Need Help with Delay Time for PML Tethys

[Rob Campbell]

I'm in a bind. I've been busy at work and am planning on my L2 cert flight at work. I haven't installed a sim program yet so I might not be able to run a sim myself.

My questions is what delay time should I use with a PML Tethys flying on an AT J275?

Thanks in advance for the assistance.

Rob

 

[Handeman]

A quick check on https://www.thrustcurve.org/motors/guide/647a02a5acf1910002229f94/summary.html says 11.2 seconds. That is using the PML estimated 62 oz. weight for the rocket. You can adjust that to your actual weight.

 

[Rob Campbell]

A quick check on https://www.thrustcurve.org/motors/guide/647a02a5acf1910002229f94/summary.html says 11.2 seconds. That is using the PML estimated 62 oz. weight for the rocket. You can adjust that to your actual weight.

Thank you! I will go with 10 or 12 seconds, depending on weight.

 

[Rob Campbell]

I just checked Apogee's website and used their Katana as a similar rocket (a little heavier) and Apogee recommends a 12 second delay on a J275. So, unless my Tethys is grossly overweight, I will go with 12 seconds.

 

[tsmith1315]

A L2 cert flight with motor ejection, simple and clean. I love that confidence, Rob!

 

[Handeman]

I just checked Apogee's website and used their Katana as a similar rocket (a little heavier) and Apogee recommends a 12 second delay on a J275. So, unless my Tethys is grossly overweight, I will go with 12 seconds.

Not sure where you are located, but at our field in VA if the winds are up over 10 mph, 4000 ft. with motor eject is a little dicey without a tracker or JLCR. I'm sure you've considered that already.

Good Luck

 

[Rob Campbell]

Not sure where you are located, but at our field in VA if the winds are up over 10 mph, 4000 ft. with motor eject is a little dicey without a tracker or JLCR. I'm sure you've considered that already.

Good Luck

I'm flying with the SEARS club in Samson, AL. The field is a sod farm. I have a JLCR, which I might use just to avoid going on a Lewis&Clark-esque expedition to get it back.

 

[Handeman]

I'm flying with the SEARS club in Samson, AL. The field is a sod farm. I have a JLCR, which I might use just to avoid going on a Lewis&Clark-esque expedition to get it back.

I found the SEARS NAR 572 website and a Tripoli #38 website on an insanerocketry.com hosted site, but I couldn't find any up todate information with launch schedules, whether they are NAR or Tripoli launches, or anything about COAs or altitude limits. We'll be taking a trip from Georgia to Louisiana with our camper in the next year or so. I would love to spend a couple days launching there along the way. How do I find out their schedule and info on their launches?

 

[tsmith1315]

How do I find out their schedule and info on their launches?

https://sears572.org/

Also check the launch schedule on Chris' site, when he's there:

https://www.csrocketry.com/launch-schedule-2022.html