Does anyone know if the spacers and floating forward closure could be used in a 38mm/720 case in order to use it for some J reloads?
Yes. They can be used in any case of the same diameter.I was just thinking the same thing: Could the spacers be used in a case larger than the 360? A 1080 maybe?
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Each grain in the 38mm line is 120 Newton seconds, right? Are there AT 38/960 loads? 38/840? I was under the impression they jumped from 720 to 1080, in which case the two spacers wouldn't be enough...I was just thinking the same thing: Could the spacers be used in a case larger than the 360? A 1080 maybe?
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Other then not needing the plugged forward closure for the Warp 9 loads, you are right. Here's the link to the Aerotech page with all the motor drawings that show grains etc. http://www.aerotech-rocketry.com/resources.aspx?id=6Each grain in the 38mm line is 120 Newton seconds, right? Are there AT 38/960 loads? 38/840? I was under the impression they jumped from 720 to 1080, in which case the two spacers wouldn't be enough...
So, I think this is the possible loadouts...
1320 -> 1320, 1080
1080 -> 1080
720 -> 720, 600, 480
600 -> 600, 480, 360
480 -> 480, 360, 240
360 -> 360, 240, 120
240 -> 240, 120
120 -> 120
So to cover the entire range, you'd want a 360, 720, and 1320 casing, 2 spacers, aft closure, forward seal disk (comes with the 38/720 casing), standard forward closure (for ejection charges), and sealed forward closure (warp 9's etc), and then you'd be able to use any 38mm reload AT makes I think...
Hmm okay. I thought all the plugged required a plugged forward closure. My mistake.Other then not needing the plugged forward closure for the Warp 9 loads, you are right. Here's the link to the Aerotech page with all the motor drawings that show grains etc. http://www.aerotech-rocketry.com/resources.aspx?id=6
Other then the fact you have a much heavier motor then one with just a 720 case, yes. I don't think the spacers make a whole lot of difference in the larger motors, but they could have some affect with the smaller 29mm.Hmm okay. I thought all the plugged required a plugged forward closure. My mistake.
Incidentally, AT recommends no more than 2 spacers, but they do say there's no technical reason why more can't be used. So in theory, it'd be possible to buy a 1080 case and use three spacers for the 720 loads.
I believe TRA TMT and NAR S&T are not going to allow using more than 2 spacers for safety reasons. Motors with spacers are both longer and heavier than a shorter casing without spacers. These reduces the thrust to weight ratio of the motor and and can reduce the stability of the rocket by adding additional weight at the aft end of the rocket.Hmm okay. I thought all the plugged required a plugged forward closure. My mistake.
Incidentally, AT recommends no more than 2 spacers, but they do say there's no technical reason why more can't be used. So in theory, it'd be possible to buy a 1080 case and use three spacers for the 720 loads.
I don't think the spacers will work in the 1320 case because the grains in that case are longer than all of the other 38mm grains. Looking at the casing itself, it seems like it would hold 10 of the regular 38mm grains.1320 -> 1320, 1080
1080 -> 1080
720 -> 720, 600, 480
600 -> 600, 480, 360
480 -> 480, 360, 240
360 -> 360, 240, 120
240 -> 240, 120
120 -> 120