TDK Propulsion » Knob Motor http://www.tdkpropulsion.com Research 2.0 Sat, 13 Aug 2011 01:53:53 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 New Blue, pt. 2 http://www.tdkpropulsion.com/2010/03/new-blue-pt-2/ http://www.tdkpropulsion.com/2010/03/new-blue-pt-2/#comments Tue, 16 Mar 2010 20:35:52 +0000 David Reese http://www.tdkpropulsion.com/?p=127 This weekend, I ran a 480 load of the new blue at a lower pressure (400 psi instead of ~600 like last time). The result:

Aerotech I357
Aerotech I357T

TDK I300
TDK I300

OH YEAH. The one drawback was that this motor was not nearly as loud and generally “nasty” sounding as the higher pressure one. This was down at a Kn of 180, and operation was completely smooth, coming up to pressure and shutting down cleanly. I like this a lot. I have a 54/1050 and two 38/640s of this stuff ready to go next…

]]> http://www.tdkpropulsion.com/2010/03/new-blue-pt-2/feed/ 0 Carbonate Reds http://www.tdkpropulsion.com/2008/08/carbonate-reds/ http://www.tdkpropulsion.com/2008/08/carbonate-reds/#comments Thu, 14 Aug 2008 07:27:33 +0000 David Reese http://www.tdkpropulsion.com/?p=47 It seems that Strontium Carbonate-based red motors get a bit of a bad rap in the community. The king of these formulations is Pat Gordzelik’s Polish Rojo family of propellants. I originally shied away from making reds, as I believed PR/SPR to be “wimpy” propellants that made a weak red flame, and that real men used Strontium Nitrate to make red motors. But Strontium Nitrate has its problems — it’s highly hygroscopic and needs to be dried and screened before use, and the grains must be kept sealed tightly before flight. I have a few old Kosdon East “Red Rhino” motors that are nitrate based, and though they give a BRILLIANT red flame and a delightful low-thrust, long-burn profile, they are immensely difficult to light due to their age and the amount of moisture collected by the hydrophilic Nitrate groups.

So, I decided to try out Polish Rojo:

Nice flame, Pat! (Photo by SoCal Mad Matt, click for larger version)

Further details on the motor after the jump: This was a 54/1400 load in the venerable Arcas (flight #15, I believe) with something between Polish Rojo and Super Polish Rojo propellant. From my understanding, the only difference between the two is the size of the Magnesium used in the fuel; the Mag in this motor was -800 mesh stuff from Pat, though it was slightly clumpy, so I’m not actually sure what to call it. The motor used 3/4″ cores (since I didn’t have a 5/8″ drill bit with me at the launch to core the motor), so it was probably a very full J motor rather than the usual baby K we get from this case. But still, way cool flight.

Moral of the story: Carbonate reds are reds too!

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