[BProckets] Tubelesses - report

[flint hapirat]

Launch report guys, 

3 motors (same BP for all, of course) were made per
category:

1. 5% water only
2. 5% water + 5% dextrine
3. 5% corn flour (corn starch, basically) + 10% water 
4. 5% potato starch + 10% water

A standard 10gr BP "batch" was added with the additive
and mixed in a mortar and pestle until no clumps were
visible. The mix was taken and added with water and
mixed well, before ramming. Each motor was rammed into
my "star pump" after the pump was greased lightly with
WD-40 to ease the release.  
Motors were left in direct sunlight to allow fast
dehydration, for 2hr. Before flight the motors were
attached with a pasta straw and a single black match
fuse folded at the end (my thin fuses are 1mm ID). 

Corn starch and potato starch added tubelesses would
not come out of the ramming mold with only 5% water.
Even with 10% water it took a lot of effort to force
these out of the tube. 

In pervious experiments the water added mix did the
best – perfect flights and very energetic burn, while
the dextrine didn’t burn as good (slow burn) and very
slow flight. 

This time the water bonded tubelesses all catoed on
the stand!!! (mini crossettes effect – nice, but
annoying).
The dextrine ones did very nicely – 2 gave a
wonderfully high apogee flight and one was a bit
sluggish (why?)
The corn flour and potato starch both gave the same
result: 1 cato and 2 perfect flights. 

The difference form the previous results I had could
be due to the following:
1. My ball mill has been changed and upgraded and now
the milling is more efficient, resulting in a more
powerful BP.
2. The water contents differ. Back then I used more
water in the previous experiments, but I didn't
measure the volume as I was adding and testing for
cracks in the grain. I didn't have a metal tool and
the grains were somewhat weaker/softer. With my new
metal tools this is no problem and the grains are
strong, smooth and very dense. 

So – I will have to:
1. Test higher water content with the potato starch/
dextrine/ corn flour – to ease the release of the
grain from the system. 
2. The BP has improved in quality since the last
experiments, which may also be a factor.


Well that's all for now...
Cheers,
Flint

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