[roc-chat] Re: Punisher Drag Race and Discussion of Thrust Misalignment

  • From: Rick Dickinson <rtd@xxxxxxxxxxxx>
  • To: roc-chat@xxxxxxxxxxxxx
  • Date: Thu, 18 Jun 2015 23:12:02 -0700

I can attest to this! Every single time I flew my Estes Fat Boy on a J90, it
vectored off the rail at an angle. Switching from a moonburner to the BATES
J275 cured that.

Offset core = offset thrust.

Cheers,

Rick Dickinson

On June 17, 2015 5:54:56 PM PDT, Cliff Sojourner <cls@xxxxxxxxxxxxx> wrote:

And grain configuration. I am certain that moonburners and C slots
have offset thrust, there's only so much the convergent section of the
nozzle can do.


On June 17, 2015 4:44:03 PM PDT, 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


--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

Other related posts:

  1. Home
  2. roc-chat
  3. Archive
  4. 06-2015