only considered safe to launch from Terry Lee's launch trailer with 20 feet
of very stiff 1515 rail.
+### Revisions for Version 2 ###
+
+Because the main airframe zippered somewhat on the first flight, and the
+ARRD released at apogee, rather than just repairing the existing airframe
+tube, we're going to build a replacement.
+
+To increase stability, the main airframe tube length will be extended from
+the original 4.5 feet to approximately 8 feet. The expected increase
+in stability should allow a reduction in nose weight, increasing
+safety. It should also make recovery system loading less arduous on the
+rail. Of
+course, this means the rocket will be closer to the length of an upscaled
+Nuke Pro Maxx rather than the original Lil Nuke.
+
+For main deployment, the ARRD is being replaced with a
+[Tender Descender L3](https://tinderrocketry.com/l13-tender-descender-tether),
+which has the advantage that the release mechanism is orthogonal to the
+axis of flight. That seems important when the airframe is this heavy and
+apogee occurs at a non-nominal velocity, as in the first flight.
+
+The original build had internal 1x2 ribs and a baffle yielding a "D" shaped
+main bay with the apogee charge gasses going up the channel without pushing
+on the main deployment bag. For this rebuild, 3 ribs will run the airframe
+length between the 12" airframe and a concentric full-length 8" deployment
+bay, with centering rings on each end. One sector of the rings will be
+vented to allow apogee ejection gasses to flow from the charge cups on the
+leading edge of the fin can to push the nose off without push up on the
+main in its deployment bag.
+
## Design / Simulation File
-[mehganuke.ork](/rockets/airframes/MehGaNuke/mehganuke.ork)
+Original [mehganuke.ork](/rockets/airframes/MehGaNuke/mehganuke.ork)
+Revised [mehganuke-v2.ork](/rockets/airframes/MehGaNuke/mehganuke-v2.ork)
## Construction Log
the nose descending under 2 5-foot mil-surplus chutes, and the bulk of the
airframe descending under a 28-foot mil-surplus chute.
-[Tender Descender](http://www.tinderrocketry.com/l13-tender-descender-tether).
-
The stress at deployment tore the strap off the deployment bag, and the
deployment bag was not recovered. After studying the zipper and thinking
about the main deployment sequence, several changes will be made before the
next flight:
- - The main airframe tube will be replaced with a tube that's a bit
- longer (for greater stability), and has an internal 7.5-8" diameter
- tube instead of the flat baffle to ease main chute deployment.
+ - The main airframe tube will be replaced with a tube that's a bit longer
+ (for greater stability), and has an internal 7.5-8" diameter tube instead
+ of the flat baffle to ease main chute deployment.
- - Switch from the ARRD to the largest [Tender Descender](http://www.tinderrocketry.com/l13-tender-descender-tether) for main deployment
+ - Switch from the ARRD to the largest [Tender Descender](http://www.tinderrocketry.com/l13-tender-descender-tether) for main deployment.
- - Add a TeleGPS to the nose assembly so it can be tracked
- independently, and let it come down under the 2 existing 5-foot
- chutes. Add a third 5-foot chute to be a dedicated pilot for the
- 28-foot main chute.
+ - Add a TeleGPS to the nose assembly so it can be tracked independently, and let
+ it come down by itself under the 2 existing 5-foot chutes. Add a third 5-foot
+ chute to be a dedicated pilot for the 28-foot main chute.
These changes should reduce the chance of another zipper, and reduce the amount
of strap we need to stuff into the bay.
projects / web / gag.com / blobdiff