Problems with staging
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Were they Estes BP motors? Were they oriented correctly with the nozzles down? Were they butted/taped together or was there a gap between them?
In addition to the questions Antares asked, I note where you said "you can see where the ejection charge charred...". You should be using motors in the lower / first stage that are specifically designed for that purpose, with a "-0" in the motor designation. Those motors will not have an ejection charge...
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What were your motors?
One upper engine with a quest one was an Estes. They were not taped, hard to say if they were actually touching or not but they were at least relatively close to each other I would say within eighth of an inch quarter at the very most
You are really not being clear here, but if the upper one was a quest Q-jet, that's your problem. Those are composite motors that cannot be lit by direct staging from a lower booster motor. Direct staging only works from BP motor to BP motor.
It was an A6 BP motor
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Was the bold text mean to be "question?" The way it reads, people are thinking you were trying to direct-stage Quest composite motors, which is known to not work. Several threads on the topic.
Welcome to the party aa1961. So, you have two 2-stage models, right? Each model had a C11-0 in the booster (1st) stage, correct? One of the models had an A6 in the sustainer (2nd) stage and the other had an unidentified estes motor, right?
Did the A6 look like this?
If so these are out of production Quest motors.
Telling us the name of the kits might be helpful. Pictures are almost always accepted here.
Did the A6 look like this?
If so these are out of production Quest motors.
Telling us the name of the kits might be helpful. Pictures are almost always accepted here.
Unfortunately I don't have pictures that will be a good idea for next problem LOL. One kit was a Comanche 3 using the lower booster. The other one was a custom rockets Galaxy. Both booster motors were c11-0. The quest motor did not look like those but it was probably an old motor just judging by the package and it's definitely BP
Ok so we'll go with Quest old stock in the Comanche 3 sustainer. And C11s in the Galaxy. I always liked that Galaxy: 24mm to 24mm bad motor scooter. Just off the top of my head, one problem that sometimes occurs is that pressure wave at booster burnout separates the stages before the sustainer can light. One workaround is to create a couple of small pressure relief holes around the forward end of the booster. Nothing bigger than 1/8th inch diameter, 180 degrees apart. Another is a small piece of scotch tape to hold the stages together for an extra nano-second to allow the time for the 2nd stage ignition. Hope this helps.
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It sounds like he was trying to use two stages of a Comanche-3 with this combo:
Venting the booster might help as the Quest A6 has a pretty small nozzle throat.
I've never had it happen with a Chinese-made Quest motor, but the other possible failure mode is clay from the nozzle-forming process blocking the propellant at the top of the nozzle. Make sure you can see the black propellant through the nozzle. If you can't, gently spin a 3/32 inch drill bit by hand up through the nozzle. Shake the resulting bits out on your hand and repeat until they come out black.
Clay in the sustainer nozzle like this might be a factor in the C11 to C11 failure.
The Quest motors in @samb's post are even older German-made Quest BP motors. The black/white label Chinese-made ones have been OOP for several years.
Venting the booster might help as the Quest A6 has a pretty small nozzle throat.
I've never had it happen with a Chinese-made Quest motor, but the other possible failure mode is clay from the nozzle-forming process blocking the propellant at the top of the nozzle. Make sure you can see the black propellant through the nozzle. If you can't, gently spin a 3/32 inch drill bit by hand up through the nozzle. Shake the resulting bits out on your hand and repeat until they come out black.
Clay in the sustainer nozzle like this might be a factor in the C11 to C11 failure.
The Quest motors in @samb's post are even older German-made Quest BP motors. The black/white label Chinese-made ones have been OOP for several years.
I can't think of any gap-staged kit that calls for holes in the booster. It could be a YMMV thing IDK. I adopted it as a best practice on advice from club members I fly with. Cheap insurance.
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No the instructions do not call for venting and I don't believe it's not intended to be a gap staging rocket it's just a bit hard to tell how close the motors are once you install the boosterI can't think of any gap-staged kit that calls for holes in the booster. It could be a YMMV thing IDK. I adopted it as a best practice on advice from club members I fly with. Cheap insurance.
Hmmm... curiouser and curiouser. Really would like to see a picture of those.
The Sasha has such venting through the centering rings on the booster motor mount.I can't think of any gap-staged kit that calls for holes in the booster. It could be a YMMV thing IDK. I adopted it as a best practice on advice from club members I fly with. Cheap insurance.
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And the Boosted Bertha. It's been mentioned in another thread that the booster CRs for Sasha and BB are likely the same parts.
Sure I can post a pic what you want a picture of the inside of the booster on both rockets?
I also found with the accessory boosters (Booster-55 and Booster-60) that putting vents in significantly increased their reliability when using C11s rather than D12s. The propellant in a C11-0 fills less than half the casing so there's a fair gap already before you even get to the nozzle of the next stage. I even got John Boren to (grudgingly) agree that it's a good idea to do that.
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Do you put them in the outer wall of the plastic, above the nozzle and below the little paper BT section?
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Since we're on the topic, is there any rule of thumb for the total area of holes to vent a gap staged booster? Like area vs. motor size vs. volume to be vented, or some combination of those and other factors? Or do people just say, "That looks about right to me" and run it?
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As @BEC mentions above, clay in the sustainer motor may be a problem. Sometimes a black powder motor may fail to ignite with an actual igniter. As a precaution, you might ensure that there are no obstructions in the nozzle before you use a motor for a sustainer. Take a very small dia drill bit and lightly twist with your hand inside the nozzle without damaging the nozzle until you get a little bit of black powder to fall out. Doesn’t take much. After a failed ignition you might be able to get that same motor to ignite if you drill down through the charring and get to the fresh powder.
Your staging issue might not be related to this at all, but you might give those failed motors a second try on a single stage launch if they are still in tact.
Your staging issue might not be related to this at all, but you might give those failed motors a second try on a single stage launch if they are still in tact.
Yes and especially the orange and white motors.
Orange and white....like this? This is a German-made A8-3 that I got from Quest early in my BAR period (so a dozen years ago). I didn't know there were any A6-4s like this....
This has become my standard operating procedure for prepping a multi-stage rocket. I even have a 3/32 drill bit epoxied into a 13mm motor case (to use as a handle) in my field box so I can do this at the field if needed to prep a multi-stager.
Yes, in the top of the plastic just above the stager cone. As for size, I don't think they can be too big, functionally. We're dealing with a dynamic and short-lived event. But they can be ugly.
I had a handy tool to hand, a 1/4 inch drill bit mounted in a wooden dowel handle (actually a whole set of these from the late, great ACE R/C) and it was easy to grab it and go. Maybe they're overkill, but they certainly solved the problem.
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