AeroTech Open Thread

[AeroTech]

Hello. I made a post in the HPR forum about machining down the aft closure thrust ring OD to match the motor tube OD and someone linked me to this post.

https://www.rocketryforum.com/threads/aerotech-open-thread.125657/post-2044762

My desire is to use the motor as part of my interstage for a 2 stage project so the motor would be sticking out of the back of the sustainer by X inches in order to fit into the booster coupler. Can you confirm whether or not machining down the aft closure thrust ring in order to match the motor tube OD would constitute an experimental motor?

We will be making flush aft closures available soon. Machining down hardware not recommended.

 

[mtnmanak]

View attachment 642389View attachment 642390


Gotta say…getting the smoke grain liner out of a 75mm forward closure is a real PITA. Anyone have any ideas to make this a little easier then how I do it? This was a L1940 reload BTW….

+1 to @rfjustin 's suggestion of using more grease when you assemble the motor. I grease the ever loving snot out of the entire well. I subscribe to the theory that there is no such thing as too much grease in your smoke grain well. After the flight, if you use a lot of grease on the sides and bottom of the well, the liner will just pop out easily and, I find, that the well is much easier to clean because the burned residue does not stick to the greased metal. Wipe it out with a wet wipe and clean it thoroughly when you get home.

 

[DAllen]

+1 to @rfjustin 's suggestion of using more grease when you assemble the motor. I grease the ever loving snot out of the entire well. I subscribe to the theory that there is no such thing as too much grease in your smoke grain well. After the flight, if you use a lot of grease on the sides and bottom of the well, the liner will just pop out easily and, I find, that the well is much easier to clean because the burned residue does not stick to the greased metal. Wipe it out with a wet wipe and clean it thoroughly when you get home.

Agreed. Can't hurt so next time I load one of these bad boys up I'll grease it up. Grease is cheap.

 

[beeblebrox]

I ran into an issue last weekend where I had to sand three SU Aerotech motors with integral thrust rings in order to fit them in a cluster mount. Reload casings work fine since the thrust rings have two gaps 180 degrees apart, I guess for using a wrench or something. I wish that all single use motors had the same thing, two "flat spots" in the thrust ring on opposite sides of the case.

Those two flat spots you refer to are to fit the AeroTech motor hook in all standard AeroTech kits.. I.E. Mustang, Initiator, Arcas, etc.... The standard SU motors and their corresponding reload cases are the same length except for the aft closure. This only refers to the model rocket Aerotech reloadables, not the HPR/ISP reloadables...

 

[mtnmanak]

Agreed. Can't hurt so next time I load one of these bad boys up I'll grease it up. Grease is cheap.

Real rocketeers do it greasy! Go greasy or go home! Is that grease on your rocket or are you just happy to see me?

(I'm here all week, folks. Don't forget to tip your waiter.)

 

[khabuda]

If you are new to all of this, then how are you doing all of this?

By researching on the Internet and asking questions directly to the manufacturer.

 

[Joekeyo]

It would be nice if the nozzle cap/forward closure cap/powder holder was made out of a material that was clear or translucent. That way you can see if the powder is going into that tiny hole. It's a great invention. I'm just trying to make the best better.

 

[Banzai88]

It would be nice if the nozzle cap/forward closure cap/powder holder was made out of a material that was clear or translucent. That way you can see if the powder is going into that tiny hole. It's a great invention. I'm just trying to make the best better.

https://en.m.wikipedia.org/wiki/Aluminium_oxynitride

 

[Art Upton]

https://en.m.wikipedia.org/wiki/Aluminium_oxynitride

Didn't Scotty give away that Formula in the 80s?

 

[tfish]

It would be nice if the nozzle cap/forward closure cap/powder holder was made out of a material that was clear or translucent. That way you can see if the powder is going into that tiny hole. It's a great invention. I'm just trying to make the best better.

Pour a small amount of BP into the BP well...tap the well with a screwdriver...watch the BP disappear down the touch hole. Repeat as necessary..Use wadding to fill well. Use supplied plastic cap or tape to cap off well.

Tony

 

[AeroTech]

Canadian authorization has been received for the AeroTech RMS-75/5120 M2050X rocket motor reload kit. This reload kit contains 5.0 lbs. of propellant and was specifically designed as a High-Power Level 3 motor for international sale without requiring a U.S. State Department export license. A very high delivered specific impulse (Isp) was required to provide M-level (>5,120 N-sec) total impulse using no more than 5.0 lbs. (2,268 g) of solid composite propellant. The certified delivered Isp of the M2050X is 247 seconds.

 

[pugachu]

Canadian authorization has been received for the AeroTech RMS-75/5120 M2050X rocket motor reload kit. This reload kit contains 5.0 lbs. of propellant and was specifically designed as a High-Power Level 3 motor for international sale without requiring a U.S. State Department export license. A very high delivered specific impulse (Isp) was required to provide M-level (>5,120 N-sec) total impulse using no more than 5.0 lbs. (2,268 g) of solid composite propellant. The certified delivered Isp of the M2050X is 247 seconds.

Ahh, so that's why it's a 3 grain motor in a 4 grain case

 

[AeroTech]

Ahh, so that's why it's a 3 grain motor in a 4 grain case

Three longer grains with the core sized to result in 5.0 lbs. propellant.

 

[jd2cylman]

Ahh, so that's why it's a 3 grain motor in a 4 grain case

No no no no, it's Ehh...

 

[n3tjm]

While back I mentioned the advantages and disadvantages of reloads being in the tubes... well today when I opened up a reload for tomorrow launch, one of the disadvantages struck. The reload had two aft o-rings. No fwd end o-ring. I had to open up another load so I can finish loading. Back when the loads were in bags, I could tell when loads had missing parts, damaged parts, wrong parts... Yeah they store nice in tubes, and I guess they protect the liners better, but I personally never though of that as a problem in the 30+ years of using reloads... and putting them in tubes gotta cost a lot more than bags... and since G motors are now upwards of $30...

 

[pugachu]

While back I mentioned the advantages and disadvantages of reloads being in the tubes... well today when I opened up a reload for tomorrow launch, one of the disadvantages struck. The reload had two aft o-rings. No fwd end o-ring. I had to open up another load so I can finish loading. Back when the loads were in bags, I could tell when loads had missing parts, damaged parts, wrong parts... Yeah they store nice in tubes, and I guess they protect the liners better, but I personally never though of that as a problem in the 30+ years of using reloads... and putting them in tubes gotta cost a lot more than bags... and since G motors are now upwards of $30...

I've cracked a few phenolic liners in storage, and had a few loads go bad from swelling and oxidation. The new tubes protect the liners, the new bags slow down the oxidation and swelling. There are disadvantages, but I prefer the tube packaging, personally.