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rockets

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first question is, could you fly a Estes F15-0 to a AT H135W?
The other question is how big of a motor can you fly in a 2 stage rocket without needing electronics?
I am hoping to fly a mid-power 2 stage rocket or maybe even a high-powered 2 stage rocket without electronics. I'm on a budget.
THANKS!
 
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dhbarr

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It is possible, though not trivial, to stage from AP to BP. f15 staged to h135 is dangerous nonsense.

Launch some BP. Launch some AP. Stage some BP. Figure out why AP delays don't come shorter than 4-5 secs.

If you haven't the funds for electronic staging, you're going to come up short on electronic tracking as well; you lose your airframe.
 

rockets

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It is possible, though not trivial, to stage from AP to BP. f15 staged to h135 is dangerous nonsense.

Launch some BP. Launch some AP. Stage some BP. Figure out why AP delays don't come shorter than 4-5 secs.

If you haven't the funds for electronic staging, you're going to come up short on electronic tracking as well; you lose your airframe.
Does Aero-Tech or CTI make motors without a delay?
 

blackbrandt

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Hey... kinda sounds like a blackbrandt 1.0.... :p
 

Zeus-cat

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Does Aero-Tech or CTI make motors without a delay?
If you don't want to use motor eject on an Aerotech motor you simply leave out the powder and plug the ejection charge well. If you mean do they make a motor that behaves like an Estes F15-0, then the answer is no. You can't stage AP motors like you do Estes BP motors. You must electronically ignite an upper stage AP motor.
 

Handeman

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What he said.
The reason Estes motors work for staging is the combustion chamber is inside the end burning BP. When it has burned close to the top of the grain, the grain fails and the internal motor pressure is vented through the ruptured top of the grain. This throws lots of chunks of burning BP forward and since it only takes one little piece to hit the BP near the nozzle of the upper stage motor to light it, that works quite well and is relatively dependable.

APCP motors have a central core and burn from the center of the motor to the sides. That central core extends all the way to the top of the motor. To light an APCP motor, you have to light it at the top of the grains, not the bottom near the nozzle. So not only can you not light an APCP motor the way you do a BP motor, it doesn't have the open top and bursting combustion chamber like an end burning BP motor does.

The reason for the 4 second minimum ejection delay on APCP motors is to prevent an ejection event while the motor is burning, you must have enough delay material in place to be structurally sound enough to handle the internal motor pressure. You don't want the motor pressure to burst the delay grain and ignite the ejection charge while the motor is still burning. When that internal pressure drops off at motor burnout, the remaining delay material that is thick enough to hold in the burning pressure takes 4 seconds or so to burn through at low pressure.

So, as Zeus-cat said, you must electronically ignite an upper stage AP motor.
 

mwtoelle

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The F15-0 booster is marginal even on the Pro Series II E2X Rockets if there is more than a slight breeze. I definitely wouldn't use one in with a sustainer powered by the H135 that you suggested. As others on this thread have said, a composite upper stage requires on onboard electronic staging system for successful ignition.

If you really want to fly a two staged mid-power with Estes F15s, I would try scratch building a lightweight rocket designed for those motors using BT-60, BT-70, or BT-80 sized tubing to keep the weight down.
 
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swatkat

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Staging F to H would also be Level 1 High Power and you'd need the associated launch field dimension requirements and distance back from the pad. Electronic ignition has gotten a lot cheaper and simpler with modern devices, but an F15-0 booster cannot lift a lot of weight, you'd be looking at something like a 6-7Oz sustainer stage with the H-motor + F BP +booster taking up a minimum of 9-10 Oz. With that weight, you'd want electronics for recovery as well, assuming you are planning on recovering it!
 

Bat-mite

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The Estes F15 has an average thrust of 14.4 Newtons. The E16 has an average thrust of 16.0 Newtons, so you would be better off with the E16. The F15 can safely lift 10.2 ounces, whereas the E16 can safely lift 11.4 ounces.

Why not try an E16-0 to an F15-x? The Estes PSII-EX kits are great for that. They even sell a booster stage for them. Cheap, too! Use the 40% off coupon at Hobby Lobby.
 

shreadvector

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I was asked a few questions about multi-staging at the last launch, so here is some info that I posted to our NAR Section's YahooGroup:

Estes Technical Manual (see pages 11 and 12):
https://www2.estesrockets.com/pdf/2819_Estes_Model_Rocketry_Technical_Manual.pdf

Estes Classic Collection of Technical Reports (see Technical Report TR-2, “Multi-Staging”):
https://www2.estesrockets.com/pdf/2845_Classic_Collection_TR-TN.pdf

Excellent video of NARAM R&D report:
https://youtu.be/1Nhe5Y78PRQ

And the Apogee Components "How 2-Stage Rockets Work" web page:
https://www.apogeerockets.com/Tech/How_2-Stage_Rockets_Work
 

Charles_McG

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Here's a link to a video we made this weekend. It's a scratch built BT60 based two stage. 29mm F15 to E16-8.

With motors, tracker and chute tender, we were at 440g. 3:1 thrust to weight. Which should cap launching to a 4mph wind. It was 13mph. In retrospect, not safe. But it flew to 1538'.

[video=youtube;Q7Q83zL3cgA]https://www.youtube.com/watch?v=Q7Q83zL3cgA[/video]
 
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