Sugar Motor Testing Pt.2, Getting Sweeter

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Art Applewhite's Cinco38 Prototype
Pizza Hut

My Tide Wave version with ISP
38-360 case for comparison

Tide Wave on 1st sugar flight.
Using Ultra-White recipe.

Tide Wave pouring on the sugar
and spinning hard.


A big update to the previous post.
Since that test took place back in February I've burned 3 more sugar reloads in the test series. Since the test stand is still broken [the new guage I want for it aint cheap], I went ahead
and flew them in an Art Applewhite 38mm Cinco Saucer clone, my Tide Wave, or in Art's prototype Pizza Hut Cinco38.
Since it's 1st flight I've trimmed down the wavy edges twice on the Tide Wave. The spin under power was fine by me, but the spinning causes recovery problems. I've also flown the Cincos on an Aerotech G64W reload and an ancient and suspicious single-use Aerotech 320Nt H145 manufactured in 1988. These 2 motors definitely bracket the sugars below in the medium H category.

The motor that blew the stand had Bi-modal KNO3 [an inspecific mix of powdered and granular], my usual opacifier 1% Lamp Black, plus 1% Red Iron Oxide. A very fast recipe.
The next 2 are the same as above but with 8% Titanium shavings added for sparks. One had fine sparks, the other coarser sparks. The mildest recipe, nicknamed Ultra-White, uses granular KNO3 and 1% Titanium Oxide as a white opacifier. The only test recipe not burned yet is Ultra-Pink. Same as Ultra-White above but with the addition of 1% RIO on top of the TiO2.

So far, except for the wrong nozzle incident, everything has worked well. Ignition with my now standard Copper Thermite ignitors has been a non-issue. The RIO sure is messy stuff but it
really does improve pouring viscosity, just as other sugar cookers have noted. I didn't doubt it, but wow, seeing it happen is amazing.

At this rate, I'll have to make more test loads by the time the test stand is repaired.
Aw shucks.

Such a great idea...

Such a great idea, yet even Estes doesn't seem to
want to build one. WTF?
In the 1997 Estes catalog there was a kit that never
reached production. It was a model of a fly-back booster
called Star Booster. It's based on descriptions in Buzz
Aldrin's sci-fi book; Encounter with Tiber. copyright 1996
Great book by the way. I dug it up for this post and then
read it all again.

In the book, the Star Booster is built by Boeing to take
a slide-in Zenit motor/tank assembly, built under license,
in the USA. One or two of them would be attached to a
core vehicle as a strap-on like an SRB is. After using up
it's propellants, the Star Booster would seperate from the
core vehicle then glides back to an automated runway
landing near the launch site. After each flight, the Zenit
is removed for seperate servicing. When the airframe is
ready, the next available Zenit gets installed for a quick
turn-around.
BTW; Boeing really is building licensed Zenits for the
Sea Launch commercial launch program.

The Estes Star Booster model was going to be 18" long,
with a 9.5" wingspan, parachute recovery, C motors only.
By the looks, I expected it to have a cast styrofoam
fuselage over a cardboard core tube, just like the large
Shuttle Orbiter kit of the same time period.

I've been looking at the Estes Star Booster recently  with
ideas for reproducing it. I have hot-wire foam cutting
equipment, so it's not a big stretch for me to model it at
the original size or larger.  The difficult part is that not
only do I want it to glide, I want it to glide with an unfair
chunk of reload casing inside it. In short, a realistic mission
as afly-back strap-on,  boosting a level 2 size rocket.  For
the sake of balance it needs a long thin motor case.  Either
a 29/360 or 38/480+ sized case, probably EX  and burning
sugar. The big trade-off [ya can't design anything without
trade-offs] is, to maintain balance, the bigger the  model,
the longer the motor case needs to be, and  vice-versa.   
Of course, it'll glide like a brick!

For more info see;  Fly-Back Boosters, Reprised
right here at ZZakk's Lab on Monday, May 18, 2009
These 2  posts [of 3 before long] were supposed to coincide
more closely, but I'm easily distracted.

Blue Tube Advancing the Rocket Hobby

The Blue Phenix 4.0

In a recent post to an EX rocket group I belong to,
Randall J. Ejma of Always Ready Rocketry,
www.alwaysreadyrocketry.com made the following
announcements; [somewhat edited.]

Due to amazing demand and positive feedback, ARR has
drastically reduced pricing for Blue Tube! These are
NOT sale prices; these are the new regular pricing!
Check out your nearest dealer first at;
www.whatstyourrocketmadeof.com
Or order directly from ARR. New pricing takes effect
immediately and is almost 40% less expensive!

Also, ARR has recently released;
Six Electronics bays from 38mm to 6 inch, and four new kits
making 5 total.

The moment Randall announced Blue Tube on our group, in
March, I had to post back about whether it would make a
good liner for EX motor making.

The following is the recent post of his test results.
[again, some editing]

Hey guys,
I know a number of you have been asking.
We've gotten some 54mm and 75mm casting tube and liner
sets w/Blue Tube as the liner. We've static fired 2 motors
and flown 1 so far and it has proven to be a far less expensive
alternative to convolute phenolic, it just needs to be thicker
for it to workin a motor design where spiral wound phenolic
isn't good enough.  It just gets too toasty for it.
As a replacement for spiral wound, it seems to work so far,
but when you throw lots of Al and unusually high pressures,
the chance of burn through is fairly high. It would probably
need to be thicker.
I fired a K-550W clone in a Loki case and I could stand on the
liner after firing and it held me up.  Worked perfectly.
But, another test w/a high isp, high pressure, high temp
design that normally only workes w/a convolute liner,
burned through Blue Tube.
Randall

That's a pretty good description of Blue Tube's limits inside a
motor. It appears to fall between the capabilites of spiral
phenolic and convolute phenolic.
I'm curious enough to try some in a couple of my motors
when the sizes I need become available.

One final update; Balsa Machining Service has joined the growing
list of Blue Tube dealers, and is offering laser cut tube slotting of
Blue Tube.

A Really Big Pair

I finished making these 2 nozzles for longtime rocket buddy, Don C., a few days ago.  They aren't the biggest nozzles I've worked on, I once helped design and produce a 2 piece nozzle that was 8" dia., but these are the biggest that I've CAD designed myself and turned on my own lathe.
Eureka! ZZakk's Lab has produced monsters!  Bwa-ha-ha-haaa!!!  

Ahem, in the lower pic they're posed with one of the Cesaroni Pro98 motor cases that they were made for, and the fabulously expensive spanner tool that Cesaroni now sells for installing the retainer rings.  Actually, just about anything you need or want for 4" rocket motors is fabulously expensive. The Cesaroni cases are designed and licensed [fabu dinero, I'm sure] to operate with Aerotech reloads as well as Cesaroni reloads.  This is a good thing since it increases the versatility of the hardware.  My friend however, is currently making his own Moonburn reloads for the cases, and using RCS/Aerotech supplies in the process.  The RCS 98mm nozzles are $44 each for a single use, and in the case of the 5/8" throat on the right, would still need to be custom bored anyway.  My graphite nozzles are completely reusable, and if need be, I can remachine the throats later if they get too crusty, chipped, or a larger throat is desired.  Some internal fuel volume is sacrificed but I added a much better expansion ratio, between 5:1 & 6:1 instead of only 2:1.

Last year, I looked long and hard at the costs of larger motors.  I decided to go with 3" hardware since it costs less than 4" every step of the way, despite the longer length needed for the same power.  Plus, being a hybrid flyer, a 3" combustion chamber is plenty big enough, AND, I'm already used to building rockets that take relatively long motors.

More recently, I rescued a belled 3" case from another friends recycling pile. Thanks RK!  
I trimmed the ends off, but still need to cut new snap-ring grooves.  It's kinda short, but I'm on my way!  When I get around to buying new 3" motor cases, I'm gonna give the
Cesaroni hardware another good look.