Saturday, November 28, 2020

Whoops!

I only made 2 flights at the November HARA launch; the first was that of the RX-16, described in the last post, and the second was the maiden flight of my Quest Q E-Z Payloader, a "Qwik Kit" I acquired many moons ago. It was recommended by Art Upton as a good starting rocket to loft his BoosterVision Mini GearCam, a 2.4 GHz camera that live-streamed the video to a receiver, much like the way it is done by NASA, Space X and ULA. While I tested the GearCam on the ground, I never got around to flying it - and for the life of me, I can't remember why. Anyway, the Q E-Z Payloader has sat on the shelf for over a decade, until I decided to launch it two weekends ago.

Quest Q E-Z Payloader (Click to enlarge).

And the rocket did carry a camera, even though it was not the one for which it was purchased. I taped the Estes camera to the side of the payload section, and, just to make things more nerdy, loaded a Perfectflite PNUT into the compartment. A quick weight check indicated that an Estes C6-5 would be about perfect for the flight - I estimated a peak altitude of around 350 feet, which was high enough to get good footage, but not so high as to make for a long walk. Yep, I had thought things through and prepared pretty well.

Uh huh...

The Q E-Z Payloader left the pad and headed up into the blue sky. I watched it arc over and was pleased to see the nylon Apogee chute deploy. But then I caught a glimpse of other pieces falling, and that's when it hit me...

I had forgotten to tape the nose cone to the payload tube, so it would stay in place throughout the flight.

So those two additional falling pieces were the nose cone (no big deal) and the PNUT altimeter (big deal, to the tune of $60). And I did not see where they landed, so I did not have a location to search.

Sighing, I trudged after the rocket, having little hope of recovering the nose cone or, more importantly, the altimeter (assuming it survived the fall). But fortune did smile upon me, for as I was returning to the flight line one of the rocketeers at the high power pads handed me the altimeter. He had heard it beeping - PNUTs are noisy little beasties - and located it on the ground using the sound. I also got back the nose cone, which was a minor miracle. The model has been put back on the shelf, ready for its next flight. And I hope to not be as stupid for that one.

Anyway, I downloaded the data from the altimeter - which appears to be undamaged, as it fell in its holder tube - and got an answer to the question "What does an altimeter record as it is free falling to the ground?" Apparently the tumbling results in oscillations, as you can see from the below graph. The altimeter was also not as snug in the holder tube as I would have liked, and that also shows in the flight profile. At least my motor choice was correct.

Q E-Z Payloader flight profile from November HARA launch (Click to enlarge).

Being taped to the side of the payload section, the camera stayed with the rocket, and I managed to pull a few interesting frames from the video:

Ignition (Click to enlarge)!

Coasting upward (Click to enlarge).

Parachute deploy (Click to enlarge).

Altimeter and nose cone falling away (Click to enlarge).

So a good ending came out of a royal screw-up on my part. That does not happen often.

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