LOC EZI 65 Pressure Holes

LOC EZI 65 Pressure Holes

Post by Ji » Sun, 30 Dec 2001 21:48:55



The directions for a LOC EZI 65 call for drilling two small holes in
the body tube 180 apart. I will most likely never fly on anything
larger than an "I" which would put it around 2500'. Should I go ahead
and drill anyway or is this just "overkill" for the lower flights?

Thanks

 
 
 

LOC EZI 65 Pressure Holes

Post by John Grass » Sun, 30 Dec 2001 22:11:46


If you are not running an altimeter, you may not need these at this altitude
but it does not hurt ad them.


Quote:
> The directions for a LOC EZI 65 call for drilling two small holes in
> the body tube 180 apart. I will most likely never fly on anything
> larger than an "I" which would put it around 2500'. Should I go ahead
> and drill anyway or is this just "overkill" for the lower flights?

> Thanks


 
 
 

LOC EZI 65 Pressure Holes

Post by John Gordo » Sun, 30 Dec 2001 23:15:46



Quote:
> The directions for a LOC EZI 65 call for drilling two small holes in
> the body tube 180 apart. I will most likely never fly on anything
> larger than an "I" which would put it around 2500'. Should I go ahead
> and drill anyway or is this just "overkill" for the lower flights?

> Thanks

From what I've heard, holes like that are to prevent your recovery system
from deploying prematurely.   The air pressure outside the rocket is lower
than that inside the rocket, and this action tends to push your nosecone off
prematurely.  I imagine it depends on the size of the body tube, the
altitude you're going to, and how fast you're getting there.  I've never
seen a rule of thumb that governs when you need to start drilling tiny vent
holes in your rockets.  A lot of people tend to do it if the rocket tube is
3 inches in diameter or more, or if they're going over 2-3000 feet.  Wish I
had some sort of empirical data that shows when it's necessary, but when I
asked around last, no one could seem to give me a hard and fast rule.  "When
in doubt, why not do it,  just in case" is what I decided.  Unless the holes
are too large, they won't hurt anything.