CTI Pro24

[shreadvector]

Im sure a LOC Starburst can take on two G's and H's

I have one of those (built) in my garage.

 

[bobkrech]

You can definately make a 24 mm in the mid H-impulse class, but you are restricted by the amount of propellant you can physically put into the casing. It is hard to envision that you could reliably get I-impulse from a reasonable length 24 mm casing.

Based on a scaling analysis of the Pro29 and Pro38 propellent grain weight per unit length versus perfromance, we might assume that a Pro24 propellant grain would weight about 4.3 g/cm. If the grain length is the same as the Pro29 grain (1.75"), each grain would weight ~19.1 g and generate 40 N/S total impulse. A Pro24 using Classic propellant might be rated ~280H180, ~240H160 (6G), ~200H140 (5G), ~160G120 (4G), ~120G90, ~80F60 (2G) and ~40E30 (1G).

Bob

 

[ben_ullman]

You can definately make a 24 mm in the mid H-impulse class, but you are restricted by the amount of propellant you can physically put into the casing. It is hard to envision that you could reliably get I-impulse from a reasonable length 24 mm casing.

Based on a scaling analysis of the Pro29 and Pro38 propellent grain weight per unit length versus perfromance, we might assume that a Pro24 propellant grain would weight about 4.3 g/cm. If the grain length is the same as the Pro29 grain (1.75"), each grain would weight ~19.1 g and generate 40 N/S total impulse. A Pro24 using Classic propellant might be rated ~240H160 (6G), ~200H140 (5G), ~160G120 (4G), ~80F60 (2G) and ~40E30 (1G).

Bob

Then add in larger cores/nozzle due to the length and you have an even higher thrust shorter burn.

Ben

 

[MarkII]

I'd love to see a full G in 24mm, especially if it's a long burn motor. The Ellis g-37 was a very cool motor, though it wasn't a full G. It's very doable to have a safe, Mach-busting 24mm rocket with dual-deployment and a radio tracker.

11kft on a long-burning full G is probably possible.

A long-burning G was something that I was interested in when I asked Jeroen about Pro24's in one of the many CTI threads several months ago. (It was either here or on RP - I can't remember where right now.) Mid-power Pro24's would be truly a delight. I realized after I posted yesterday that high power 24mm motors would be quite long and pretty impractical, so I take back what I said about CTI and Pro24's yesterday.

MarkII

 

[JDcluster]

This might shed some light on how long the motors might be:

https://blastzone.com/performancehobbies/store.asp?groupid=56



JD

 

[bobkrech]

Then add in larger cores/nozzle due to the length and you have an even higher thrust shorter burn.

Ben

I looked at the Pro38 and Pro29 motors and scaled it to 24 mm assuming the same grain lengths as the Pro29. This would be comparable to the Kosdon 24 performance.

It appears that the bores in the Pro29 and Pro38 motors are the same diameter because both series of motors develop approximately the same average thrust for a given length. This implies that the Pro24 will have a shorter burn time the Pro29 which in turn is shorter than the Pro38. This makes sense, preventing overpressurization, and allow the use of the same throat diameter.

If I am correct, then all the Pro29 propellant combinations could be used in the Pro24 line. What would be really interesting would be to use a dual thrust configuration using several grains of Classic or similar propellant for an initial high thrust kick and V-Max as an endburner for a long low thrust sustainer.

Bob

 

[ben_ullman]

I looked at the Pro38 and Pro29 motors and scaled it to 24 mm assuming the same grain lengths as the Pro29. This would be comparable to the Kosdon 24 performance.

It appears that the bores in the Pro29 and Pro38 motors are the same diameter because both series of motors develop approximately the same average thrust for a given length. This implies that the Pro24 will have a shorter burn time the Pro29 which in turn is shorter than the Pro38. This makes sense, preventing overpressurization, and allow the use of the same throat diameter.

If I am correct, then all the Pro29 propellant combinations could be used in the Pro24 line. What would be really interesting would be to use a dual thrust configuration using several grains of Classic or similar propellant for an initial high thrust kick and V-Max as an endburner for a long low thrust sustainer.

Bob

ok that makes sense. Wasn't sure how you were converting. But yes, it shouldn't be to hard to make the existing mixes work.

Ben

 

[stickershock23]

You also have to think they might be trying different grain configurations, At 24mm a bates grain burns awfully quick. a C-slot or offset core might be better. it helps keeps the burn times longer.

 

[Pantherjon]

All I know is that I can't wait! Have 1 Pro29, but I guarentee you that will NOT be the only one soon!

So, wonder how many Pro24 cases we can expect? 1G thru 6GXL as per the other lines?

 

[DRAGON64]

CTI has posted the first pic over at RP of the new PRO24 6-grain in action...Blue!!

https://www.rocketryplanet.com/forums/showpost.php?p=154496&postcount=38

 

[The EGE]

Only a G50? I'm hoping that's a full G; I've come around and decided that I want to see a baby H in 24mm

Imagine... flying a Viper IV on J impulse :dark:

 

[ttabbal]

CTI has posted the first pic over at RP of the new PRO24 6-grain in action...Blue!!

https://www.rocketryplanet.com/forums/showpost.php?p=154496&postcount=38

Looking good! I'll be interested in these. Particularly if they do some long burn motors. Or some VMax, I'm fine with glassing a small tube for 24mm HPR! :roll:

Some 24mm long burn F and G motors would rock. I'd also love to see some more action like the AT combo motors. 1 fast grain followed by some endburn grains. I really need to order a closure and a few of those reloads.

 

[ScrapDaddy]

Only a G50? I'm hoping that's a full G; I've come around and decided that I want to see a baby H in 24mm

Imagine... flying a Viper IV on J impulse :dark:

This is getting intresting......:eyepop:

 

[Initiator001]

Only a G50? I'm hoping that's a full G; I've come around and decided that I want to see a baby H in 24mm

Imagine... flying a Viper IV on J impulse :dark:

I flew a Viper III on G55s.

 

[green dragon]

I flew a Viper III on G55s.

F101's at NARAM 37.

that was fun, and fast

these look to become fun additions to the hoard.

 

[JDcluster]

I still have some:dark:



JD

I flew a Viper III on G55s.

 

[cjl]

I still have some:dark:



JD

I still have some F101s (4 of them, to be precise). I'm still trying to figure out what I want to fly them in...