Nose cone altimeter bay

Has anyone put a barometric altimeter in a nose cone before? I thought I had a solid design for my rocket and realized (at the end of the project) that I need a sample hole for my altimeter. The av bay is a 54mm mmt inside of a loc 3" NC and I need to put a hole in it somewhere withough making it one giant whistle or cause things too much turbulence. Any suggestions other than buying a timer.

Cut a 3/4" switch band off the main tube and put the holes there - through the cone shoulder. Hopefully enough shoulder left to still work as a nose cone. Shear pin cone if needed.

Mount 2 allthread into a wooden bulkhead, epoxy that into the tip of the nose cone, and treat it like a regular altimeter bay.

Matt

There's no reason you can't drill a hole in the nose cone. I suggest about half a caliber above the shoulder/BT joint.

If you're interested in another design for a nose cone electronics bay, see my Plastic Nose Cone Mods video.

It works as John says. Never have had a problem (for sub-Mach flights).

I have a vent hole in the shoulder of my nose cone, actually there are three, but I use the hole to access my altimeter switch.

Granted this is for a much smaller rocket (Quest Minotaur, 2.6" dia) and it's not yet flown (so I may be in for a big surprise) and I'm a complete rookie here so I make no claims that this is well done, but I thought I'd share my solution to this same problem...

One static vent is just barely visible above the shoulder - Actual distance is about 1/4" away, hopefully this isn't too close!


Four 2-56 screws hold the equipment sled bulkhead to the nosecone. (The aft sled bulkhead is 1/8" ply.)


Equipment sled holding an Entacore AIM USB altimeter. (Thanks again Papa Tango!)


Bottom side of the e-sled with a pocket for a 180mAh, 2S LiPo battery. I still need to make up a cover plate and some foam to secure the battery in place and a magnetic switch to turn it on and off.


Here's what the inner bulkhead on the NC looks like - this is 1/4" ply (overkill) with nyloc nuts epoxied to the back side.


Since the equipment sled will be directly attached to the shock cord (and no additional nose weight is required) the mass of the plastic nose cone is kept to a minimum and (hopefully) unlikely to pull away from the bulkhead after ejection. I plan to do a few flights with the altimeter just logging data (single/motor deploy) but I'd like to eventually move this up to DD using the motor at apogee and a cable cutter to open the main chute.