FastAsleep
Geezer In Training
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- May 22, 2014
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Site: Holtville Havoc
Date: 03/01/19
Rocket: Tube Devil 54 - modified Go Devil 54
Motor: CTI - K260 - 2285Ns 6G54mm Classic Long Burn
Max Altitude: 12723'
Max Velocity: 1246fps (847mph)
Electronics - Missile Works RTX in the nose cone, Missile Works Altimeters RRC3 and RRC2+ in the AV-Bay
Weight on the pad 4394g (9.67#)
The first flight of this was on a CTI I303 to 2846' at 461fps. It underperformed the simulation but I imagine the camera taped to the side was partially responsible. Otherwise the flight went off perfectly with a small drogue at apogee and 48" main at 500' slowing it to 22fps.
While this was built with a supersonic flight in mind eventually, its second flight at Holtville was not intended to bust mach, just tickle it. The Open Rocket simulation had max altitude of 10,605' and max velocity of 685mph. Fortunately, the waiver was 18K. The winds were low and the almost 9 second burn took it straight up. I had eyes on it to apogee and only saw it again when the RTX guided me to it. It landed about 8500' east of the pad site in perfect condition.
Here is the data from the RRC3 altimeter:
And a screen cap from the KML generated by the RTX on Google Earth:
Something about the build:
I used an Aero Pack 54mm motor retainer held in place with one 6-32 screw, screwed to a T-nut epoxied inside the retainer. Having the retainer removable makes it easier to thread smaller motors onto the retainer and to change the harness if necessary. I've used this technique on several 38mm rockets with Giant Leap hard point anchors:
The fins are standard G12 black fiberglass cut at 50 degrees for the leading edge and 25 degrees for the trailing edge. These angles were determined by a painstaking process of "what looks good" and "let's taper the aft end so it doesn’t break if it hits hard" and "what is the easiest to repeat with the chop saw." I'd like to think they made some aerodynamic sense as well but no actual calculations were made to that end.
The weight of the fin set is 429g and the epoxy holding them on is 472g (just over one pound.) There is more epoxy than fin. I was not worried about 54mm G12 tubing failing at mach as much as the fins ripping off, and so far so good.
I have my eye on a K300 or L265 for the GHS launch next fall.
(And I ordered a 3" Go Devil on Wednesday from Madcow Rocketry along with the parts to make a Tube Devil 75.)
Date: 03/01/19
Rocket: Tube Devil 54 - modified Go Devil 54
Motor: CTI - K260 - 2285Ns 6G54mm Classic Long Burn
Max Altitude: 12723'
Max Velocity: 1246fps (847mph)
Electronics - Missile Works RTX in the nose cone, Missile Works Altimeters RRC3 and RRC2+ in the AV-Bay
Weight on the pad 4394g (9.67#)
The first flight of this was on a CTI I303 to 2846' at 461fps. It underperformed the simulation but I imagine the camera taped to the side was partially responsible. Otherwise the flight went off perfectly with a small drogue at apogee and 48" main at 500' slowing it to 22fps.
While this was built with a supersonic flight in mind eventually, its second flight at Holtville was not intended to bust mach, just tickle it. The Open Rocket simulation had max altitude of 10,605' and max velocity of 685mph. Fortunately, the waiver was 18K. The winds were low and the almost 9 second burn took it straight up. I had eyes on it to apogee and only saw it again when the RTX guided me to it. It landed about 8500' east of the pad site in perfect condition.
Here is the data from the RRC3 altimeter:
And a screen cap from the KML generated by the RTX on Google Earth:
Something about the build:
I used an Aero Pack 54mm motor retainer held in place with one 6-32 screw, screwed to a T-nut epoxied inside the retainer. Having the retainer removable makes it easier to thread smaller motors onto the retainer and to change the harness if necessary. I've used this technique on several 38mm rockets with Giant Leap hard point anchors:
The fins are standard G12 black fiberglass cut at 50 degrees for the leading edge and 25 degrees for the trailing edge. These angles were determined by a painstaking process of "what looks good" and "let's taper the aft end so it doesn’t break if it hits hard" and "what is the easiest to repeat with the chop saw." I'd like to think they made some aerodynamic sense as well but no actual calculations were made to that end.
The weight of the fin set is 429g and the epoxy holding them on is 472g (just over one pound.) There is more epoxy than fin. I was not worried about 54mm G12 tubing failing at mach as much as the fins ripping off, and so far so good.
I have my eye on a K300 or L265 for the GHS launch next fall.
(And I ordered a 3" Go Devil on Wednesday from Madcow Rocketry along with the parts to make a Tube Devil 75.)
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