What about fridge compressors?

[psycix]

It depends of the dead volume it has. One with alot of dead volume simply cannot compress the gas any further so it will keep running without pumping air. (if the motor has enough power to run it on that pressure)
If it has no dead space (ideal) or just a little, the motor will not be able to keep running it up to that pressure, it will start slowing down, and on that point, you should write down the current pressure and turn it off before it stalls.
If it stalls with the power on, it will burn its coils.

[POLAND_SPUD]

http://www.economatics-education.co.uk/ ... ressor.htm

what can you see mounted on the tank ??

[psycix]

Yep, some commercial compressors indeed look suspiciously much like fridge compressors.
Though limited to 8 bar, it may be worth it to buy one and find out if it can actually reach over 30, as a normal fridge compressor can.

[john bunsenburner]

Yes i have had that idea alot of times, take of the safety valve, plug the hole and see what happens.

[POLAND_SPUD]

well it does prove that they have been used as air compressors... that particular model is for an educational kit for teaching pneumatics so I ma not surprised that it is limited to 8 bar....

I wonder how high pressure one could get from a 'regular' shop compressor with a safety valve and pressure switch removed... something tells me that many members would do a lot to get that 50 or 100 psi more

[john bunsenburner]

Yes big time, some one should try, but check that chamber first before you end up making a bomb....

[psycix]

Well, the shop compressor I own which is limited at 8bar does not sound like having much trouble for the last part, which means the motor is powerful enough to power the pump further.
I noticed that most of the parts are rated to 12 bar. The air tank, the regulator and everything is rated to 12.
I might take the shell off and see if I can remove the limiting factor.

[POLAND_SPUD]

the limiting factor is a safety valve and pressure switch... you might consider getting them rated to higher pressure (like 15 - 20 bar)

[Ragnarok]

That's not the real problem... Pushing it too far for too long puts the motor at some risk of burning out.

12 bar it might handle without permanent damage, but I wouldn't recommend pushing it any further.

[JDP12]

Yea I'm with rag here... it can burn out, so really why bother trying to push teh limits of it? Just find its limit, stick to it, and if you want more, get some CO2.

I think it'd be a lot cheaper and easier than trying to push the compressor to get as much possible out of it.. just not worth it in my opinion but its up to you

[POLAND_SPUD]

co2 is by far the cheapest gas you can get... in the USA.... however not all of us live in the USA or UK....
paintball is not very popular in europe so CO2 is quite expensive...


besides.... you have to buy a reg, presure hoses cappable of high pressures and CO2 itself.. so it's quite expensive esspecially if one does not live in the US/UK

[psycix]

CO2 is quite expensive compared to air.
On top of that, the weight of the gas reduces the performance of your gun.

[john bunsenburner]

Use a bulk air tank or scuba tank, if you build the gun strong eanoth you could even use it un regged, and if you rent the tank+regulator it is not that expensive. I live in switzerland so no other contry can beat my prices

[POLAND_SPUD]

That's not the real problem... Pushing it too far for too long puts the motor at some risk of burning out.

I was acctually thinking of lowering the RPM to get more torque (you know gearing it down (or up??))


the only question is - will the compressor handle higher pressures? well I think you can't answer that question without doing some tests (of course taking all safety precautions)

this idea is just a suggestion you know... I am happy with my fridge compressor so I am not really interested in this personaly...

[jimmy101]

Well, the shop compressor I own which is limited at 8bar does not sound like having much trouble for the last part, which means the motor is powerful enough to power the pump further.
I noticed that most of the parts are rated to 12 bar. The air tank, the regulator and everything is rated to 12.
I might take the shell off and see if I can remove the limiting factor.

That would be a really stupid thing to do. The compressor has a safety factor built in for a reason. SAFETY.

If the resevoir ruptures at 12 Bar it'll likely kill anybody within a few feet.

If you swap out the stock pressure switch for a higher pressure one then what happens ten years from now after the tank has been setting with condensation it?