The Springfest 2015 on board video was awesome. The pilot chute is a
custom color Fruity Chute we made at some point, I can tell by the colors
and the chute bridle.
-Gene
- Regards
Gene Engelgau
Web: http://fruitychutes.com - Professional Aerospace Recovery Systems
Facebook: www.f <http://www.facebook.com/fruitychutes>
acebook.com/fruitychutes
Twitter: @fruitychutes
Cell: 408-499-9050
On Mon, Jun 15, 2015 at 12:28 PM, <kramer@xxxxxxxxxxxx> wrote:
Couple of things all add up against you here, in no particular order they
are,
1) The relative wind is very much NOT in line with the rocket when it
comes off the pad, the wind was coming from one side, the rocket wants to
turn because of the wind, 2 buttons keep that from happening, once one lts
go for a BRIEF instant the lower one acts like a pivot point.
2) stiff rail, not so stiff mount. Ignoring the rail (assume it as
infinitely stiff) all of the rest of the pad adds to the flex at the top.
This gets magnified by the length of the rail (small angle over long 6')
distance.
3) the thrust isn't in line with the button, small difference but anyone
who has slid a button on has felt what a slight off axis angel feels like.
4) If you leave the rail buttons loose so they spin it creates a
gyroscopic effect off axis creating a torque causing the rocket to twist,
stationary buttons would not have this effect. This is total nonsense but
I cant help throwing another thing for the spinning vs stationary rail
button debaters to obsess about.
Mike Kramer
-------- Original Message --------
Subject: [roc-chat] Re: Rocstock 41 Pictures + Punisher Drag Race Video
From: "Dave Peterson" <woshugui@xxxxxxxxxxxxx>
Date: Mon, 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 <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 <kurtgug@xxxxxxxxx>
*Sent:* ýMondayý, ýJuneý ý15ý, ý2015 ý8ý:ý43ý ýAM
*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-- ROC-Chat mailing list roc-chat@xxxxxxxxxxxxx
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 <Payton@xxxxxxxxxxxxxxx>
*Sent:* ýSundayý, ýJuneý ý14ý, ý2015 ý5ý:ý55ý ýPM
*To:* RocChat <roc-chat@xxxxxxxxxxxxx>
https://www.flickr.com/photos/130292873@N02/sets/72157654165375170
https://www.youtube.com/watch?v=7k1lceVPdbM
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