Bonding Propellant to the liner

[Aris]

Why does cesaroni say to bond the propellant grains to the liner for c-star, dual thrust and moon-burn motors at least in the 75mm category?

 

[troj]

I suspect it's because these motors are designed to be burned as a monolithic grain, but that presents shipping difficulties. So, they came up with a method of cutting the grains apart, then having the user reassemble them into a monolithic grain.

The one long-burn I have requires not only bonding the grains to the liner, but also to each other, which, to me, implies that they also want to inhibit the ends from burning.

-Kevin

 

[bandman444]

I think other thing to mention is that in high thrust motors the grains can be thrown out the nozzle and possibly clog it. Bonding to the liner prevents that scenario.

The long burn motors require the bonding of the GRAINS to each other and that is to achieve the long burn time. (like the the 54mm AT K185 LB is one long grain.) the M840 can not possibly shipped as a single 3foot long grain so they cut it and have you use the supplied epoxy kit to "glue" them back together.

Hope that helps.

BTW Cesaronis site has all the reload info and instructions. It's neat to read through.

 

[Aris]

I see. Thanks for the help. I also noticed that on the M2250 one grain has a wider core than the other 3.

 

[bobkrech]

Agreed. Bonding the grains to the liner prevent spitting the lower grain casting tubes which may burn out first due to erossive burning, clogging the nozzle and overpressurizing the case.

Bob

 

[New Ocean]

I see. Thanks for the help. I also noticed that on the M2250 one grain has a wider core than the other 3.

Is that intended to be the bottom grain?

 

[Mad Bomber F/X]

Is that intended to be the bottom grain?

Correct.