[NRVR-Members] Anyone Ever Use RCS Motors?

Mon Jun 4 09:50:11 CDT 2018

You can actually get the feel of all this trough RCS without a huge outlay.  For example, they have a 54 mm grain that is 18.5 " long for $59.99.  This will be as if you poured your own 18.5" composite fuel tube and now you will put a motor together, which will include cutting the 18.5" tube  into smaller pieces and drilling out to produce a core burner.   They also note on the 54mm page which hardware this works with, one of which of course is Aerotech.

If you do not like the steps after buying the grain tube, no need to proceed with learning to  pour your own.
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On Mon, 6/4/18, Adrien Drouault <adrien.drouault at gmail.com> wrote:

 Subject: Re: [NRVR-Members] Anyone Ever Use RCS Motors?
 To: "NRV Rocketry Members" <nrvr-members at server2.nrvr.org>
 Date: Monday, June 4, 2018, 10:40 AM

 Noting, of
 course, that I'm still not appropriately certified, and
 won't mess with anything until I am ... (Level 1 at June
 or July launch; Level 2 by October, hopefully).
 I'm still very interested,
 including (maybe "especially") the machining side
 of it (though still trying to find room in the budget, and
 garage, for a lathe :-) ).

 On Sun, Jun 3, 2018 at
 12:46 AM, Thomas Tweeks Weeks <tom at theweeks.org>
 wrote:
 Thanks
 for the great reply Chris..

 I know you've gone all hard core, home-brew lathing
 etc.. I don't think we're there.. Especially since
 the majority of our launches here (with our 10k waiver that
 we rarely break 8k on) and while we have flown some 98mm
 here.. we mainly fly on 75mm and lower (a lot of 54.. and a
 ton of 38mm).

 Yeah.. a couple NRVR have members have mixed before.. and
 we're to that point that a few of us are starting to
 sniff at doing it.  You make a great point about all
 choosing to go with the approximate same research motor
 hardware so we can settle on standard/same liners, grain
 dimensions, molds, share parts, etc.  The VT student group
 just got a static test rig too, and we're getting a nice
 (long distance) wireless LC system.. so we're in a good
 place to start playing around with mixing and doing motor
 tests.

 Tell me.. do you have a dedicated test casing with tapped
 pressure transducers?  Kind of.. one for testing and one
 for flying? (just curious)

 Sounds like we should discuss some of these points you bring
 up.. just to get the most out of it "as a
 club".

 If anyone else has any thoughts.. please chime in.  I'm
 not so much leading the discussion as much as I am just
 poking people to get a sense of people's thoughts who
 are interested in it.

 Tweeks

 On Saturday, June 2, 2018 6:15pm, "Maier.chris"
 <maier.chris at gmail.com>
 said:

 > ______________________________ _________________

 > NRVR-Members mailing list

 > NRVR-Members at mail.nrvr.org

 > http://server2.nrvr.org/
 mailman/listinfo/nrvr- membersTWeeks,

 > 

 > I think the Aerotech hardware & reloads have all
 been tested and are NAR approved

 > true commercial reloads.  The RCS components at one
 point may or may not have been

 > as completely tested as the Aerotech stuff and was
 therefore

 > “experimental”.  Not sure if that’s still true
 these days.

 > 

 > Most experimental motors work just fine in the Aerotech
 or RCS hardware that is

 > 75/76 mm and smaller - as long as you get a casting set
 & liner that fit the

 > hardware properly....  At 98mm and above, I buy
 quality aluminum tube and have it

 > machined myself.  I have a lathe that I can build
 closures and graphite nozzles

 > on.  This typically leaves me with a tube that isn’t
 anodized, which is

 > actually sub optimal - I need to set up an anodizing
 rig.  Building your own tubes

 > isn’t “better”, I do it simply because it can be
 more cost

 > effective since I’m not getting “DOM” material
 (drawn over

 > mandrel). DOM is horridly expensive and there are
 minimum quantities that no

 > single user would be able to afford or use if it’s
 not a stocked dimension. 

 > If a supplier has some left over DOM material, or
 it’s a dimension they

 > stock, it’s 1.5x or more the price of plain tube. 
 But plain tube

 > isn’t as round and wall thickness varies
 significantly more than DOM.  I was

 > REALLY bummed out when tru-core quit making cases. 
 Loki is a great alternative,

 > just slightly more expensive.

 > 

 > Rocket motors, much like the camera “Cannon vs
 Nikon” debate (non

 > professional photography) really boils down to - what
 do your friends and family

 > have so you can borrow things.  Rocket motor hardware,
 IMHO, works similarly - buy

 > what the majority of your friends have so you can
 borrow, trade, and sell parts

 > and reloads with each other.  Or if you are doing Ex
 motor casting with your

 > friends, you don’t have to worry about confusing
 liners and casting tubes

 > that are incompatible with one another (Loki vs gorilla
 vs Aerotech etc).  We have

 > mixing parties here, and four or five guys will show
 up.  So not having to run

 > specific batches and not have to pay super close
 attention to the liners etc is

 > beneficial to us.

 > 

 > Last but not least, if you are doing Ex motor mixing,
 just like your ejection

 > charges, you should be testing your motors - at least a
 representative diameter in

 > order to validate your pressure assumptions, burn
 rates, and all that Jazz.  Only

 > then will you know if you actually have a “super
 aggressive” motor and

 > then you can make alternative hardware selections if
 necessary.

 > 

 > Chris

 > 

 >> On Jun 2, 2018, at 16:28, Thomas Tweeks Weeks
 <tom at theweeks.org>
 wrote:

 >>

 >> Yeah Bob.. that's what's confusing. I
 assumed if RCS was there for the research

 >> motor community, that their casings would
 necessarily have the thicker/heavier

 >> casing walls to handle some of the challenges of
 research loads... no? All I see

 >> is fiberlgass casings, so I'm not guessing you
 get to reuse all the parts (just

 >> the closures and the nozzles a few rimes?).

 >>

 >> Is Loki and others recommended over RCS hardware
 for fully reusable "aggressive"

 >> research/DIY hardware?

 >>

 >> They seem to be really well equipped.. and sell
 everything that's needed...

 >>

 >> Tweeks

 >>

 >> On Saturday, June 2, 2018 7:33am, "Bob
 Schoner" <bob.schoner at gmail.com>
 said:

 >>

 >> Yes Gary Rosenfield started and is the owner or
 Aerotech. He also started

 >> Rosenfield consulting services (RCS) maybe 10 years
 ago to service the research

 >> community.

 >>

 >> If you’ve flown Aerotech motors, you have used
 RCS stuff. I think the

 >> disclaimer is meant to say that the commercial
 hardware does not have the wall

 >> thickness needed if you are making very aggressive
 propellants. It seems to hold

 >> up just fine with aggressive AT reloads, but
 generally people doing research use

 >> thicker walled cases like Loki, AMW, and Mostly
 Missiles. In my experience this

 >> is what I’ve seen.

 >>

 >> Bob

 >>> On Sat, Jun 2, 2018 at 7:15 AM David Bloom
 <dwskb at att.net>
 wrote:

 >>> Yes.  Our emails crossed.

 >>> ------------------------------
 --------------

 >>> On Sat, 6/2/18, Adrien Drouault <adrien.drouault at gmail.com>
 wrote:

 >>>

 >>>  Subject: Re: [NRVR-Members] Anyone Ever Use
 RCS Motors?

 >>>  To: "NRV Rocketry Members" <nrvr-members at server2.nrvr.org
 >

 >>>  Date: Saturday, June 2, 2018, 2:33 AM

 >>>

 >>>  Correct me

 >>>  if I'm wrong, but isn't Aerotech
 the

 >>>  "hobby" arm of RCS?

 >>>  On Fri, Jun 1, 2018 at

 >>>  11:35 PM, Thomas Tweeks Weeks <tom at theweeks.org>

 >>>  wrote:

 >>>  Just

 >>>  curious if anyone's ever used these
 motors?

 >>>  https://www.rocketmotorparts.

 >>>  com/

 >>>

 >>>  Chris

 >>>  Maier?

 >>>

 >>>  Very

 >>>  interesting stuff..  Looks like all research
 and DIY based

 >>>  stuff.

 >>>

 >>>  Tweeks

 >>>  ______________________________

 >>>  _________________

 >>>

 >>>  NRVR-Members mailing list

 >>>

 >>>  NRVR-Members at mail.nrvr.org

 >>>

 >>>  http://server2.nrvr.org/

 >>>  mailman/listinfo/nrvr-members

 >>>

 >>>

 >>>

 >>>  --

 >>>  --Quid quid latine dictum

 >>>  sit altum viditar.

 >>>

 >>>  ______________________________
 _________________

 >>>  NRVR-Members mailing list

 >>>  NRVR-Members at mail.nrvr.org

 >>>  http://server2.nrvr.org/
 mailman/listinfo/nrvr-members

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 >>>

 >>> ______________________________
 _________________

 >>> NRVR-Members mailing list

 >>> NRVR-Members at mail.nrvr.org

 >>> http://server2.nrvr.org/
 mailman/listinfo/nrvr-members

 >> ______________________________ _________________

 >> NRVR-Members mailing list

 >> NRVR-Members at mail.nrvr.org

 >> http://server2.nrvr.org/
 mailman/listinfo/nrvr-members

 > 

 ______________________________ _________________

 NRVR-Members mailing list

 NRVR-Members at mail.nrvr.org

 http://server2.nrvr.org/
 mailman/listinfo/nrvr-members

 --

 --Quid quid latine dictum
 sit altum viditar.

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