Page 1 of 3

Opinions on 12v compressors

Posted: Mon Feb 18, 2008 1:06 pm
by lockmanslammin
I'm wondering what you guys think about those 12 volt compressors meant for the cigarette lighter in your car? They all seem to have around a 250PSI rating. Honestly they just seem to cheap to actually pull that pressure off. I need more pressure though. Also I was wondering if anyone had links to old threads about DIY high pressure pumps. particularly the pistons in them. I've used the search function without much luck here.

Thanx for any info in advance. Lock

Posted: Mon Feb 18, 2008 1:12 pm
by jon_89
i would suggest a shock pump.

Re: opinions on a certain type of compressor

Posted: Mon Feb 18, 2008 1:20 pm
by Ragnarok
lockmanslammin wrote:Thanx for any info in advance.
And your grammar had been so good until then. :D

My opinions can largely be read here:
http://www.spudfiles.com/spud_wiki/inde ... Compressor

They tend to do around about the pressures they claim, but provide a dribble of air, and tend to have a life expectancy shorter than a tactless and foul mouthed drunken English football fan in a Welsh bar full of less than sober rugby players.

In that region, a shock pump is one option, but you really do need to look at homemade track pumps.
I'm not sure of a link myself. I've made one, and thus never had to do the search personally.

Re: opinions on a certain type of compressor

Posted: Mon Feb 18, 2008 1:29 pm
by lockmanslammin
tend to have a life expectancy shorter than a tactless and foul mouthed drunken English football fan in a Welsh bar full of less than sober rugby players.

HAAAHAHAHAHA

Posted: Mon Feb 18, 2008 1:44 pm
by lockmanslammin
jon, I have a pretty large chamber for a shock pump, although I still may get one and just use it to top off with, not sure yet.

Posted: Mon Feb 18, 2008 4:25 pm
by Hotwired
What isn't said there and is usually in small print on the compressor packaging/leaflet is that their duty cycle sucks.

Last time I had a peek at one it said something along the lines of 30 mins of rest for every 10 mins use...

You could probably beat it to 300psi with a shock pump and you can certainly beat one to fill a tyre using a manual pump.

Posted: Mon Feb 18, 2008 4:39 pm
by POLAND_SPUD
you can try this --> http://www.spudfiles.com/forums/my-comp ... 11866.html

It has several advantages over shop compressors and those cheap 12V compressors
main advantages:
+ quiet
+ high pressure - up to 30 - 35 bar ( but I use 20 bar most of the time)
+ dirt cheap - (if you can get the main part/pump for free)
+ easy to make
+ relatively good flow when compared with 12V compressors ( 70 cm X 1.5 chamber filled to 300 psi in less than 30 seconds)

disadvantages:
- apparently those refrigator pumps/compressors are quite expensive in the US (you can try to ask at a junkyard for them they should have it much cheaper)


to sum up - it is ideal compressor for high pressure/low chamber volume (about 500cc) guns

Posted: Mon Feb 18, 2008 10:13 pm
by DVLCHLD
For pressurizing pneumatic devives I recommend a CO2 tank with a remote line and a home made fillstation with a regulator and a quick disconnect fill nipple to connect the remote line to. You'll have all the air you need at 850 psi and it will pressurize as fast as you want it to.

Posted: Tue Feb 19, 2008 1:54 am
by Gippeto
Poland_spud,

I checked your link, but could not find answers to my questions.

What is the longest you have run your compressor?

How much heat does it build up?

Do you think you could run it 4 hours non stop?

I have 3 of these so I am really interested in your answer.

Thanks.

Posted: Tue Feb 19, 2008 12:18 pm
by POLAND_SPUD
it was about 45 minutes of continuous work...

As you probably know when air is compressed a lot of heat is produced... the problem is that these pumps don't have in-built fans or radiators since they were not designed to work as high pressure compressors in the first place...
of course heat builds up much slower than in 12V compressors but I think that they would overheat when working for more than 1hour without brakes...I've noticed that it heats up much slower during the winter so it could work maybe half an hour longer...

overheating is not the problem for me as I ussualy pump the gun to 300 psi for 25 - 30 seconds, then I turn the compressor off, load ammo and fire the gun - so everytime there is 1 minute brake before it is turned on again... this way I can shoot for several hours without any problems of overheating

if you want to run it continuously for 4 hours you have to add some sort of cooling system......
I suppose that you can try:
* soldering metal sheets to the metal casing of the compressor in order to form radiators... (yeah I know it is easier to say this than to acctually do this)
* using computer fans ( when combined with radiator it will work for sure)
*putting the whole compressor/s in a container and filling it with oil so that it can transfer heat to the oil.... (possibly the best solution; esspecially if you are planing to use all three at the same time and becasue the metal casing they are enclosed in is filled with oil)
*putting a wet rag on compressor (works fine but I admitt it is the most ghetto way of doing this)

I am curious why do you need them to work for 4 hours you're building an uber pneumatic from 5 meters long 12" pipes or something ? :D
Could you write where did you get them from, becasue lots of peple have problems with finding them in US and UK for reasonable price ?

Posted: Tue Feb 19, 2008 12:53 pm
by Ragnarok
POLAND_SPUD wrote:*putting a wet rag on compressor
'ere, are you saying I'm wet? :D

My eyes pick "Rag" or "rag" out of any post quite quickly now, regardless of whether or not it actually refers to me.

Posted: Tue Feb 19, 2008 1:09 pm
by jackssmirkingrevenge
POLAND_SPUD wrote:*putting the whole compressor/s in a container and filling it with oil so that it can transfer heat to the oil.... (possibly the best solution; esspecially if you are planing to use all three at the same time and becasue the metal casing they are enclosed in is filled with oil)
sounds good :)

Posted: Tue Feb 19, 2008 1:27 pm
by POLAND_SPUD
@ ragnarok. uhmm no, not really... :?

I have new signature for you --> " some say that if he were a women he would get wet whenever he talks about H.E.A.L. or high pressure" :D

@JSR yeah that was my inspiration...

Posted: Tue Feb 19, 2008 2:15 pm
by Gippeto
If I were to use all 3, I would not have to run them 4 hours. 4 hours was a figure based on using only one. I would add a storage tank, pressure switch, overpressure release valve, and I suppose a temperature switch too. It's either this or regulated nitrogen, which I have to pay for.

They weren't cheap,...I had to buy the whole acreage to get them! :lol:

Posted: Wed Feb 20, 2008 5:14 pm
by POLAND_SPUD
what is the capacity/volume of the tank ?
I'll try to post a vid of this working soon...