AP and AN based composite propellant, candy motors, and N2O based hybrids are allowed at HOTROC experimental launches.
Reminder: EX motors containing the following are specifically prohibited at this site: double base propellants (i.e. AP, Nitroglycerine), use of catocene in excess of 3%, steel casings, liquid fuel motors, zinc/sulphur, black powder propellant. We do not wish to inhibit this type of research but do not have the facilities i.e. bunkers or extreme standoff distances to allow safe firing of those motors at the HOTROC launch facility.
As a group involved in Experimental Rocketry, we want those entering this aspect of the hobby to fly successfully and safely. If you are relatively new to experimental rocketry OR are flying an experimental motor at the HOTROC launch site for the first time, please fill out the following information sheet and provide it to the RSO prior to flying. Although the use of this or any other reasonable questionnaire cannot completely prevent the possibility of motor failures, we believe that it can lower that probability somewhat for new EX fliers. Please don't hesitate to ask questions. The experienced EX fliers all remember the excitement of our first EX motors and are anxious to help.
1. How many EX motors have you tested and what were the results?
____________________
_________________________________________________________________________
_________________________________________________________________________
2. How many EX motors have you flown and what were the results?
____________________
_________________________________________________________________________
_________________________________________________________________________
3. Is this a "mix pac" or standardized formulation? (Y/N)
_____
If yes, was the standard Kn and grain configuration
used? (Y/N) ______
4. What is the basic formulation of the propellant (i.e 80% 200 micron AP,
15% R45HT and curative,
5% Al)? Exact percentages are not required. The
following description would also be sufficient.
(abt 80% 200 micron AP catalyzed by 2% CuO)
_________________________________________________________________________
5. What burn rate modifiers are used? i.e. Copper Oxide, Iron Oxide,
Potassium Dichromate, silver
wire, etc.
_________________________________________________________________
6. What are the initial Kn and approximate maximum Kn for this motor
and how were they determined?
_________________________________________________________________________
_________________________________________________________________________
7. What is the expected pressure and how was it determined?
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
8. a. How many motors were test fired in preparation using the
combination of this Kn and formulation?
____________
b. What were the results? (pressures, thrust, success
or cato or burn thru)
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
9. What is the nozzle throat diameter? ___________ What is the core
diameter? ___________
(What is the ratio of core area to nozzle
area? _________. Why is this ratio important?
______________________________________________________________________)
What is the propellant O.D. _______ What is
the grain length? ______________
(What is the ratio of web thickness to grain length?
________ Why is this ratio
important?
_____________________________________________________________)
10. What is the expected thrust? _________, burn time __________, and total impulse ? ________.
11. What was done to control bubbles in the propellant? i.e. (vacuum
processing and at what pressure,
addition of silicone oil with subsequent mechanical manipulation or the
propellant, etc?) ___________
_________________________________________________________________________
12. Casting and Storage Conditions:
a. What were the approximate temp and
humidity in the immediate environment
when the
motors were mixed and cast? ________________________________________
b. How have the grains been stored?
____________________________________________
c. How long has it been since they were
cast? __________________________
13. Appearance of the propellant?
a. Do visible voids i.e. air bubbles exist
in the propellant (Y/N)? ________ If yes, what size and
how many are apparent?
________________________________________________
b. Did you weight the slugs or cut several
open to test for consistency (lack of voids)
(Y/N)
_________ If yes, what were the results? ______________________________
___________________________________________________________________
c. Did you slice off some of the
propellant and bend it to see if it is flexible or brittle (Y/N)?
________?
Which best matches the flexibility of the propellant (i.e. tire rubber, eraser,
crumbly, silly
putty, brittle,
etc. - and to what degree)? ____________________________
_____________________________________________________________________
d. How spongy and compressible is the
propellant (i.e. chalk, tire rubber, rubber eraser, silicone
rubber or
jello or polystyrene insulation, foam rubber)?
____________________________
e. Is there a good bond between the
casting tube and the propellant (Y/N)?
How do you
know? ______________________________________________________
f. Is any de-bonding or
propellant shrinkage visible (Y/N)? ___________________________
14. How long is the core? _________________________
If you are unsure of item 13, show us some samples. There
are members of the group who
are used to looking at propellant and have personal experience with what
constitutes useable physical
characteristics. They can also coach you on improving the
next casting if the propellant
appears to be
too soft etc. for you to risk putting it in your rocket.
15. What is the motor burn time in seconds? _________________________
What material was
used to thermally insulate the case from the propellant?
________________ How thick is this
insulation material?
16. How are the front and back of the motor sealed? (Please sketch and label.)
Name ________________________________ Date _____________________
Certification Level __________ Tripoli Number _____________