Hum, if there is significant thrust vectoring the only ‘simple’ solution would
seem to be a designed high rate of spin out of the launcher. Not a big fan of
that.
Dave, if you would like, please join the conversation on the Launch Pads
subject.
From: Dave Peterson
Sent: Monday, June 15, 2015 11:51 AM
To: roc-chat@xxxxxxxxxxxxx
I have had a rocket take a hard turn even out of a tower. (Darkstar Mini at
01:34 on this video https://www.youtube.com/watch?v=ewsgZf2crAQ ). Even a tower
can twist and bend, so maybe they are no better or even worse than a rail from
that perspective. At the time I attributed it to wind, but this was a fairly
high thrust:weight flight so I also wondered about thrust vectoring. When a
motor is static tested on a stand are there also YZ gauges to look for off axis
thrust?
I am planning to use a K1440 as the booster for a two stage with a K250W
sustainer at Black Rock in September so I hope we get to the bottom of what
happened befiore then.
My Open Rocket simulation was predicting 15,100' but I was taking that with a
grain of salt since RockSim 9 was saying closer to 12,000' which "seemed" more
realistic. That said, RockSim has a reputation for over-estimating mach drag,
which on my simlation was about 50% higher than it was in OR.
From: roc-chat-bounce@xxxxxxxxxxxxx [mailto:roc-chat-bounce@xxxxxxxxxxxxx] On
Behalf Of R Dierking
Sent: Monday, June 15, 2015 8:55 AM
To: roc-chat@xxxxxxxxxxxxx
Subject: [roc-chat] Re: [roc-chat] Re: Rocstock 41 Pictures + Punisher Drag
Race Video
The ground and flight videos are excellent, and I don’t want to get far OT but
I noticed the diversions as well Kurt. Interesting that you have basically the
same rockets, engine, and igniter, on the same pads and rails with lots of
differences in the ignition times and way they exited the rail.
Maybe it would be best to start a new thread on launch pads.
Also, hopefully, there will be an analysis about the engine failures because
the K1440WT seems like it would be a great engine for a 2 stage rocket. And,
why did everyone get a much higher altitude than they expected?
From: Kurt Gugisberg
Sent: Monday, June 15, 2015 8:43 AM
To: roc-chat@xxxxxxxxxxxxx
Great Video Dave. It's a little disturbing seeing some of the Punishers came
off the rails at an angle. In the slo-mo you can clearly see a number of them
angling right off the top of the rail. I think that is a common situation with
rails. I think that even thought the rail is so much stiffer than a rod, they
still whip around. Maybe it is slop in the pad but you can see those rails
vibrating back and forth quite a bit in even a moderate wind.
Kurt
On Mon, Jun 15, 2015 at 12:48 AM, Dave Peterson <woshugui@xxxxxxxxxxxxx> wrote:
Here is my video... https://www.youtube.com/watch?v=vFF-6Dwud9U
Thanks to everyone for putting this event togather.
From: roc-chat-bounce@xxxxxxxxxxxxx [mailto:roc-chat-bounce@xxxxxxxxxxxxx] On
Behalf Of R Dierking
Sent: Sunday, June 14, 2015 7:26 PM
To: RocChat
Subject: [roc-chat] Re: [roc-chat] Rocstock 41 Pictures + Punisher Drag Race
Video
Nice!
How many people had on-board cameras?
From: Payton Kramer
Sent: Sunday, June 14, 2015 5:55 PM
To: RocChat
https://www.flickr.com/photos/130292873@N02/sets/72157654165375170
https://www.youtube.com/watch?v=7k1lceVPdbM
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