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Mar 20, 2010. 11:17 PMCoolerman
says:
Geez guys!! ya want a vaccum pump?? 30"hg vaccum? try fridge or freezer compressor. KISS-- keep it simply stupid.
Mar 14, 2010. 7:08 PMnytrick
says:
Is it possible to leave one of these as positive pressure and make the other into the vacuum? Thus positive and negative pressure in one device.
In this particular pump the two are independent and could be operated in this manner.
Feb 7, 2010. 7:44 AMDillyDog
says:
I'm wondering if this would create enough of a vacuum for a small, i.e. 5litre degassing chamber for molding and casting purposes. Any ideas?
I have posted another vacuum pump that will perform the task that you require...
Feb 7, 2010. 12:43 PMmnpazan
says:
To de-gas mold rubber you need around 29 inches of mercury. Most DIY casters I've seen use vacuum pumps made for air conditioning repair.
Feb 9, 2010. 2:58 AMvotecoffee
says:
As a note, I'm getting the idea you want to use this for a vacuum brake booster. This pump would be aweful for that purpose. There are other electric pumps that may work for your application, but the biggest problem you will run into is inspections and the like. And in all honesty, brakes are not the place to skimp on fixing car. If you're taking an old gas car and modifying it to be an electric car, consider looking at pumps designed for this purpose. But if you really wan, there are instructables to turn a 12 volt air compressor into a vacuum pulling device as in this one: convert a tire inflator-type air compressor into a v…. But do make sure to pull a vacuum into an empty chamber as a kind of buffer for large and sudden vacuum pulls, and run the pump with a cutoff switch so that when a sufficient vacuum has been pulled it will shut off and not burn itself out. You can find a good vacuum switch for cheap at all electronics that is adjustable, or pull them off of an old diesel mercedes benz at a local junkyard (look in the climate control system hidden behind the dash, 80's and earlier are the best to find these in)
Feb 7, 2010. 9:47 PMdaffster13
says:
Wouldn't it be easier to just reverse the polarities on the electric motors? It works in RC's. But i'm just a simple kinda guy
Feb 8, 2010. 6:24 AMwperry1
says:
These fish-tank air pumps run straight off of A/C power so there is no polarity.
Great Ible.
Great Ible.
Feb 8, 2010. 8:20 AMvotecoffee
says:
Electric car motors do have polarity though, and reclaiming power uing the electric motor is done in some applications. But it does not work well as a stand-alone break device. Not enough control over amount of braking nor enough stopping power by itself.
As a note, you can also regain electricity with an AC motor, even easier because no polarity swap, but storing power needs it separated first when using batteries or the like, say using a full bridge rectifier. However, the fish tank-style pump does not have the ability to turn air pressure into power.
As a note, you can also regain electricity with an AC motor, even easier because no polarity swap, but storing power needs it separated first when using batteries or the like, say using a full bridge rectifier. However, the fish tank-style pump does not have the ability to turn air pressure into power.
Feb 7, 2010. 9:17 AMvotecoffee
says:
DO NOT USE THIS FOR BREAKS ON A CAR. Even if it could reliably pull enough vacuum, which is doubtful (there is a slow vacuum build time), this kind of pump is not designed for that kind of strain. Failure would be likely and very dangerous.
Feb 9, 2010. 2:40 AMstatic
says:
An electric car would require a "volume" tank for the brakes in any case, a large enough tank this pump could work, using an inverter to power it. Anyway a higher vacuum reading doesn't necessary mean more power. It's the atmospheric pressure that makes the vacuum hydraulic brake booster work or any vacuum actuator. Around 12 PSI as sea level as I recall. Having said all that a more substantial vacuum pump would be a good idea. Or design the hydraulic system so a booster isn't needed. I once had a 71 Chevy pickup with front disk brakes, and no booster. The brakes on it didn't require that much effort.
Feb 8, 2010. 12:07 AMMacka
says:
I think [sincerely hope] he is talking about a model car, not a full size car. It certainly would be insane to use it in a real car or even a toy car that can carry people!
Feb 9, 2010. 2:50 AMvotecoffee
says:
I think static is right and he is referring to using it for a vacuum brake booster, since an electric car does not have a manifold vacuum pressure to act as a brake booster. Not necssarily fatal if it fails, but definitely not good either. And again, my response still applies, these motors are not strong enough/designed for that level of strain.
Feb 7, 2010. 9:58 AMEllexis
says:
I concur, using this for BRAKES on a vehicle would result in BREAKS!
Feb 8, 2010. 2:50 AMjoel
says:
I think he means using the vacuum hose to clear air in the brake fluid line, during a brake repair, in place of using a hand vacuum pump. I don't think he means to use this for stopping a car!
Feb 8, 2010. 8:26 AMvotecoffee
says:
If that is the case (and I hope so) it can be used for brake bleeding, but take note, it should not be used to pull fluid directly but only to pull a vacuum. By having a separate vacuum chamber inline with the pump and the brake system, such as a jar and the intake for the vacuum clear of the fluid level, it could still pull fluid from the brake lines without sucking it into the pump itself.
It would probably work for actually moving the fluid as well, but I advise against this since brake fluid would quickly corrode the rubber and plastic parts inside of the pump, leading to a quick break down.
Also, since fluids are much more viscous than air and these pumps are designed to work at relatively low resistance and high speed, it would also burn out the motor pretty fast. So even pumping water (which would probably not hurt a good quality pump with strong seals) would be a bad idea.
It would probably work for actually moving the fluid as well, but I advise against this since brake fluid would quickly corrode the rubber and plastic parts inside of the pump, leading to a quick break down.
Also, since fluids are much more viscous than air and these pumps are designed to work at relatively low resistance and high speed, it would also burn out the motor pretty fast. So even pumping water (which would probably not hurt a good quality pump with strong seals) would be a bad idea.
Feb 8, 2010. 8:29 AMvotecoffee
says:
As another note, if you're going to use it to flush brakes, it's even easier than nmodifying the pump at all. Just take any air source such as a tire pump, tape it in the center of say two plastic bags, and use a strong rubber band or something to hold it on top of the brake reservoir. The positive pressure will push fluid out of the lines and help resist air coming back in. Not a lot of pressure is needed here, and if a strong but not too strong rubber band is used, it will even bleed out pressure from the top so that the plastic bags don't break. This makes a great on the fly brake bleeder that uses stuff that you can ptrobably find in your car anyways. you can always use tape or string instead of a rubber band, etc etc.
I don't have a concept of how much 8-10 inches of vacuum is... Would this be enough for vacuum forming small objects? Or for vacuum clamping surfaces being glued (ie veneer on wood)?
Feb 9, 2010. 2:51 AMstatic
says:
5- 8-10-29 inches of Hg the force will always be around 14.7 PSI as sea level. The force available will change with altitude and the weather
Feb 7, 2010. 9:55 AMbikerbob2005
says:
take a length of clear tubing put one end into a bucket of mercury put thumb over end of tube lift tube 10 inches .feel it sucking your thumb? mercury has a sg of 13.6 ergo same tube in water would need to lift 136 inches.
is this right?my old VW had a vacuum storage system i still can not wrap my mind around storing vacuum.
is this right?my old VW had a vacuum storage system i still can not wrap my mind around storing vacuum.
Feb 9, 2010. 3:07 AMstatic
says:
All a vacuum storage system does is to insure a vessel in evacuated enough so the air on the non-atmosphere side of of a servo has a place to go so the servo can work.
A full vacuum that is removing all atmospheric pressuse is about 28 inches. that translates into 14 psi. 8 inches is Not really enough for vacuum forming. I have done crude vacuum forming with a shop vac, which is probably the same suction but larger volume than this thing will do. What works really good is to take an air compressor and hook up a hose to the inlet side. then just open the tank drain and let er rip. My compressor made this easy because the inlet air filter screwed in with a pipe thead, so I just removed it and screwed in a hose barb.
Thanks, everyone! I'll have to see if my compressor is capable of this. It's only 2 gallons, and not rated for continuous duty...
10 inches of mercury is is about the same suction as that of a vacuum cleaner but the displaced volume is much less. It is a fairly light vacuum by industrial standards.
It would take a prohibitively long time for this little pump to remove the volume of air for a bagging operation.
A larger pump like a refrigerator compressor will produce at least 27 inches of mercury and if that is used to evacuate a larger tank like an old propane cylinder first, your bagging or vacuum forming operation will work much better. There are plans available for this type of system on-line here at Instructables.
It would take a prohibitively long time for this little pump to remove the volume of air for a bagging operation.
A larger pump like a refrigerator compressor will produce at least 27 inches of mercury and if that is used to evacuate a larger tank like an old propane cylinder first, your bagging or vacuum forming operation will work much better. There are plans available for this type of system on-line here at Instructables.
Feb 7, 2010. 7:22 AMalantihor
says:
You should be cautious if trying to use a refrigeration or air conditioning compressor to pull a vaccuum. These hermetic or "tin can" units are designed to have the refrigerant in direct contact with the motor windings. The refrigerant acts as an electrical insulator for the windings, as well as a coolant. When run into a vaccuum, arcing can occur inside the case and the motor can start to overheat.
I've seen a larger hermetic compressor take out a large transformer when it was mistakenly started up while in a vaccuum.
It can be done, but just be aware of what you're doing to the motor inside.
I've seen a larger hermetic compressor take out a large transformer when it was mistakenly started up while in a vaccuum.
It can be done, but just be aware of what you're doing to the motor inside.
Feb 7, 2010. 9:18 AMvotecoffee
says:
Awesome instructable. Great idea. Will have tones of uses. Thanks!
Thanks.
Feel free to post some of your ideas for low vacuum uses.
Feel free to post some of your ideas for low vacuum uses.
I use it for handling electronic components as part of a home-made pick & place machine. The small pitch components are not easily placed with tweezers.
I also use it for vacuum sealing electronic components.
I also use it for vacuum sealing electronic components.
Feb 7, 2010. 7:58 AMgbeth
says:
i think this will get down to 2 or 3 torr... good enough for my mercury vapor laser!
thanx bud for the tutorial!
thanx bud for the tutorial!
Feb 6, 2010. 12:10 PMtazmaniac_37752
says:
About the second pic here the small O ring is close to the rubber hing, is this the way it should look when your putting it back in?
Yes, This picture shows the pump body in the vacuum position.
Feb 4, 2010. 4:02 PMstruckbyanarrow
says:
On the first picture does it say retard after 120 psi?
Sweet! Is it just me, or do all of us Canadians live in a vacuum?
I would have to say yes. But Canadians definitely do not suck...
By the way thanks for the compliment coming from the most requested machine on the net...
By the way thanks for the compliment coming from the most requested machine on the net...
Very effective at picking up surface mount stuff. Say, where did you get the little suction cup you're using?
The tip is from a small tool called Handi-Vac which I got with a micro-controller starter kit. It is also available from several electronic tool retailers on-line. One that has it is http://www.howardelectronics.com/virtual/products.html
I hope that this helps.
I hope that this helps.
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