Troy:
All aluminum structure, 1st stage has a 0.250”’wall; the fins are attached
via countersunk 3/8-16 fastners from the inside of the motor tube; I’ll
post some images later.
Bill
On Mon, Apr 2, 2018 at 9:44 PM Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx>
wrote:
Bill,
Yes, please share images.
What is the casing materials?
You say you’ll be screwing the fins on to the 1st stage (photos will
probably answer this question) how are you structurally attaching the fins
to the casing – I’m assuming it’s all monocoque style structure (engine
casing is airframe), so like, what are they screwed into?
Thanks,
Troy
*From:* arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
*On Behalf Of *William Claybaugh
*Sent:* Tuesday, 3 April 2018 1:10 PM
*To:* arocket@xxxxxxxxxxxxx
*Subject:* [AR] Re: RRS 75th Anniversary Symposium
Troy:
Not much too it. It’s mostly 1990’s amateur technology level and
derivative of the ‘96 dart booster. USC is doing far more impressive work
these days.
Details:
1st stage is 9” diameter, about 90” long including a 9” to 6” transition.
Just over 69” long propellant grain (about five 14” Bates grains if that
were the plan). Compared to the standard RRS composite propellant (the
Anderson / Garboden formulation for field casting) there is about 10% more
propellant mass to be found by vacuum casting and another about 3% from
going to a center burning case bonded grain instead of Bates
cartridges;that would push overall performance toward 200 km according to
the sims.
The 2ed stage is 6” diameter and 60” long and again will benefit from a
center burning and vacuum cast grain.
Payload is a 6” long cylinder topped by a 5.5:1 Von Karman; Titanium tip
on the nose.
The sims say Mach 5.2 @ 75k feet (the second stage coasts for about 20
seconds before igniting at around 45k feet); the upper stage will require
ballast to keep to a maximum of Mach 5.2 as it probably becomes
aerodynamically unstable at about Mach 5.5...according to the sims. Thus
packing more propellant may have a practical limit w/o bigger 2ed stage
fins.
I’m screwing two fins onto the first stage tomorrow and can post an image
from my workshop after that if you or others are interested.
Bill
On Mon, Apr 2, 2018 at 7:55 PM Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx>
wrote:
Bill,
Can you enlighten us a bit on your project? Sounds exciting.
Regards,
Troy
*From:* arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
*On Behalf Of *William Claybaugh
*Sent:* Tuesday, 3 April 2018 3:53 AM
*To:* arocket@xxxxxxxxxxxxx
*Subject:* [AR] RRS 75th Anniversary Symposium
The RRS will be hosting a Symposium at the Gardena, CA Community Center on
Saturday, 21 April to celebrate the 75th Anniversary of the Society.
I will be showing my two-stage, 150km capable hardware at the Symposium.
Detains are in the attached brochure.
Bill