Old grains

[Dipstick]

Hey folks, there are always questions about "can I fly this __ year old motor." I have often flown old motors, but wanted to check with others about this situation.

CTI N1100, has been loaded for over 10 years. Our club recently decided to resurrect the project, and I took apart the motor for inspection. Grains are normal size, slide into and out of the liner normally, and to be honest, I believe it probably would have been fine to fly...

We plan to replace O-rings, and I wondered if any of you folks who build/fly motors of this size often could comment on the grains' appearance. Are they cracked? Do those little divots matter?

 

[eggplant]

Feels like a dumb question, but are you sure that is an N1100? The thrustcurve and burntime suggest it is a moonburner with an off-center core.

 

[Dipstick]

Now that's a really good question. I was told N1100. I do know it's a long burn motor, but can't verify the core geometry. Are all the CTI longburns offset?

 

[Dwatkins]

On Wildman's site it is listed as a 98mm 6 grain moon burner.

 

[Dipstick]

Yup, and according to this CTI document, I have a mystery motor as the grains were not bonded...looks like this is going to end up in the firepit.

 

[crossfire]

Yup, and according to this CTI document, I have a mystery motor as the grains were not bonded...looks like this is going to end up in the firepit.

No reason you can't fly it. Do a little research and fly it. Heck if your going to fire pit it I would take it. As would many others.

 

[rfjustin]

I would guess that to be an N-2500 by CTI.

Replace the o-rings and fly it, grains look good.

 

[Dipstick]

I would guess that to be an N-2500 by CTI.

Replace the o-rings and fly it, grains look good.

Thanks, that makes sense. We have two and I assumed they were both N1100 but that must be the other one.