altimeter bay vent holes formula

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Well-Known Member
Feb 2, 2003
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I left my RRC2X manual at home and I need to know hte formula to get the diameter of the vent holes. I am not using the RRC2X but a differnt altimeter tommorrow and I forgot to drill the holes an dI dont know the formula. I also need the formula for multiple holes. I tried going to missile works website but they are in pdf formats and I cant get my acrobat reader to work so could somebody please post a reply before 11:00 tommorrow? Thanks!
For an altimeter bay that is the BT60 tubing diameter by 3" long? I don't think that would work. Do you have the actual formula? Thanks!
1. Calculate the volume of the altimeter bay

Radius x Radius x 3.14 x height

2. Single static port = volume / 400

3. Multiple port = Static port dia / (number of ports /2)
Yeah I remember reading about not using 2 holes, always 1 or three or more. Any specific reason? Thanks guys.

P.S. The reason why I needed it so fast was because I was going to launch some rockets this afternoon, but we got rain last night so I don't know if it will happen. Hopefully it will clear up later. Thanks!

Also, I did the formula and it said the size hole i needed was like 0.014 someting something something. That is like 1/64 of an inch. For some reason it doesn't seem like the right size. I mean the hole is so small I don't think it would properly vent it. I don't even have a drill bit that small. I was thinking about drilling a few 1/16 holes or just one 1/8 hole. What do you all think?