Instructables
video Make a High Volume Manual Vacuum Pump
This video will show how to make a vacuum pump, a device that can be used to suck the air out of sealed environments. This is the same pump I use to operate my vacuum cannon seen here: http://youtu.be/CVL99yIB3NQ

A clear vacuum chamber such as the one seen in the video can be obtained by purchasing a bell jar and vacuum plate, easily available online. I highly advise that only vessels made for handling vacuum pressure such as bell jars be used with this or any vacuum pump. If a vessel were to fail while under vacuum the implosion can be powerful enough to cause injury.

This pump is capable of generating pressures of 29 in/Hg.

Vacuum Pump Parts:
16" of 2" PVC Pipe
20" of 1 1/4" PVC Pipe
2" End Cap
1/4"x1/8" Brass Hose Fitting
3' of 1/4" Vacuum Line
1 1/4" End Cap (x2)
1 1/4" Diameter O Ring
2" Coupling
2" x 1 1/2" Reducer
3" x 2" Adapter
3" x 4" Closet Flange
4" of 3" PVC Pipe
10" of 3/4" Dowel
Self Tapping Screws
Bearing Grease

Okay, so I'm absolutely confused as to what's going on with your vacuum gauge you've got there. From what I've managed to gather, higher values are actually a higher pressure when speaking about this, unless it's indicating vacuum relative to atmospheric pressure. Which I suppose might make sense... but the fact that it goes to 30 makes me question whether or not this is possible... Ugghhh, I don't know...

NightHawkInLight (author)  furrysalamander7 months ago
The gauge measures vacuum relative to external pressure (in this case atmospheric pressure) which is the only way to do it. The standard measurement is in inches of mercury, which basically means if there were a vertical straw in a bowl of mercury and the vacuum on the other end, the vacuum would be determined by how high into the straw the mercury is forced to go by external pressure. 30 inches is the furthest possible travel at atmospheric pressure and equates to roughly a perfect vacuum, though you will never quite get there. Yes, you will be able boil water at room temp, but as the water boils the vapor very quickly raises the pressure inside your vacuum chamber so you will need to keep pumping during the whole process to remove the vapor and restore the vacuum. A manual pump is not ideal for this reason.
Ah, perfect. I think I'll still end up using this because I don't have the money for an actual vacuum pump. Good workout I suppose :3 Thanks for the information!
abennett64 months ago

I'm curious about whether having the second valve on the curved side of the pipe made much of a difference for you in terms of effectiveness. Would it be easier to move the valve in the end cap over a bit to make room for the other valve there as well, instead of on the side?

Some students in my physics class will be making their own vacuum pump and cannon; we'll be sure to share our results once they've finished. Thanks for the instructable!

Okay, I suppose my real question is, can this boil water at room temp? I'm looking into freeze drying for some chemistry experiments.

DanTDM8 months ago

Awesome, but how much did it cost?

EricHi9 months ago
Your list of materials is not really inexpensive, but your design and methods of construction are very ingenious. Thanks for sharing your experiences!
im373311 months ago
Where did you get your container and vacuum plate? I must not be using the correct search terms in Google, all I get are ones that are either industrial (for degassing silicone, also, not clear) or the style you'd see in classrooms, and suggestions?
NightHawkInLight (author)  im373311 months ago
It's a bowl bought from Walmart and doubled up sheets of polycarbonate as the base with sheet rubber in between.
fahadshihab11 months ago
This is the old vacuum pump which I had built for my discharge tube.
jjdebenedictis11 months ago
Any idea how low a pressure you can get down to? I assume if the light bulb filament does eventually burn out, that it's not a very hard vacuum.
NightHawkInLight (author)  jjdebenedictis11 months ago
29in/Hg is my maximum attainable vacuum. Modern bulb filaments will burn out even under extreme vacuum quite quickly because in the low pressure the boiling point of the metal is increased and it evaporates. That is why inert gas is used instead of vacuum in modern bulbs.
sau211 months ago
you are awesome and sub to ya