If we're talking something dirt cheap and sorta hacked together... what
about something like an electric motor out of an old washing machine with
an offset weight?
Joe
On Thu, Jan 30, 2020 at 4:35 PM William Claybaugh <wclaybaugh2@xxxxxxxxx>
wrote:
We used to have to clear the building and warn the neighbors when we did
acoustic testing of spacecraft at a former employer.
Done by a company whose main business was audio for stadium concerts:
just stack the speaker’s high in a small circle and crank up the launch
vehicle profile.
Bill
On Thu, Jan 30, 2020 at 4:15 PM rebel without a job <
rebelwithoutajob@xxxxxxxxxxx> wrote:
Extra vibration can be had with a good sound system. A sufficiently
powerful sound system may obviate the need for the truck.
------------------------------
*Von:* arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> im
Auftrag von William Claybaugh <wclaybaugh2@xxxxxxxxx>
*Gesendet:* Thursday, January 30, 2020 5:07:10 PM
*An:* arocket@xxxxxxxxxxxxx <arocket@xxxxxxxxxxxxx>
*Betreff:* [AR] Re: Vibratory compaction
Ed:
Oh I do wish that would repeatedly work: the last mile of the road out
to the MTA would be perfect....
Bill
On Thu, Jan 30, 2020 at 3:53 PM Edward Wranosky <edwardcw@xxxxxxxxx>
wrote:
Does "vacuum container in the back of a truck on a washboard road" count?
Modulate the frequency with the gas pedal.
On Thu, Jan 30, 2020 at 3:39 PM Anthony Cesaroni <anthony@xxxxxxxxxxx>
wrote:
If you can get your hands on a surplus, high power vibration welder, you
could conceivably build your own for a lot less. The drivers are identical.
They don’t have the advantage of delivering multiple frequencies
simultaneously but they are very effective nonetheless.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
*From:* arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> *On
Behalf Of *Terry McCreary
*Sent:* Thursday, January 30, 2020 5:03 PM
*To:* arocket@xxxxxxxxxxxxx
*Subject:* [AR] Re: Vibratory compaction
Last time I looked at one of those RAM units, I thought it ran to six
figures... Have they come down in price?
Best -- Terry
On 1/30/2020 2:58 PM, William Claybaugh wrote:
Anthony:
Resonate Acoustic Mixing (RAM) appears to offer the ability to mix very
heavily loaded pastes with low shear (in contrast to conventional mixing)
and very quickly (seconds rather than minutes or hours). Since there is no
mixing paddle, there is no vacuum rotary joint and applying vacuum is
trivial.
I’ll apply vibration to the post mixing vacuum for my next test just to
see what improvement that produces but will be looking into using vibration
to get rid of the conventional mixer altogether.
Bill
On Thu, Jan 30, 2020 at 9:31 AM Anthony Cesaroni <anthony@xxxxxxxxxxx>
wrote:
If you mix under a vacuum, vibration should not be required.
One approach I saw being used by an amateur group in the 90s was to mix
the propellant into a simple cylindrical vacuum chamber that had a shaft
connected to a set of blades inside. The shaft had a rotary seal that
permitted the shaft to move in and out the length of the tube as well as
rotate. The tube was made from clear polymer and was about 6” in diameter
and 48” long. I have no idea how well this worked in practice and what was
used to mitigate shaft deflection and possible blade strike. This was the
90s when HPR was the “wild west” of rocketry. They published a brochure
about it that I may still have in my Toronto library.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
*From:* arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> *On
Behalf Of *William Claybaugh
*Sent:* Thursday, January 30, 2020 11:08 AM
*To:* arocket@xxxxxxxxxxxxx
*Subject:* [AR] Re: Vibratory compaction
Anthony:
Yep. But also about understanding the cost of performance.
I’m also wondering about just doing all the mixing with vibration and
vacuum. It seems possible that for 150 lbm. lots that might be a plausible
solution.
Bilk
On Wed, Jan 29, 2020 at 8:19 PM Anthony Cesaroni <anthony@xxxxxxxxxxx>
wrote:
Bill,
Is this about your pursuit of improving propellant density without hving
access to vacuum mixing equipment?
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
*From:* arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> *On
Behalf Of *William Claybaugh
*Sent:* Wednesday, January 29, 2020 12:51 PM
*To:* arocket@xxxxxxxxxxxxx
*Subject:* [AR] Re: Vibratory compaction
Shane:
Is this done after or during mixing?
If the latter, I—and I suspect others—would be very interested in your
process: for example, how long do you apply vacuum / vibration before
casting the grain(s)? Have you documented the difference in final
propellant density?
I found that 10 minutes under vacuum after mixing resulted in density
going from 0.055 to 0.058 lbsm. / cu. in., for a specific propellant
formulation, for example. Do you have a guess as to what additional
density might be achieved from vibration? Note that theoretical is 0.065
for this propellant.
I’m trying to make an economic calculation here: for my next generation
(composite) 6” motors, getting to 0.060 lbsm. / cu. in. Increases
propellant fraction from 70% to 72%; given my estimate of the cost of a
vibratory table, I’m looking to understand if that investment produces
greater performance gain than alternative weight saving investments.
Bill
On Wed, Jan 29, 2020 at 10:34 AM <spcdestiny01@xxxxxxxxx> wrote:
At my school we use the vacuum while it’s on the vibration table to
remove all air bubbles and increase the density.
Hope that helps,
Shane Cullen
Sent from my iPhone
On Jan 29, 2020, at 10:27 AM, William Claybaugh <wclaybaugh2@xxxxxxxxx>wrote:
propellant, with or without vacuum?
Anyone have experience w/ vibratory compaction if solid rocket
Initial search did not turn up anything specific....
Bill
--
Dr. Terry McCreary
Professor Emeritus
Murray State University
Murray KY 42071
