Grain core diameter for a CTI L265 Pro54-6GXL motor

[plugger]

Does anyone out there know the diameter of the core in a CTI L265 mellow motor? Basically I'm looking for the value of d in the image below.

I've got one of these motors on order to use in a sustainer and I'd like to start getting everything together to make some staging pellets to both test and use in my flight but I'm not sure what the core diameter of the grain is.

Any advice is appreciated folks.

 

[mikec]

Doesn't this motor already have a BP pellet in it?

 

[plugger]

Yes but I'm replacing the stock CTI forward closure with a CCR HEI forward closure to use it in a sustainer. If a BP pellet will provide reliable ignition at over 15k' and at near mach speeds I might consider using it but to be honest I think I'd be better off with a BKNO3 augmented ignitor all things considered. Hence the question regarding grain core diameter.

 

[manixFan]

I’ve flown several and in my experience they ignite very quickly so I don’t think you’d need to augment it. The nice thing about the BP pellet it that is it held firmly in place. As long as the ignitor is very near it I think you would get good ignition. At Balls I got 20,500’ in a MD 54mm rocket. I think it would be a great sustainer motor.


Tony

 

[plugger]

I’ve flown several and in my experience they ignite very quickly so I don’t think you’d need to augment it. The nice thing about the BP pellet it that is it held firmly in place. As long as the ignitor is very near it I think you would get good ignition. At Balls I got 20,500’ in a MD 54mm rocket. I think it would be a great sustainer motor.


Tony

Thanks for the reply Tony. Is the BP pellet easy to remove from the stock CTI forward closure? I've never attempted it so it's a bit of an unknown for me.

 

[ECayemberg]

Thanks for the reply Tony. Is the BP pellet easy to remove from the stock CTI forward closure? I've never attempted it so it's a bit of an unknown for me.

I'm fairly certain that the pellet is in the top grain, not the forward closure. Agreed with the rest that say that the stock pellet is sufficient for quick, reliable ignition. Flew one a few years back; great motor!

 

[GRIFFIN]

Eric is correct, the pellet located on the upper grain. The foreclosure only houses the smoke grain

 

[manixFan]

Here's a photo of the one I flew at BALLS. (Obviously pre-flight!) I was told to run a small bead of epoxy around the forward closure shoulder (I just ran it around the top inside of the liner) and to rotate the closure when I mated it to the liner and fuel grains. This supposedly helps seal the liner/forward closure area to help prevent blow-by. It looks like it would easy enough to remove the pellet.

Let us know how it works out,


Tony

 

[manixFan]

Here's an animated gif of my last L265 launch. You can see it goes from off to on in one frame and then left in a hurry. One of my favorite motors.


Tony

click for full-size: