jimzcatz
Boss, Carolina Rocket Mafia
Thanks for the update Tim.
Do the grains move inside the assembled motorI disassembled the motor and grabbed a few pictures. The first shows how far into the liner the nozzle will seat, when the forward seal disk is installed. The other two show the length of the liner.
It does look like the liner is somewhere around .1" or .15" shorter than specified on the assembly drawing. Worst case, I'll take the liner from another reload for the flight next weekend.
How about cutting a little off 1 grain?I disassembled the motor and grabbed a few pictures. The first shows how far into the liner the nozzle will seat, when the forward seal disk is installed. The other two show the length of the liner.
It does look like the liner is somewhere around .1" or .15" shorter than specified on the assembly drawing. Worst case, I'll take the liner from another reload for the flight next weekend.
I'd like to follow up on my own question with another.Any timetable update on the 24mm Q-jets?
I tried to assemble a 54mm motor at Red Glare 2021. It was a J415R. The rear nozzle would not fit into the liner at all. I tried to shave down the inner edge of the liner. When I seated the nozzle I used too much force and the o-ring was compressed until it bulged. Then I couldn’t get the grains, liner, nozzle, and o-ring into the case. I probably should have taken the whole thing home and done the repairs on my workbench rather than in the field. $85 wasted.
Your saying on some reloads a seal disk goes on nozzle end and forward closure end?It’s working for me. I’m not gonna wrestle with it when I have a lot of extra forward seal disc o-rings. Everything still fits fine.
No. I use the forward seal disc at the forward end.Your saying on some reloads a seal disk goes on nozzle end and forward closure end?
That's what I thought.No. I use the forward seal disc at the forward end.
We were at Red Glare 2021. You can always ask us or any dealer to help you.I tried to assemble a 54mm motor at Red Glare 2021. It was a J415R. The rear nozzle would not fit into the liner at all. I tried to shave down the inner edge of the liner. When I seated the nozzle I used too much force and the o-ring was compressed until it bulged. Then I couldn’t get the grains, liner, nozzle, and o-ring into the case. I probably should have taken the whole thing home and done the repairs on my workbench rather than in the field. $85 wasted.
Late April to Mid-May estimate.Any timetable update on the 24mm Q-jets?
Strange. Please contact Karl at [email protected]I disassembled the motor and grabbed a few pictures. The first shows how far into the liner the nozzle will seat, when the forward seal disk is installed. The other two show the length of the liner.
It does look like the liner is somewhere around .1" or .15" shorter than specified on the assembly drawing. Worst case, I'll take the liner from another reload for the flight next weekend.
Thank you. Since I want to fly this weekend, could I use the liner from a K2050 reload in place of the K550 liner?Strange. Please contact Karl at [email protected]
On the RMS 29/40-120, the delay o-ring gets compressed during tightening of the closures:(Note: cross-posted)
Hi, apologies if this is a silly question since I've only just returned to the hobby after years away...
When assembling my 29mm reloads (one 40-120 and the other 180-240 both are new old stock), I noticed that the delay or delay spacer sits proud out of the forward closure (based on the 40-120 instructions it's supposed to)...this means there is a space between the fwd closure and the forward insulator/seal disk and the forward o-ring can be loose...unless the center of the seal disk flexes in towards the grain?
View attachment 459550
View attachment 459551
Of note is that in the past I probably have assembled dozens of reloads, never had any failures and just now noticing/realizing this.
Edit: Is the o-ring held in place by the pressure of the motor burning and more to prevent gas from escaping the sides of the fwd closure?
Yes.Thank you. Since I want to fly this weekend, could I use the liner from a K2050 reload in place of the K550 liner?
On the RMS 29/40-120, the delay o-ring gets compressed during tightening of the closures:
http://www.aerotech-rocketry.com/cu...s_assy_dwgs/29mm_mr_rms/29-40_f22-7j_assy.pdf
On the RMS 29 high power style casings, this is not the case:
http://www.aerotech-rocketry.com/cu...gs/29mm_hp_rms/29-180/29-180_h128w-m_assy.pdf
Reinhard
On the high power hardware, the spacer should not protrude beyond the delay insulator by more than about 1/32”.Thanks Reinhard! That was the key point...I didn't think the delay o-ring would compress 1/16", but just tested it and it does for the RMS 29/40-120. However if that is not the case for the RMS 29 high power, I am surprised the spacer sits even higher (about 1/8"). However cranking down on the assembly seems to crush it a bit and also compress the delay o-ring, so for mine it behaves same as the 29/40-120.
I appreciate the response and information since uncertainty on a reload is never a good thing!
Are you going to bring some to NSL, perhaps?Late April to Mid-May estimate.
So is this a problem?On the high power hardware, the spacer should not protrude beyond the delay insulator by more than about 1/32”.
What am I looking at?So is this a problem?
the spacer protruding beyond the delay insulator by more than about 1/32” on my 29/180-240 reload forward assembly (including adapter).What am I looking at?
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