Should’ve googled that 1st :P
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Troy Prideaux
Sent: Friday, 31 January 2020 9:48 AM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Vibratory compaction
Someone (who operated a couple) told me the primary frequency for RAM
propellant mixers is something like 50Hz? Is that correct?
Troy
From: arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx>
[mailto:arocket-bounce@xxxxxxxxxxxxx] On Behalf Of Anthony Cesaroni
Sent: Friday, 31 January 2020 9:39 AM
To: arocket@xxxxxxxxxxxxx <mailto:arocket@xxxxxxxxxxxxx>
Subject: [AR] Re: Vibratory compaction
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/> http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx>
<arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx> > On Behalf
Of Terry McCreary
Sent: Thursday, January 30, 2020 5:03 PM
To: arocket@xxxxxxxxxxxxx <mailto: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
<mailto: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/> http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx>
<arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx> > On Behalf
Of William Claybaugh
Sent: Thursday, January 30, 2020 11:08 AM
To: arocket@xxxxxxxxxxxxx <mailto: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
<mailto: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/> http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx>
<arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx> > On Behalf
Of William Claybaugh
Sent: Wednesday, January 29, 2020 12:51 PM
To: arocket@xxxxxxxxxxxxx <mailto: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
<mailto: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
<mailto:wclaybaugh2@xxxxxxxxx> > wrote:
Anyone have experience w/ vibratory compaction if solid rocket propellant,
with or without vacuum?
Initial search did not turn up anything specific....
Bill
