Clustering requiring certification?

[Jacktango22]

Just getting back into this as a retirement gift to myself. I think that I will stay in the mid power range and not seek L1 certification because i can pretty much do all I want to do in the E and F range. BUT what happens if I want to try clustering some F motors together that collectively have the power/impulse seen in L1 certification flights? Maybe there is an easy answer in the literature but I thought I’d try this first. Thanks. love this Forum.

 

[JimByrne]

Total impulse controls the limit

 

[PayLoad]

Total impulse controls the limit

In another words, yes, you would need certification to launch at a sanctioned event

 

[samb]

Welcome back to the party. From the NAR website:
“

1. High Power Certification is required if a person wishes to:​

   1. Launch rockets containing multiple motors with a total installed impulse of 320.01 Newton-seconds or more, or
   2. Launch rockets containing a single motor with a total installed impulse of 160.01 Newton-seconds or more, or
   3. Launch rockets that weigh more than 53 ounces (1500 grams), or
   4. Launch rockets powered by motors not classified as model rocket motors per NFPA 1122, e.g.:
      1. Average thrust in excess of 80.0 Newtons
      2. Contains in excess of 125 grams of propellant
      3. Hybrid rocket motors”

 

[prfesser]

Just getting back into this as a retirement gift to myself. I think that I will stay in the mid power range and not seek L1 certification because i can pretty much do all I want to do in the E and F range. BUT what happens if I want to try clustering some F motors together that collectively have the power/impulse seen in L1 certification flights? Maybe there is an easy answer in the literature but I thought I’d try this first. Thanks. love this Forum.

An F motor has a maximum impulse of 80 N-s, so one could cluster up to four of those motors without requiring certification. Four F motors would be a pretty hefty project.

 

[PayLoad]

Welcome back to the party. From the NAR website:
“

1. High Power Certification is required if a person wishes to:​

   1. Launch rockets containing multiple motors with a total installed impulse of 320.01 Newton-seconds or more, or
   2. Launch rockets containing a single motor with a total installed impulse of 160.01 Newton-seconds or more, or
   3. Launch rockets that weigh more than 53 ounces (1500 grams), or
   4. Launch rockets powered by motors not classified as model rocket motors per NFPA 1122, e.g.:
      1. Average thrust in excess of 80.0 Newtons
      2. Contains in excess of 125 grams of propellant
      3. Hybrid rocket motors”

In another words, yes, you would need certification to launch at a sanctioned event

 

[Jacktango22]

Thank you all. Makes sense.

 

[samb]

I always refer to this handy pictorial reference created by our friend Doug Sams.