VACUME CHAMBER

[SCOTT EVANS]

OK
I just finshed the a ruff completion of my Vacume chamber. I built it out of 1/4″ plexi glass. About $60.00 worth. I say ruff, because, I still need to clean it up, and cover the electrics, so I dont get zapped again. 8) I was a little worried, the barrowed parts out of the food saver, my wife was going to give away, were not going to be up to the task. Not only did they work, but measuring with the altimeter, I barrowed out of my Air Plane, at 5000 feet the pump drew down a 1000 foot increase in 5 seconds. At 10,000 feet, it was about 8 seconds, per thousand feet. 🙂 I had to stop at 11,000 feet, because I heard a noise 😯 (A Snap even though I renforced it with suports inside). I was hoping for 15 or 20000 feet but Im not ready to impload this thing yet. I would actually like to test some altimeters, since thats what I built it for. 🙄 Ill post some pictures when I figure out how!

scotte

[Jeffrey Joe HintonModerator]

Breathing apparatus necessary above 25,000′ – apply now to the TRA BoD if you’re planning on going over the established waiver limits. Unless you’re like the late Sir Edmund and can rough/tough it out. We’ve got General clearance to 20K. Beyond that, ask permission of the BoD and hope all of our paperwork is in order.

[Bruce R. Schaefer]

A vacuum chamber? Please, this whole project sucks! 😉 Notice the altitudes Joe mentioned… there’s no wonder why this guy gets elected Prez year after year.

[SCOTT EVANS]

Breathing apparatus necessary above 25,000′ – apply now to the TRA BoD if you’re planning on going over the established waiver limits. Unless you’re like the late Sir Edmund and can rough/tough it out. We’ve got General clearance to 20K. Beyond that, ask permission of the BoD and hope all of our paperwork is in order.

I said 15 or 20,000. Besides the waiver I have other things to worry about, note the Far Regs.

91.211 Supplemental Oxygen

(a) General. No person may operate a civil aircraft of
U.S. registry —

(1) At cabin pressure altitudes above 12,500 feet (MSL) up to
and including 14,000 feet (MSL) unless the required minimum
flight crew is provided with and uses supplemental oxygen for
that part of the flight at those altitudes that is of more
than 30 minutes duration;

(2) At cabin pressure altitudes above 14,000 feet (MSL) unless
the required minimum flight crew is provided with and uses
supplemental oxygen during the entire flight time at those
altitudes; and

(3) At cabin pressure altitudes above 15,000 feet (MSL) unless
each occupant of the aircraft is provided with supplemental
oxygen.

And above 15000 I have to supply all the passangers with oxygen. I may have to get a stronger vacume pump, to pump out all that oxygen I have to pump in!
😯
Scott e

[SCOTT EVANS]

I tested one of my new Missle works Altimeters today. Not Bad. Made three runs in the vacume chamber. Started at 5000 feet (since thats our altitude here) and took it strait to 10000 each tilme. I come to find out, alot of my home made matches are duds (not the fault of the altimeter). Again just seem to snap the tip off. Any way, the last time both matches lit properly.
I let go of the pump button when the airplane altimeter hit 10,000. A second later the droug match lit. I bled pressure off, well I mean, I let pressure back in to the chamber slowly, and the main match lit close to 6000 right where I set it at. Way Cool! 8) Funny the Missle Works Altimeter reported 5034 feet all 3 times (maybe it measures in multiples or somthing). Hmmmmm. Well any way, not bad I guess. Pretty accurate. 34 feet give or take. The AirPlane altimeter isnt certified, so it might be off 50 foot or so. Its pretty neat to see the match light right where it supose to, up close and personal! 🙂 I still need to clean it up and finish some of the details but it does exactly what I wanted (checking and testing a rocket altimeter against another readable Altimeter in a fairly controled environment). See Pictures at the linc below.

http://good-times.webshots.com/photo/2590174110102900583UxrADB

[SCOTT EVANS]

Breathing apparatus necessary above 25,000′ – apply now to the TRA BoD if you’re planning on going over the established waiver limits. Unless you’re like the late Sir Edmund and can rough/tough it out. We’ve got General clearance to 20K. Beyond that, ask permission of the BoD and hope all of our paperwork is in order.

You know Joe
To try and take this thing to 25,000 MSL, I might be left with a pile of Plexyglass splinters! Use your saefty glasses!

Scott e.

[Conway StevensParticipant]

Yes do use safety glasses. In fact I would have recommended to use even thicker material. I use 1/2 and 3/4 inch thick Lexan/acrylic when I vacuum process my propellants and even then I end up with more or close to 3/8 inch deflection in the surface. Im running at 28″ and with 5cfm down to 40 microns.. So it can be scary. Just be careful.

BTW each of the missile works stuff is all calibrated by vacuum chamber. In fact a very expensive highly accurate 100,000 ft + capable one.

[SCOTT EVANS]

Yes do use safety glasses. In fact I would have recommended to use even thicker material. I use 1/2 and 3/4 inch thick Lexan/acrylic when I vacuum process my propellants and even then I end up with more or close to 3/8 inch deflection in the surface. Im running at 28″ and with 5cfm down to 40 microns.. So it can be scary. Just be careful.

BTW each of the missile works stuff is all calibrated by vacuum chamber. In fact a very expensive highly accurate 100,000 ft + capable one.

DUDE, Way beond what im doing! Although I thought 1/2″ would have been better! Especially since we cant get that transparent aluminum from Star trek 4 yet. I dont even know what a micron is!

Scotte 🙂

[SCOTT EVANS]

BTW each of the missile works stuff is all calibrated by vacuum chamber. In fact a very expensive highly accurate 100,000 ft + capable one.

Nice to know! First time I heard of that one. Im just worried about getting back $500.00 rockets and $100.00 electronics gear!

Scotte

[Bruce R. Schaefer]

I dont even know what a micron is!

Scott, a micron is a very small moron, or a millionth of a meter.

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