CTI 4G Casing with two 2G Reloads

[niels popping]

does anybody know if you can use view 2g reload kit to fill up your 4G casing
instead of ordering a 4g reload

 

[chadrog]

CTI does make spacers, I think they recommend using no more than two. If you can get the spacers, you're all set!

 

[niels popping]

CTI does make spacers, I think they recommend using no more than two. If you can get the spacers, you're all set!

I know , but what I mean is , If you want to fly with the power of an 4Grain motor,

can you use 2 2Grain reloads in a 4G casing to build your 4G motor

for example you have 2 H reloads, you fit them together to make an I motor.
so you don't need to buy a I reload

 

[chadrog]

Ahh, your first post was a bit unclear. I wouldn't try that.

 

[eggplant]

You would not have a long enough liner, among other problems. Mostly, why would you want to? A 2 grain 38mm motor is about $32, while a 4 grain one is about $45. 2*32 = 64 > 45.

 

[niels popping]

Ahh, your first post was a bit unclear. I wouldn't try that.

I know my English is not that good

because the physical size doesn't support that ?

 

[niels popping]

You would not have a long enough liner, among other problems. Mostly, why would you want to? A 2 grain 38mm motor is about $32, while a 4 grain one is about $45. 2*32 = 64 > 45.

cause I blow up my 2g casing ( CTI)
still have 2 reloads for that
and have a 4 g casing left also from CTI

 

[crossfire]

Is the nozzle going to have the same throat size?? I would not think so.
gp

 

[troj]

If your casing failed due to a motor issue, contact CTI about it.

Regarding 2 x 2g in a 4g casing, there's no guarantee the grain cores are the right size. You also won't have the proper nozzle or liner. All in all, a bad idea to try.

-Kevin

 

[niels popping]

If your casing failed due to a motor issue, contact CTI about it.

Regarding 2 x 2g in a 4g casing, there's no guarantee the grain cores are the right size. You also won't have the proper nozzle or liner. All in all, a bad idea to try.

-Kevin

it was a long time ago,

well than I thing I just have to order a 4g reload to do the job,
safety becomes always on the first place

 

[New Ocean]

Did you blow it up by combining two 1 grain motors by any chance?

 

[bobkrech]

CTI Pro38 motor reloads come as preassembled modules that consist of a delay/ejection charge module, 1 to 7 propellant grains, a one piece motor liner and a nozzle with the proper throat diameter for the reload. If your 2G casing failed with a certified load, contact Pro38.com and they will replace the casing.

If you used your own reload, you're out of luck. CTI casings are not designed for EX, and their reloads are not designed to be taken apart, combined, or reused. Ir you want to make your own motors use Kosdon style casings. They are much simpler, have thicker walls, and use snap ring closures.

Bob

 

[Reinhard]

On Pro38 motors, the liner does not only function as thermal protection, it is also part of the seal (note the O-ring in the forward closure). Trying to use a split liner will result in a blow by, destroying the casing and probably the rocket too.

Different motors often share components, but there are more differences than only the number of grains. So if you want to build a "X" motor you can generally not use only "Y" motors, because either the delay element, the propellant, the grain-, nozzle- or liner geometry or any other design detail of the "Y" motors can be different from what you need to build an "X" motor.

Sometimes, these can be quite subtle nuances, like minor tweaks to the grain geometry (larger cores on motors with many grains, shortened grains to make room for seal discs or grain spacers).
Finding out about this little details without access to the OEMs documentation usually involves a couple of less than ideal flights. This might be acceptable for someone who is willing to sacrifice hardware for the purpose of research but recycling reloads for the purpose of saving money is not advisable.


Reinhard