Quasar - Do I need air holes?

[PhxRocketeer]

If the Quasar has GPS, do I need to use the barometric pressure to measure apogee? I always feel nervous drilling holes in my finished rockets, so I’d like to avoid it if the GPS gives a good approximation. What do others do?

 

[Scott_650]

If the Quasar has GPS, do I need to use the barometric pressure to measure apogee? I always feel nervous drilling holes in my finished rockets, so I’d like to avoid it if the GPS gives a good approximation. What do others do?

I believe, and I’m sure someone will correct me if I’m wrong, the dual deploy functions are controlled by a barometric altimeter sensor, not the GPS. So yes, you’ll need ports in the AV bay for it to function properly.

 

[cerving]

Yes you do. FYI, I do not know of ANY altimeter that doesn't have a baro sensor, even if it doesn't actively use it for one function or another. Virtually all of them use it to deploy the main chute, at a minimum.

 

[PhxRocketeer]

Got it. Still using engine deployment but that makes sense. Holes it is!

 

[Rocketholic]

If the Quasar has GPS, do I need to use the barometric pressure to measure apogee? I always feel nervous drilling holes in my finished rockets, so I’d like to avoid it if the GPS gives a good approximation. What do others do?

I hear ya! I hate putting holes in pristine tubing unless I have to. The rocket in my avatar turned out fantastic and it's first flight used the eggtimer apogee. When I finished the Quasar and its sled, I made sure the battery screw switch was positioned at the same hole as the apogee. No new holes. The AV bay, which is a tube internal to the main rocket tube but around 3/4" diameter less, has some tiny holes for wires and such so I didn't add any new ones. I'm definitely considering adding a couple small holes in the AV bay though to help the baro sensor.

I'll post some pics in a little bit.

Just added the photos. The 12ga. shotgun shells keep the charges pointed in the right direction and weigh next to nothing. It doesn't take much by way of holes to equalize the pressure in your rocket. The deployment wires exit through holes above the mounting ring which will allow pressure to equalize above and below the ring. Like I said, I will probably add some small 3/16" or so sized holes in the Quasar side of the bay just to be sure there are enough passages for air to move freely.
Maiden flight with the Quasar went well. The interface is awesome!

 

[JLP1]

As a side note there is an HPR best practice to drill a small hole near the top of the air frame below the nosecone or the payload section to vent internal air pressure as the rocket gains altitude. This is to prevent premature separation. Some folks do and some folks don't. That's up to the individual building the rocket.

 

[rocketryfanatic]

If the Quasar has GPS, do I need to use the barometric pressure to measure apogee? I always feel nervous drilling holes in my finished rockets, so I’d like to avoid it if the GPS gives a good approximation. What do others do?

You feel nervous drilling holes into your finished rocket? You actually supposed to drill the holes before painting. You base the size of your holes and how many on the length and diameter of your avbay, do all that during the building process.