Staging question

Can the Estes C6-0 be staged to a aerotech D 21-4 ? I know one is black powder and the other composite but I have this urge to send my little Sam-X ( Custom Rockets) towards heaven

pepe said:

Can the Estes C6-0 be staged to a aerotech D 21-4 ? I know one is black powder and the other composite but I have this urge to send my little Sam-X ( Custom Rockets) towards heaven

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Not without something to light the d21. It has to be lit at the head end of the motor and blackpowder charge is not likely to make it to the top nor be enough to light it.

Thanks for the response .I didn't think it would work but I thought I'd check.

What tbone told you is true.

You would have a very low probability of success with your original idea.

You'll need a staging timer from Apogee Components if you want to airstart composite motors...

Later! OL JR

I've heard of guys using small Aerotech SU motors with short delays as boosters to light BP sustainers with their ejection charge. I would guess the composite's ejection charge cap would have to be removed and you would need to tape the motors together. So you could switch your setup and have a D21-4T booster light a C6-7 sustainer.

Now I don't know if this is kosher with NAR or TRA guidelines but I want to say I heard of a TARC group using this technique. I'm sure someone will chime in with the proper info;-)

This would be real simple to do if you can get your hands on a piece of thermalite and Teflon tubing. Both of these used to be common in high power rocketry twenty years ago.

The thermalite needs to be long enough so one end goes completely up to the top of the composite motor while the other end meets up with the top of the black powdered motor. The Teflon tubing needs to be about ¾” of an inch shorter than the Thermalite. Slide the Teflon tubing over the thermalite and then tape the tubing about ½” short from one end of the Thermalite. Stick this end inside and up to the top of the composite motor and then tape the part sticking out of the nozzle so it can’t move. In flight the short exposed end of the Thermalite will be lite by the Black Powder motor. As soon as the burning thermalite hits the Teflon tubing it will jump to the end of the tubing and light the exposed Thermalite inside the motor. This in turn will ignite the composite motor. This whole process will take but a few tenths of a second.

So this is how it can be done, but I don’t know if this would be legal to do these days.

John Boren
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Check out this thread: https://www.rocketryforum.com/showthread.php?46685-AP-to-BP-Staging

The main problem is that you can't depend on the delay time being short enough, and the motor isn't certified anymore if you shorten the delay beyond the manufacturer's minimum (assuming that's it's drillable, which it would not be with a D21). In theory the BP charge should light the sustainer, but there's no guarantee. If you remove the BP charge and try to light the sustainer with just the delay grain, it will NOT light.

marcusSRG said:

I've heard of guys using small Aerotech SU motors with short delays as boosters to light BP sustainers with their ejection charge. I would guess the composite's ejection charge cap would have to be removed and you would need to tape the motors together. So you could switch your setup and have a D21-4T booster light a C6-7 sustainer.

Now I don't know if this is kosher with NAR or TRA guidelines but I want to say I heard of a TARC group using this technique. I'm sure someone will chime in with the proper info;-)

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Just stage to the most poweful Estes D or E motor, if your upper stage will hold that size motor.

cerving said:

Check out this thread: https://www.rocketryforum.com/showthread.php?46685-AP-to-BP-Staging

The main problem is that you can't depend on the delay time being short enough, and the motor isn't certified anymore if you shorten the delay beyond the manufacturer's minimum (assuming that's it's drillable, which it would not be with a D21). In theory the BP charge should light the sustainer, but there's no guarantee. If you remove the BP charge and try to light the sustainer with just the delay grain, it will NOT light.

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Ah, yes! I knew I saw that. I would definitely NOT suggest removing the BP charge, just the cap. But also I don't see why a D21-4 to a C6 wouldn't have a sufficiently short delay in a minimum diameter 18mm two stager...even with a bonus delay on a D21-4, the upward coasting time of a min dia 18mm bird like that would be like 7-10secs (depending on winds) and a bonus delay on a D21-4 likely wouldn't be more than 7-10secs. Either way it's a risky flight, but it sounds fun.

I'll also make note that you could only use a D21's, D10's and 'old style' 24mm SU motors if you were to do this because they have 'flat' forward bulkheads, allowing the motors to be taped together. The new E's with the protruding yellow bulkheads wouldn't work for this...unless you gap staged...which adds more risk as it is.

The old thermalite trick or good 'ole electronics is definitely the most reliable way to go here either way.

JumpJet said:

This would be real simple to do if you can get your hands on a piece of thermalite and Teflon tubing. Both of these used to be common in high power rocketry twenty years ago.

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Great and fun method, but where the heck do you get thermalite these days? Does anybody know?? Anyone?? I've found imitation recipes online but AFAIK it's 100% OOP or at least unavailable to the public. I know it required a LEUP. When I first started flying at club launches back in the late 90's guys were doing this all the time and I've fiddled with it some. Lots of fun and so much easier than a timer....but it is sort of an art. Tom Binford still does it as I recall, unless he's run out of his thermalite stockpile. Care to comment, Tom?

marcusSRG said:

Great and fun method, but where the heck do you get thermalite these days? Does anybody know?? Anyone??

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Um...well you see, I have some. I'll sell it too. How much do you want?

tbonerocketeer said:

Um...well you see, I have some. I'll sell it too. How much do you want?

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I would like....some Check your PM box (unless you read this at exactly 8:09 EST, then wait a few minutes for me to write the message:wink.