed staging to extra altitude for competition.
Edit: Just found the old memory cell location for what that was called, "Tandem Motor", if you don't glue it , it is still NFPA legal
A number of altimeters are now available for electronic staging of model rockets, that will fit in 18/24mm tubes, there's even one that fits in a 13mm tube.
Yes, please. If I could stage Q-Jet or Aerotech Ds in a very small tube, I’d be a very happy man indeed.This sounds interesting. We have an Altus Metrum Easy Timer, but it is for a 24mm tube.
Could you please share what specific staging altimeters/timers will fit in 13mm and 18mm tubes?
Enter your email address to join: