View Single Post
  #19  
Old 02-26-2018, 11:28 AM
astronwolf's Avatar
astronwolf astronwolf is offline
Lost his Drifter
 
Join Date: Mar 2013
Location: Northeast Ohio
Posts: 1,277
Default

I have a pack of B4-6 motors that I won as a door prize at NARCON.

These are standard sized 18x70mm motors.

The cases are not cardboard, so they aren't going to swell.

They are composite motors, so they aren't "pressed" like blackpowder motors. They are not going to be bulged from compressing the propellant.

The aft end appears to have a modular delay train/ejection charge thingee glued in.

The nozzles appear to be some sort of clay. I was told the nozzle throat is 0.09-inches in the B4 motors. I did compare a fired case with a new case to check how much nozzle erosion occurred, but I did not have a way to measure it. Erosion looked like "a little bit." This is a much wider throat than the notorious old Apogee B7 motors. I asked Gary how he was able to increase the size of the nozzle throat, and he told me that it is a combination of using a hot, new composite propellant and grain geometry. He said that developing and testing these motors was a very time consuming and difficult project.

Can't wait to fly them.
-W
__________________
-Wolfram v. Kiparski
NAR 28643 - TRA 15520
MTMA Section #606 President
Reply With Quote