Thursday, August 07, 2014

F15-4 --> F0-0 (a.k.a. you can't light clay) (updated...again)

As I reported yesterday:
I started trying to fly an F15-4 in the Cheetah. After the stock igniter failed to light it, I tried a Q2G2. No go. I decided that maybe there was some clay over the nozzle. I scraped it lightly and tried another Q2G2. Still no joy. More scraping and a home grown igniter. STILL it sat on the pad. I decided to go at the nozzle with a drill bit. After it was way in there and I was still getting clay, I figured out that something was really wrong. I ended up putting it on a static test stand and burning it from the top end. As expected, the nozzle remained plugged. I need to take some measurements, fill out a MESS form, and contact Estes. And, inspect the other motor from the pack! I'll do a separate post as a follow up.
Last night I inspected the motor in question and performed some measurements. Using a caliper, I found the plug, which is clearly visible from the top, is about 3.4 inches down. I measured another spent motor and its nozzle is about 3.9 inches down. This implies the 'bonus plug' is about a half inch deep.

I inspected the other motor from the pack and all my other 29mm E/F motors and found you can see the propellant in the nozzle. That's a good thing. I filled out a MESS form and emailed Estes.





Update

Estes support timeline:
  • I emailed customer support on Sunday.
  • Acknowledgement email received Tuesday.
  • Shipping notice received Friday.
  • Update 2: Two pack of motors received today. Estes made good less than 2 weeks after notification!