Thursday, July 15, 2010

Hat of Death status report (update)

Scratch - Sweat-Stained Clifton Tracking Station Hat of Death:  53 flight(s)/26 configurations(s)
Your Flights - 2x Est SU D12-0, 4x Est SU D12-P, 9x Est SU A8-3, AT EconoJet F20-P, AT EconoJet F21-P, AT EconoJet F23-P, AT EconoJet F42-P, AT EconoJet G35-P, AT EconoJet G38-P, AT RMS E18-P, AT RMS F12-P, AT RMS F24-P, AT RMS G64-P, AT RMS G69-P, AT RMS G76-P, AT SU G75-4, AT SU G77-P, AT SU G80-P, DRD F38-P, DRD Vulcan G, Ellis SU F20-4, Ellis SU F20-P, Ellis SU G20-0, Ellis SU G35-P, Est SU D12-0/Est SU E9-P, Est SU E9-P

This is the summary motor usage info as kept in EMRR. These flights include 24mm, 29mm, 38mm and 2 cluster configurations. I didn't scour the logs (EMRR's database is sick) but I only remember 5 bad flights:
  1. One cluster flight was unstable due to a msifire;
  2. One of several D12/E9 CHAD staged flight was underpowered, possibly due to a draggy rod (?);
  3. It was unstable on an Ellis G20;
  4. The unknown Vulcan motor (listed as DRD Vulcan G to get it in the database) chuffed and it was off the rod before the motor was up to pressure;
  5. And, lastly, it was unstable on the AT G75.  You can find a photo showing the resulting 360-degree spark field here.
The G20 and G75 flights were surprising since it's flown well on E9's on the low end and an RMS G64 and SU G80 on the high end.  I suspected the motor length may be to blame but the G75 is almost exactly the same length as the G64's case.  Both are longer than the G20, which is longer than the old style G80.  ?????

Update:   After the original post, I added some wraps of duct tape around the Hat of Death's core to help stabilize it in the hat itself.  I flew it twice at ESL-146 with mixed results. The first flight utilized a D12-0 CHAD staged to an E9.  This was  underpowered to the max and was the 6th failed flight out of now 55 total.  The E9 lit after impact resulting in a pucker factor of 8.5.  Given the weird anemic boost of my Under Dawg flight (also a D12-0), I wonder if my batch of D12-0's is funky.  Here's what this motor combo is supposed to do! Hardly the same.  The other difference is the video shows the Hat flying of a 3/16" rod whereas the latest failure was off a 1/4" rod.  Maybe the 1/4" rod was a little cruddy and added some drag that the D12 couldn't overcome effectively? Well, just to test the Rocket Gods, I loaded up another G75...and the Hat was redeemed!  I'm thinking there are 2 failure modes (not counting major motor chuffs or cluster misfires): 1) the D12 CHAD flights are on the hairy edge of being under powered, and 2) the Hat's core had loosened somehow making it more sensitive to the longer, higher thrust motors.