From the simulations, what was the velocity of the rockets when they exited the
rail? Wouldn’t the amount of time this rotation about the aft rail button have
to take place between the top rail button clearing and the bottom one exiting
the top of the rail?
From: Chris Kobel
Sent: Friday, June 19, 2015 7:52 AM
To: roc-chat@xxxxxxxxxxxxx
I recall measuring 11 mph from the WNW at 88 degF at our ~9:50am launch time.
I believe as soon as the top button clears, any rotation would have to take
place about the bottom button.
Chris
From: Kurt Gugisberg <kurtgug@xxxxxxxxx>
To: "roc-chat@xxxxxxxxxxxxx" <roc-chat@xxxxxxxxxxxxx>,
Date: 06/17/2015 05:40 PM
Subject: [roc-chat] Re: Punisher Drag Race and Discussion of Thrust
Misalignment
Sent by: roc-chat-bounce@xxxxxxxxxxxxx
I still am voting for the rail button thing. As soon as the top button clears
it will want to rotate around the cg. Now what is causing the force that
makes it want to rotate? Did we discuss weathercocking on a barely stable
rocket? How hard was the wind blowing at the time?
Kurt
On Wed, Jun 17, 2015 at 4:44 PM, R Dierking <applerocketry@xxxxxxxxxxx> wrote:
So, what do you think? Malformed nozzles, chamber pressure too high, exhaust
gases thrust vector rocket...
Sent from my iPhone
On Jun 17, 2015, at 4:24 PM, "Kurt Gugisberg" <kurtgug@xxxxxxxxx> wrote:
From the video, I could see that my Punisher also veered off after it left the
pad. I had to leave my casing with David because it had a heat bulge in the
end near the forward seal. So it was probably close to catoing too.
Looks like we have a cast of characters that might lead to to behavior we saw:
misaligned thrust vectoring, rail button placement, low level of stability with
high thrust motor. The only thing it might not be is rail whip.
Kurt
On Wed, Jun 17, 2015 at 1:02 PM, R Dierking <applerocketry@xxxxxxxxxxx> wrote:
I’m sure we can come up with things to investigate and even reduce this
misalignment problem.
Who’s interested in a Punisher 2 mass launch? I think we should use the same
K1440 engine and leave it up to each flyer if they are going to modify the rail
buttons, pad, whatever else. We have lots of time to collect details on each
project.
Chris, would it be possible to post some details of the AC stand used to test
for misalignments?
Do you think that creating a way to hold the rocket on the pad until max thrust
is achieved would help?
I’m wondering why David Reese has not joined this discussion because wouldn’t
he be one of the best people to advise on something like this?
Again, I think building a large launch pad/test stand for ROC launches would be
cool and we probably wouldn’t need the contribution of many people to do it.
We could use the pad at Black Rock for XPRS or BALLS. Again, I’m offering to
buy the trailer for the project.
Richard Dierking
