They will fire, but you will lose some thrust from slightly slower burning. Hopefully Mr Aerotech can give us an idea % reduction in performance at say 0C, -20C, -40C. (-40 is the point °C & °F are equal)
The bigger issue us making sure your recovery system works.
*Nosecone fit changes a lot as the cardboard tubes vs plastic nosecone expand and contract at different rates.
* parachute material doesn't flex as well.
* Landing on a frozen lake is like landing on concrete, keep decent velocities down.
One final note, any breeze that can catch the chute/streamer will drag the rocket across the ice till it gets to the far shore... don't ask how I know...
That's really interesting. I've been thinking about testing motors at various temperatures to see how much the thrust curve could be optimized for altitude in a given airframe.
Just had an issue today. F42-4T with a VERY SHORT delay. Motor lit and took right off, no chuff, slow light, etc. But from ignition to ejection charge was 3.2 seconds. (Per video analysis.) Needless to say chute deployment at high speed.
Burn time 1.3sec
Coast time 1.9sec
Photo shows motor code. Anyone else see this on this batch? ( 052120 )View attachment 437639
Since we are on the topic of motor and environmental temperatures (in this case, launch temperature). I would like to know the tolerable temperature range for storing motor reloads and DMS motors.
That's one seriously spendy paperweightFolks... If you bought the Wildman tailcone closure, and was wondering why the disclaimer was on his website to not use these tailcone closures with Medusa nozzles... Here you go. This was a 75mm 2 grain white lightning load. K540 or something?? Would make a very cool paperweight!
View attachment 437775
I think this post answers your question:When will AT replace the medussa nozzle with single throats? Or when will AT advise which single throat and bore we can use from the RCS store on loads with the medussa nozzle?
Thanks. I saw that prior but was also inquiring about the 54mm motors. I see that is for the 75mm motors. All the 38mm motors are single throat as well, right? I've got a lot of tailcones.I think this post answers your question:
Thanks. I saw that prior but was also inquiring about the 54mm motors. I see that is for the 75mm motors. All the 38mm motors are single throat as well, right? I've got a lot of tailcones.
Would you be willing to share some of your combos in PM? Are you using the RCS propellant? I keep gaining and losing interest in EX going the RMS and DMS route.I use Aerotech nozzles when I make reloads for Aerotech hardware. I calculate the single throat nozzle size (for the Kn I need). If I'm using a Medusa nozzle, then I will determine the throats. (1/2 the area in center for using 4 throats, 1/3 in center if using all 7 throats. If the single throat comes out less then about 7/16", I'll use a small hole closure and a 29 mm nozzle.
Karl got back to me quickly, stating the same as post https://www.rocketryforum.com/threads/aerotech-open-thread.125657/post-2055931. The delays supplied with the motor will be +/- 1s. I appreciate the answer!
Regarding HDKs, he stated they're in compliance with a large percentage of the motors, so are not altered. So it seems YMMV more with HDKs than those supplied with the motor. I used these back before I was comfortable drilling delays, now I just get the longer delay packs and drill them with the 18-38 RMS DDT, or a drill bit with stop adjusted using a 1/32" graduated ruler.