This is a follow-up on an earlier post on creating a vacuum chamber for testing
altimeters and other rocket-related equipment. I’ve attached a photo of the
chamber that measures 3” square and 12” long.
Mike Kramer suggested that I make a smaller test version to work out potential
bugs, and it turned out that cutting the grooves in the 1 ¼” polycarbonate ends
for the o-ring seals was more difficult than imagined. Also, it took a couple
tries to create electrical connections through the end to connect a switch.
Unfortunately, the 2nd stage on the vacuum pump isn’t getting as low as
specification. I’m still working on that, but so far achieved about 29 ½” of
vacuum *. I tested a PerfectFlite SL-100 a couple times and it recorded about
102,000’. So, I think that’s adequate for awhile. 😊
The next chamber will be 6” square and about 40” long to accommodate the upper
half of a rocket I’m working on.
This vacuum chamber project has been kind of a distraction to my L-3 project,
but I’m still glad for the time spent. Always fun building something different
and learning more about atmospheric pressure for amateur rocketry.
Richard Dierking
* There are many different ways to denote atmospheric pressure such as PSIA,
Inches Hg, Torr, mbar, and microns. A Torr is 1/760 atmospheric pressure and
there’s about 1 Torr at 150,000’. I have an inexpensive (aka cheap) vacuum
gauge so it’s really only good for low vacuum.
Attachment:
Test Chamber.JPG
Description: JPEG image
