Ground Testing - Blocking MMT

[jcampb81]

What are some methods you guys use to block the MMT when doing ground testing for deployment charges?

In previous builds, I’ve used old SU 38mm motors that I’ve epoxied the charge well closed to simulate what it would be like in flight. My newest project has a 75mm mmt that I’m adapting down to 54 but I don’t have any old SU motors that I could use. Would duct taping over the forward end of the mmt be fine?

 

[Crazyrocket]

I just use a reloadable motor case with closures on it. If some pressure leaks out in this condition and the ejection is still good, then it will be fine during the actual flight. If you are really concerned about the leakage, then you could put tape over the forward closure. I've done it both ways.

 

[Banzai88]

I put an empty case in the mount with the ejection hole taped closed. Works fine.

Yes, taping over the fwd end of the motor mount would work, but I would stuff a rag or something else up there, too, for some reinforcement.

 

[DerRedMax]

Why not stuff a nomex blanket down the booster tube to block the hole for the test?

 

[Worsaer]

I agree that an empty casing works great.

Just in the ”For what it’s worth” category, a Rainbird sprinkler cap fits the 54mm Aeropack retainer perfectly…

 

[jcampb81]

Thanks for the replies. Worth noting that I only have Loki cases. I can’t thread the forward retainer like you could with an AT. Tape sounds like the best option.