loading

Make a manual vacuum pump for under $20 by converting a bicycle pump

Featured
Picture of make a manual vacuum pump for under $20 by converting a bicycle pump
A vacuum pump is just an air pump that you use for sucking rather than blowing. You can convert an old-fashioned "floor pump" ("bike pump") into a vacuum pump that can take over 75 percent of the air out of something. That's several times as strong as a vacuum cleaner's pull, and three quarters as strong as the best possible vacuum pump.

The net atmospheric force on whatever you evacuate will be over 11 pounds per square inch (or over 1500 pounds per square foot), which is enough for many tasks requiring vacuum.

(For those of you who are not metrically impaired like most of us in the U.S., that's over 7700 kilograms per square meter.)

Some examples:

(1) Vacuum pumps made this way are in use around the world, in non-industrialized areas, for vacuum packing food. (Especially to save seeds for the next year's planting, by killing bugs and preventing germination. See http://www.plenty.org/soy/vacuumpump.html )

(2) A manual vacuum pump can used to make a "vacuum press" to clamp laminates together with a ton or more of force while the glue sets. (A smaller manual pump, designed for evacuating wine bottles, is often used for laminating skateboard decks, using a commercial vacuum bagging kit from Roarockit called the "Thin Air Press". Our bigger pump pulls about as hard, but requires considerably less pumping.) It can also be used for vacuum bagging composites like fiberglass, to squeeze out excess resin and make stronger, lighter parts.

(3) You can use it with a vacuum former, to form thicker plastic sheets than you could with just a vacuum cleaner. (Doug Walsh shows how to apply this to vacuum forming in his book "Do It Yourself Vacuum Forming for the Hobbyist," available from http://www.build-stuff.com )

(4) You can implode various things with it, or attach it to a vacuum chamber and expand or explode things in the chamber; that's often fun and/or instructive. (Try Peeps.)



The vacuum generated is not strong enough for some tasks, like evacuating refrigerant systems or degassing difficult-to-degas liquids. For those tasks you need a pump with more leverage, that takes almost all of the air out.

A plain bike pump is just a piston pump rather like a syringe, with a rubbery disk sliding in a cylinder. Drawing back the disk sucks air into the cylinder, and pushing it in pushes air out.

To make this syringe-like thing work as a pump, sucking from one place and blowing to another, two "check valves" (one-way valves) are used. One lets it suck in from an air intake, but not blow out the intake. The other lets it blow out the exhaust, but not suck in from the exhaust.

Unlike most piston pumps, a bike pump uses the rubbery disk both as a piston and as one of the check valves. When you pull back on the pump, the disk flexes inward and allows air around it, into the cylinder ahead of the piston. When you push inward, the disk is stopped from flexing the other way by a metal disk (like a big washer); its edge seals against the inside of the cylinder, so that when you push it down, it compresses the air in the cylinder and forces it out the exhaust.

(There's a normal check valve at the exhaust, to keep it from sucking the air right back in on the upstroke, and more air flows in behind the piston through a hole in the cylinder top.)

To convert the pump, we'll need to do two things:

(1) Reverse the piston disk and the metal disk that backs it up, so that it seals on the upstroke (to create vacuum) and flexes on the downstroke (to let air around it and out of the cylinder).

(2) "Reverse" the exhaust check valve, so that it lets air in but not back out, and we can use the old exhaust connection as the new air intake. Actually, it's usually easier just to remove the check valve, and replace it with one that does the right thing, so that's what we'll do.

To make it easy to do both of these things, we'll want a simple, cheap, old-fashioned bike pump with no frills (like a pressure gauge) to complicate things.

(If you want a small electric vacuum pump, have a look at my other instructable on converting a 12V "tire inflator" air compressor: http://www.instructables.com/id/E791HNXF23Z39P6/ )

 
Remove these adsRemove these ads by Signing Up

Step 1: Get the right pump, and a few other cheap things

Picture of Get the right pump, and a few other cheap things
bp2vp178autoweb.jpg
The crucial first step is to get the right pump---a simple old-fashioned one of what used to be the standard design. I got a Slime brand 2060-A at Auto Zone (an auto parts chain store) for $10, and it's perfect.

You want a simple cheap pump with:

(1) a shaft that's a metal rod about a 1/4" or so in diameter, not a 1/2" plastic tube

(2) a cylinder top that unscrews, or can be released by unscrewing a few small screws

(3) a rubber disk and metal plate that are held onto to the end of the rod (opposite the handle) with a nut, so that you can just take them off and reverse them

(4) a metal fitting where the hose attaches, with a six-sided base, which unscrews like a nut. This is both a hose barb for attaching the hose, and a check valve we'll need to gut

(5) reasonably long throw and reasonably large diameter (for a bike pump); a skinny pump will be slower, and

(6) no pressure gauge. Pumps with pressure gauges often use a different kind of check valve, and have air space around where the gauge attaches that may affect how much vacuum you can pull once the conversion is done. (You can fix those things, and I have, but it's easier just to get a no-frills pump.)

If you have an Auto Zone nearby, go look for a Slime 2060-A "Floor Pump"; it's cheap and you'll be all set. Otherwise, look at the pictures in this instructable, and try to find a very similar pump.

(I have no connection to Auto Zone or Slime, and no reason to think that other brands aren't just as good, but if you use exactly the same pump, you should have zero difficulty following the directions.)

Looking for a "floor pump" at an auto parts store is a better bet than looking for a "bike pump" at a bike shop.

You'll also need:

(1) Three or four feet of 1/4" I.D. braided PVC hose. (Lowe's sells it by the foot in the plumbing department, for about 30 cents a foot, so you'll want a dollar or so's worth.) That's a kind clear flexible tubing with braided reinforcement; small diameters stand up very well to vacuum, unlike some other small hoses.

(2) A check valve with hose barb ends to fit 1/4" I.D. tubing. McMaster-Carr sells these online. Mine cost about $4.00. (Part number 6079T53 from http://www.mcmaster.com )

(Some people use an aquarium check valve, which costs about $2 at a pet shop. I tried that and mine leaked, as well as restricting flow a little more than I like, but some people are happy with them. If you go that route, you'll need to use smaller-diameter hose to connect it; let me know how it works out for you.)

(3) A small hose clamp. I got mine for 25 cents at a local tool place, but you'll likely have to buy a 2- or 4-pack at most hardware or auto parts stores, and pay a dollar or two.

You'll also need few tools:

(1) An adjustable wrench, or a non-adjustable one that fits the hose fitting on your pump.

(2) Something that can cut thin metal, such as tin snips, a nipper, a hacksaw, or a rotary tool. (You might be able to get by with a file and a pair of pliers, or even just some needle-nosed pliers.)

(3) (maybe) a power drill with a 1/8" drill bit suited for drilling a little bit of metal, or for the 2060-A, a screw and a screwdriver.

Rags or paper towels are good, because you'll be dealing with greasy things.

Step 2: Reverse the piston disk

Picture of Reverse the piston disk
bp2vp172autoweb.jpg
bp2vp174autoweb.jpg
bp2vp175autoweb.jpg
bp2vp166autoweb.jpg
To reverse the piston disk, unscrew the cylinder top, and pull the handle out all the way, so that the the piston disk comes clear of the cylinder---be careful, it's greasy. You don't want to lose the grease and get it all over other things, so prop the shaft up with something to keep the piston disk off your work area. Have paper towels or something handy.

Notice that the piston disk is actually a shallow cup shape, with a lip around it. That lip flares out and seals against the cylinder on the downstroke.

Now

(1) Unscrew the nut on the end.

(2) Pinch the rubber and metal disks together, and pull them off the end of the shaft.

(3) Turn them around.

(4) Put them back on the shaft.

(5) Replace the nut and tighten it up, hand tight.

Now you need to get that stuff back in the cylinder, and you don't want to scratch the piston disk on the sharp inside edge of the cylinder, so:

(6) Pinch the rubber disk from the sides, into an oval shape,

(7) Angle the shaft and the disk about 30 degrees relative to the open end of the cylinder, and insert one end of the oval, and

(8) Gently work the rest of the disk into the cylinder, pushing it inward anyplace it seems to catch on the edge, and straighten the shaft.

Now you can wipe the nasty grease off your fingers.

(9) Push the handle in some, straight, and

(10) Screw the cylinder top back on.

You're half done.


Step 3: Remove the hose fitting & hose from the pump

Picture of Remove the hose fitting & hose from the pump
bp2vp179autoweb.jpg
Now use a wrench to unscrew the hose fitting from the base of the pump.


Step 4: Remove the hose from the hose fitting

Picture of Remove the hose from the hose fitting
bp2vp187autoweb.jpg
bp2vp188autoweb.jpg
The exhaust check valve is in the hose attachment fitting; you need to gut it so that air can flow freely into the pump through it.

But first you need to get the hose off, to get at the fitting to modify it.

There is a piece of thin metal crimped around the end of the hose, to clamp it onto the fitting. You need to get that off, so you can remove the hose. Cut the thin metal with tin snips, nippers, a rotary tool, or whatever you have available that can cut thin metal. (You might even be able to tear it apart with a small screwdriver and needle-nosed pliers, with some effort. Pry and bend and tear it apart bit by bit.)

Once you've got the crimp off, work the hose off the fitting. You'll find a "hose barb" there---a hollow cylindrical bit that sticks up into the hose, with a flared part to help it grip the hose from the inside.







Step 5: Remove the check valve parts from the hose connection fitting

Picture of remove the check valve parts from the hose connection fitting
bp2vp191autoweb.jpg
bp2vp196autoweb.jpg
Now examine the hose fitting carefully. There's an oval cavity inside it, and a little metal ball that can move back and forth in that cavity. When it gets sucked toward the pump on the upstroke, it makes a seal, but when it gets blown toward the hose on the downstroke, it doesn't. This lets air out, but not in; it's what's called a "ball check valve," and it's built right into the hose barb fitting.

(You probably can see the ball, just barely, when you tip the hose barb down... it rolls almost to the end of the hose barb, and stops short when it hits a couple of extra bits of metal, which partly block the end of the hole.)

To get the ball out, you need to make the hole as big as the ball all the way to the end of the barb.

The straightforward way to do that is just to drill it with a 1/8" drill bit; just drill down into the hole to take away any extra bits of metal that retain the ball, and you can roll the ball right out.

For my Slime 2060-A, it was easier than that. I noticed that there were a couple of slivers of metal on opposite sides of the end of the hose barb, which had just been bent inward to make the retaining parts. All I had to do was bend them outward again.

I did that by inserting a screw into the end of the barb, and turning it with a screwdriver while holding the fitting with a wrench. The threads of the screw gripped the two bent-in pieces of metal and pulled them outward enough to make room for the ball to come out. (For other pumps of a generally similar old-school design, you may have to drill the hose barb to make the hole big enough to release the ball.)

Once you have the ball out, check to see if you have a hole clear through the fitting. There may also be a piece of rubber in there that needs to be removed. In my case, I tapped the fitting on the table a few times, and a little piece of rubber just fell out.

If you have a different brand of pump, you may need to drill yours to tear up the rubber, and blow the bits out. Drilling straight through fitting is not difficult, and may be a good idea anyway, if you want to go to the trouble. (See the next step.) Whatever kind of check valve is in there, drilling right through it is bound to help remove it.

Step 6: (Optional) Drill the hose fitting out a little

Picture of (Optional) Drill the hose fitting out a little
I decided to make the hole through the hose fitting a little bigger, to reduce any resistance to air flow.

This doesn't make much difference most of the time, because the resistance there is usually small relative to how hard you have to pump anyway, for any substantial vacuum level. It does make rapidly pumping larger volumes of air at lower vacuum levels slightly easier. (Like near the beginning of evacuating a vacuum bag or the vacuum tank for my vacuum former.)

At any rate, I just drilled through the existing hole with a 1/8" drill bit. As usual with drilling metal, you should to do that in little spurts, at fairly low RPM's, and frequently pull the drill out to get shavings out of the way and let the bit cool. This took about a minute of drilling in several goes spread out over a few minutes, drilling from either end while holding the fitting firmly with a wrench. (I used titanium-coated but very cheap drill bit from Harbor Freight.) If you drill too fast, or for too long, you'll just heat things up and dull the bit faster.

Once you've drilled it, blow the metal shavings out. You don't want them getting in the pump.






Step 7: Screw the fitting back on the pump

Picture of Screw the fitting back on the pump
Screw the hose fitting back onto the pump, and tighten it hand-tight with a wrench.

Step 8: Attach the hose and the new check valve

Picture of Attach the hose and the new check valve
bp2vp206autoweb.jpg
bp2vp207autoweb.jpg
bp2vp211autoweb.jpg
Now cut a short piece of hose, about an inch or so long, and fit it over the hose barb. The piece of hose should be long enough to accommodate the barb, and the barbed end of a check valve, but not much longer. (Maybe a quarter of an inch extra.) Any extra space between the pump and the check valve will reduce the vacuum level you can pull, so don't use a long piece of hose here.

If you're using 1/4" braided PVC like me, the hose will probably fit well enough to make a seal, but not tightly, and it's a good idea to put a hose clamp around it. That will ensure that it doesn't lose its seal, and that it doesn't slip off. (Under vacuum, it probably won't lose its seal because vacuum will suck it inward onto the barb; if it slips off, though, you're hosed.)

Now attach the new check valve to the barb:

(1) Make sure the arrow on the check valve is pointing TOWARDS the pump, so that it will allow air flow INTO the pump, but not back out through the intake.

(2) Insert the appropriate end of the barb into the litttle piece of hose. It should be snug; work it in most of the way.

Once that's done, you can attach the long remainder of the hose to the other barb, in the same way; the other end is what you attach to whatever you're sucking from.

Now you have a vacuum pump. Try it out.






1-40 of 73Next »
shortshift7 years ago
Thank you for posting this recipe! I was able to draft a vacuum pump quite simply and with the bagging equipment found at Aerospace Composites, I put together a pretty good system for some fiberglass layups that I'm working on for my motorcycle project.

Here's a fuel tank prototype that I've been working on. I used a check valve from what appears to be a fish tank setup (ACP was the supplier). 1/4" neoprene tubing.
IMG_1369.JPG

Thanks for share article about EVP Vacuum Solution! - Vacuum Pump,Vacuum Systems,Vacuum Parts,Vacuum Valves

drcrash (author)  shortshift7 years ago
Very nice. Keep us posted. Maybe you should do an Instructible on low-end vacuum bagging. I think a lot of people would be interested.
drcrash (author)  drcrash1 year ago
And here's shortshift's Instructable on Basic Vacuum Bagging:

http://www.instructables.com/id/Vacuum-bagging-basics./

Cool.
ya mean that hasn't been done yet? wowzers. I'll see about putting something together. Of course I'd cite your vacuum solution as a means to the end :)
drcrash (author) 8 years ago
Apparently this instructable is the "hack of the day" over on www.hackaday.com; cool. A question came up over there about reversing the exhaust check valve rather than replacing it with the one from McMaster-Carr. You COULD do that, and I'm pretty sure it would work fine. (With the Slime 2060-A, anyway.) You could clean the oils off the exhaust hose fitting and the place it attaches, and epoxy it in backwards, with the hose barb pointing into the threaded hole. (You might need a spacer such as a large nut to keep the hose barb from sticking all the way to the bottom of the threaded hole; I'm not sure.) Then you'd need to epoxy a new hose barb on top of that. (Hot glue would probably work, if you duct tape the hose to the cylinder near the joint, to avoid stressing the joint if the hose gets pulled on.) That would let you make a vacuum pump for around 13 dollars with stuff from the auto parts store and a home improvement store, and not have to wait for mail order.
chuck.clarke3 months ago

Instead of the valve from McMaster-Carr or the fish store, you can get a vacuum check valve at the same auto parts store where you get your pump. It's in the "Help" parts area (Dorman is the manufacturer) and the one I got ran about 5 bucks at AutoZone or O'Reilly. Saves you from having to order the darn thing and pay shipping on it, and it's actually built for holding vacuum. It may have a little more restriction than that other thing, but sometimes you need something available. I just finished building the Vac pump in this "Instructable" and I was easily able to pull enough vacuum for the testing I use here at work. I need about 175 mmHg to test the instruments we work on, and this was WAY better than the converted soccer ball pump that died the other day. It took me about 45 minutes from disassembly of the foot pump to a working vacuum. Yes, I can truly say that this thing SUCKS... hahahahahhahahahaha!! (sorry..)

JohnnieC9 months ago

Thanks for share information about <a href="http://www.pumpair.com.au/thomasvacuumpumps">air vacuum pumps</a>

rotarycontentpics.png
bnasty9411 months ago
Can this run 25 psi I need a pump that can but don't want to spend a lot of money.
bnasty9411 months ago
Hey man would this be able to get 25psi in a vac chamber that's the minimum I need please get back thanks
DanTDM1 year ago

Even ones with a metal shaft usually don't work! So, I just used my pump as a portable source of air for my air gun

Skymeat1 year ago
I love it! Taking an old one apart now.
can anyone help me build a vacuum pump using a foot air pump with pressure gauge?
WazIt2 years ago
Thanks, I'm going to try it, but I'm going to use a tire valve stem with my vacuum chamber so I can use the hose that comes with the pump
WazIt2 years ago
Thanks, I'm going to try it, but I'm going to use a tire valve stem with my vacuum chamber so I can use the hose that comes with the pump
wily702 years ago
Hello, how much Hg or bar can I expect from such a vacuum pump?
thanks
xfrench2 years ago
Hi. Thanks for the inspiration. Any advice for how to use a found pump that does have a gauge? It's the first one I've found thrifting, and would be nice to put to use...
Geoluhread3 years ago
Will this effective for a physics experiment? I would want to use this for a Bell in a Jar experiment for our project. I've tried this already I don't know if there is something wrong but the air sucked is very little. I used an aquarium check valve because its hard to find a check valve like yours in our place. I've searched for every autosupply and hardware store and they don't have it.
gatan6 years ago
hellooo all
question -0,6bar=....."mercury
help me, how to convert :) thank..
Esmagamus gatan4 years ago
onlineconversion.com does all you need.
Derin gatan5 years ago
-17 in Hg
arisecute gatan5 years ago
Please go to - http://joshmadison.com/software/convert-for-windows/ - you would get a free conversion software for download. Madison is a great man doing a great job.
Use Google. Type: "-0.6 bar in mercury" and press "enter". That works for most conversions, such as "3 feet in meters", "5 pounds in kilos", etc.
Hi, i recently discovered a how-to on building a kitesurf board. It requires vacuming to (i guess) squash the fibreglass cloth onto the core, ans seal it all nicely. I was a little put off by this as i have no means to do it, (conventional vacuums are too expensive to buy just to make a board) but now im wondering if it is possible. Would the vacuming capabilities of this pump do the job and pull all the layers in enough to hold it together strongly?? any help on this would be awesome and much appreciated
Find an old refrigerator thrown in the trash.

Take the compressor with control box out by cutting all the tubing. Fit a power cord on it and you'll have one side sucking air, other blowing. There's your vacuum pump.
Eddie_T4 years ago
I confess I am somewhat of a nut, my wife has been hospitalized on occasion and I collect the oxygen and IV tubing when it is changed. Just for kicks I made a small vacuum pump using the tubing, two of the locks that permit injections into the IV line and a syringe. It might be used to take the air out of a wine bottle or one of those 2.5 inch cylinder thingies.
CHRISPB6 years ago
Does anyone have a suggestion on makeing a manual pump that could, after several priming pumps, begin to generate a constant airflow of say 10-15 L/minute? Would you use a flywheel or double valves?
Goedjn CHRISPB4 years ago
Build a double-action bellows, or two sets of foot-bellows, feed the output into a big sack, and put an appropriately sized rock on the sack. This is essentially how a pump organ works.
The SYNer5 years ago
would this pump work for a particle accelerator
no a particle accelerator needs a near perfect vacuum something no simple hand pump can get near. to make a a vacuum for a particle accelerator you need a cooling system near absolute zero to literally freeze the air solid on the cooling pipe making it a better vacuum than space.
Wafflicious6 years ago
My cup imploded(I think that's a word..)
Yes, it is a word and means according to the built in dictionary on my Mac, "verb, to collapse or cause to collapse violently inward"
MadMonso4 years ago
Hey, although McMaster doesn't seem like you can do direct links you can, just do "#"{PartNumer} no "" or {} so Check valve: http://www.mcmaster.com/#6079t53 That one specifically just does a highlight on a page so I'd still include the part number in your description. Nice job.
wenui5 years ago
Hi,
How do you use like valve?
Thanks
vernonen5 years ago
G'day all,
I am about to build a vcuum bubble to use as a VTOL transport  and OH hoist. I needed an economical vavuum pump which would pull out 80% of the air. Has anyone tried this? I will keep posted.
Will this work well for making neon lamps and other such devices?
Derin7 years ago
lol,"if the pvc hose gets off you are hosed",oh the irony
tradergordo7 years ago
I was about to build one of these, thanks for the instructible, but I just discovered that Harbor Freight now sells a vacuum pump for just $10.99 that pulls 28.3" mercury! I can't build one for that cheap, and it creates a very strong vacuum all with standard fittings so you can easily attach whatever you want to it. Can also be used to service any time of air conditioner. Anyway, just thought others reading this thread might be interested. It does require an air compressor so its only for people who already have an air compressor.
HF vacuum pump

They have two other models which are very similar but have different fittings.
Come to think of it - I wonder if someone without an air compressor could just hook a normal (NOT reverse flow) bicycle pump to the air inlet of this HF vac pump and create the vacuum manually, this should be a very easy mod. But I guess it would basically just be the equivalent of using the thing as a giant check valve :) I guess if you live close to a harbor freight store it might be worth trying.
Mine made a scraping noise,is that a prolem? Also I don't reccomend an aquarium check valve.
1-40 of 73Next »