Does anyone know why the Aerotech Hybrid AP grains(54mm), have a paper liner on the core side, or inside diameter, like the paper liner that the all solid fuel grains have on the Outside Diameter.
New Member
Does anyone know why the Aerotech Hybrid AP grains(54mm), have a paper liner on the core side, or inside diameter, like the paper liner that the all solid fuel grains have on the Outside Diameter.
still have all my fingers
Never flew one myself, but I believe that the paper IS the fuel. I heard rumors of guys making their own fuel grains using very tightly wrapped newspaper.
Thinks before building.
They are entirely made of super-dense paper, or so says the instruction manuals on their website. That's a pretty cool way to recycle and fly for nearly free, though: newspaper.
2013 impulse burned: 5205.1 Ns
2013 impulse lined up to burn: ~56,445 Ns
Member
The topic is the versions that do have two or more grains of APCP. (62.5 grams each) My favorite was the J260 but they haven't been manufactured for over ten years.Originally Posted by CarVac
Besides the J260 there was a J390 with a few more APCP grains and a Turbo K that was all APCP. I never used one of the K's but I watched 5 used in one rocket at the 1996 Heart of Texas launch. Aerotech borrowed my hardware for that one so maybe I could say I have flown one.
As to why there was paper lining the core, I don't know. It obviously delayed ignition of that surface of the APCP but what purpose that served is a mystery to me.
New Member
I never flew one but from memory the aerotech hybrids used a pyro based valve to release the Nitrous. I guess it's possible the paper liner on the core is to prevent ignition of the APCP grain(s) prior to the valve fully opening and decomposing the N20.
If the preheater grain failed to ignite or failed to release the N20 but the grains ignited, you would be in trouble.
New Member
I have one of these motors and 3 or 4 of the reloads. Just last night pulled them out and asked my son to figure out how that all worked. As we looked at it it seems the paper liner would inhibit the AP grains giving the starter grain and pyrovalve time to "come up". They are very cool motors but have lots of parts to them. Would like to see or get my hands on the M motor they made.
hybrid user
The Kosdon by Aerotech K700F has a paper core liner.
Karl Baumheckel
TRA 11594 L3
Lifetime Member
Not what they mean. The core of the K700 is bare propellant, not inhibited in any way.
Dan Patell
TRA 10904 L3
2013 Flights: 8
2013 Ns: 7,609
hybrid user
I have a KBA K700 with a paper core liner in my box right now. I was a bit suprised myself.
Karl Baumheckel
TRA 11594 L3
Member
That does sound uniqe and intetesting . Do you have a way of taking a picture of the motor ?
Senior Member
I saw Hybrid33 fly three of the J390's in a cluster last weekend at the Nebraska Heat Launch.
The AT M845HW is a 98mm L952W reload with Nitrous fed through it. Of course you need the fwd closure, black powder pellet, plastic seal disk and preheater grain to complete the motor.
Bill Richardson ENC USNR Ret.
TRA 8703 L3
It is my opinion that stupidity should be painful, very painful. If it was I think there would be less of it in the world today.
Thinks before building.
What on earth is the nitrous supposed to do, if there's already the oxidizer from the White Lightning? I'd understand if it were Black Jack or something...
2013 impulse burned: 5205.1 Ns
2013 impulse lined up to burn: ~56,445 Ns
Lifetime Member
Please take a few pictures and post a new thread. This is intriguing.
Dan Patell
TRA 10904 L3
2013 Flights: 8
2013 Ns: 7,609
Member
There is never enough AP in the mix so the nitrous reacts with the incompletely burned fuel.
Member
Hi Bill,
I still have that Aerotech M load and complete hardware, would like to use it, but bummed out by the thought I could never use it again.
Kent/GLR
Member
I have the hardware and a reload as well. They can be frown at a TRA Research launch.
John
New Member
Kent
As Bill said Use the L952W reload, this gives you the liner, o rings, top seal ring, and the two fuel grains, buy the J350W reload for the preheater grains and liner for those, I have a supply of the stainless AN washers and the teflon to make the seal disks, a print for the nozzle which I think is just a matter of opening up the L952 throat. All you need to make is the black powder pellet using a mold, black powder, and epoxy.
New Member
Ok I buy the safety need to inhibit the lighting of the APCP grains. Now that leads to the next question, If this was deemed necessary for the 54mm motor why did the M845HW use the same grains as the K458W-L952W-M1419W-1939W-I have sealed boxes with these Grains and all these Motor designations on the label of the boxes, including the M845HW.I have flown the M1419 and have an open L952 and they do not have the paper liners.
Member
According to the list published in Sport Rocketry they are still certified.
New Member
If I remember right the 54mm came out before the 98mm, maybe they found inhibiting the grains was not needed. Or perhaps there is another reason for the paper cores. production related???
Wander if it is still listed on the TRA list?
(:)(:)
It is. http://tripoli.org/CertifiedMMotors/...6/Default.aspx Just a couple down from the top.
Member
Mr. 33 and Sailor Bill,
You boys just made my Christmas card list, thank you for the information! Rumor has it that I have a rather sizeable supply of the actual Aerotech "Pyro-valves" on hand. Mr. 33, please give me a call so I can purchase the stainless washer and Teflon disk from you. Thank you, Thank you!
Kent/GLR
620-727-0045
Senior Member
One of the local guy did his L3 on one. I do not recall if it was inhibited but it came up to thrust REALLLLY fast.
Mark
Obsessed with Rocketry
I like to watch fast flights, but on a cert, I like low and slow. I have not seen a lot of fast hybrids.
-----------------------
Chuck Haislip
NAR/Tripoli Level 3
Level 1 - LOC Minie Magg; Level 2 - PR Broken Arrow;
Level 3 - 10 inch Nike Smoke
Ns for Year: 0 on hiatus serving our GREAT country in Kuwait
My rockets usually fly naked. If they survive, they earn their paint.
Come fly with ROSCO or ICBM in Orangeburg SC => http://rocketrysouthcarolina.com
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