Air Compressors

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StarEcho

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I haven't seen any recommendations for air compressors, so I thought I'd add my own and see if anyone else has their own favorites.

I've used this one for the past 4 years with great success.

51ZMp0yt-lL._SX425_.jpg


https://www.amazon.com/KOBALT-Elect...1597872&sr=8-6&keywords=kobalt+air+compressor

I've used it many, many times on my car tires, trailer tires, and bike tires.  It works for everything.  12Volt  and 120 volt so very versatile.
 

Every Road Leads Home

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I have this one, based on the recommendation from JimInDenver I believe.  I haven't needed it in a real life scenario yet, but I lowered the pressure in my tires as if I were going off-roading and re-inflated them and I was happy with the performance.  Not going to win any speed records re inflating it, but if I'm out traveling, i'm in no rush anyways.  

https://www.amazon.com/Industries-M...711271&sr=8-3&keywords=12+volt+air+compressor
 

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RVTravel

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The MV50 is what Bob uses too I think and is popular in the 4 wheel drive community to raise and lower tire pressure for off roading.
 

highdesertranger

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everybody who travels off the beaten path should have an air compressor.  I tried more than a few 12v ones even a top of the line Viair I found them lacking.  they are slow to pump up truck tires and that's really all they are good for.  you really can't hook them to a tank to have an air supply for air tools and the such they just don't put out enough CFM.  so I put a engine driven one on my truck.

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now I have a real compressor. I can air up a tire in seconds and run air tools.   highdesertranger
 

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Optimistic Paranoid

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I assume that the average person here would have to pay someone else to build an engine driven air compressor for them.  Care to speculate on how much something like that would cost?
 

becida

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highdesertranger said:
everybody who travels off the beaten path should have an air compressor.  I tried more than a few 12v ones even a top of the line Viair I found them lacking.  they are slow to pump up truck tires and that's really all they are good for.  you really can't hook them to a tank to have an air supply for air tools and the such they just don't put out enough CFM.  so I put a engine driven one on my truck.



now I have a real compressor. I can air up a tire in seconds and run air tools.   highdesertranger


Have any details? It's a really good idea...
 

SternWake

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Modified MV-50 owner here. Very happy with it. Nearly 10 years old.

They can use some spit and polish to be turned into a very good compressor as quality control is suspect.

Very easy to disassemble and improve if one is inclined to do so. If not inclined, one should get an allen key and retorque the head bolts anyway.

Most every compressor has a duty cycle. Run only for so long then allow a period for cooling off. If this is not observed then they can turn into noisemaking battery depleters which allow a battery to deflate. Be observant of this possibility.

Part of my modifications included a 80MM computer fan blowing over the head and better heat conduction from cylinder to finned heatsink
 

highdesertranger

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at one time I had three of the compressors that I got for free from junk cars. I put one on my truck, I gave one to a friend, and I still have one. plus I made my own mounting bracket. so right there are the 2 biggest expenses. once you have those it's just a matter of how fancy you want to get. I put one outlet on my font bumper and one in the rear, I also tied it into my air bag system. I also scrounged three air tanks off old portable job site air compressors. I spent just over 200 bucks on misc. parts but that included having the compressor rebuilt, I did this to insure I had a long lasting, fresh compressor. kit's are available for some vehicles, here are some resources if anybody is interested,
http://www.jedi.com/obiwan/jeep/yorkair.html
http://www.offroaders.com/info/tech-corner/project-cj7/project-cj7-onboard-air.htm
http://www.offroaders.com/directory/products/Kilby-AirBoss.htm
https://www.cuoffroad.com/product-lines/complete-airboss-kits/
highdesertranger
 

SternWake

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First thing i did was tap the Head for standard 1/4" NPT fittings, instead of the metric threads they used. I hated the screw on tire chuck provided with the unit as my airbags would lose several PSI unthreading the chuck. Also it incorporated some method for quick releasing of pressure, but I found it hard to keep it from releasing pressure unintentionally, and would have to hold it or finagle it while running to keep it from doing so.

I have a bunch of photos but MFing photobucket is acting up, again, so perhaps later.

I put on a new tighter raduis more flexible coiled air hose and a locking tire chuck. I drilled out the part on the plunger on the tire chuck so it cannot build pressure on the hose and quickly exceed the PSI limits of it. This is important, the tire chuck must be passive otherwise it can quickly exceed the max pressure of the unit or the hose.

The Head bolts were barely more than finger tight, and when I removed it I found the sleeve in which the piston and cup slides to generate pressure, was only touching the head's heat sink in 4 small spots, well more like 3. I filled the gaps with high temp grease to help conduction of heat from sleeve to heatsink.

I also added a 80MM computer fan to blow over head.

The wiring into the unit's endcap was horriblly crimped rtogether with no stress relief on the cable. They use crimp nuts for splicing wires and there is a standard bosch style relay inside. I had a newer relay and streamlined all the wire connections and added a stress relief so I could in theory swing the compressor like a weapon from the power cable. I so far have not upgraded the 14awg cable it came with, but I did cut off the alligator clamps and installed anderson powerpoles as I use these all over my Van.

Also, the air filter provided, well there was left over flashing from the mold that was seriously inhibiting airflow into the filter. I spent a few minutes with a razor blade opening the inlet holes allow the compressor to suck in as much air as it can. Do not use the unit without the airfilter. Not only does it make it more quiet, but it is rather amazing how much stuff it will suck inside without it which of course compromises the seal on the piston and will cause it to generate more heat and not be as efficient.

Mine pulls 16 to 19 amps depending on battery voltage.

I will try and post Pics later, If and when Photobucket gets its head out of its festering Hemorrhoid filled ass.
 

Ballenxj

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SternWake

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The endcap of the MV-50 can be rotated.  A bosch sytle relay lays within. I added the stress relief cord grip on the wire exit.  The fan is an 80MM sunon pulled from an old computer.  It is not really all that powerful. I cut up a 120Mm computer fan grill to mount the 80MM fan.

fanmountfromback_zps64c1bb3f.jpg


The sleeve cylinger rides on only 4 spots with air gaps inhibiting conduction of heat from cylinder to heatsink.  I
filled the gaps with high temp grease to help conduct the heat.
airgapandcontactpatch_zpsc6bac6b7.jpg


I bought 3 1/4 NPT taps for cutting new threads in the Head for 6$

https://www.amazon.com/Vermont-Amer...coding=UTF8&psc=1&refRID=CJ02E04R74BA2VW047FW

tapinsidehead_zpsadf58e4b.jpg


I did not drill out existing metric threaded hole, just made sure the new 1/4 NPT tap was as straight as possible:

retaphead1_zps1a26c088.jpg


Here is how the unit arrived, one can see the white crimp nuts where the 14 awg wire enters the back of the unit.  This is so half assed

plasticback_zps37af4c40.jpg


Here is the locking tire chuck I used, and drilled a hole in the plunger to make it passive:
modifyairchucktofreeflow_zpsf6cd0cb2.jpg
 

SternWake

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This is the passive hole so pressure cannot build in the hose.
nipplevent_zps46e54b5c.jpg


Here is why one uses the air filter:
head1050_zps66302e4a.jpg


cylinder_zpsa5cf523a.jpg


The harbor fright yellow airhose was later replaced with a tighter coiled more flexible higher quality 15 foot blue airhose.

https://www.amazon.com/Coilhose-Pneumatics-PU14-25B-B-Flexcoil-Polyurethane/dp/B0037QFGQM


 I used no air hose quick release fittings as I saw no point in removing the hose from the head or the tire chuck from the hose.  Also I was unsure how to make a quick connector passive so it cannout build pressure with motor running and no storage tank.
popthehatch_zps1748ada8.jpg


  I have added some zip ties between handle and fan to keep it from bouncing so rapidly and making a clattering noise when compressor is running.

I did not replace the 14awg cable with 10awg, but it is very easy to notice how much slower the motor runs the lesser voltage it receives.  Drawing 16 to 19 amps will cause a certain amount of voltage drop on 14 awg.  I have some anderson powerpoles more distant from battery than others over different thickness wire, and if inflation  speed is a concern I use the 8 awg feed direct off my battery switch so it gets max voltage.


I have not measured voltage at the relay to check, but other than opening it up occassionally to clean and o regrease the cylinder sleeve and cup with Sylglide, the only other improvement i feel could be easily  made to this unit is a more powerful 80mm  fan closer to the head, or a fan that can directing its flow over the head better like this powerful fan:

https://www.amazon.com/Vantec-Torna...493013240&sr=1-1&keywords=vantec+tornado+80mm

And replace the 14 awg leads with 10AWg and 45 amp powerpole connectors.

I've little fear of overheating my unit/ worrying about surpassing its duty cycle with the improvements I have made, but the sunon Fan is only about 35CFM and its flow is not concentrated on the head.  that 80MM Vantec vornado fan has stereing vanes which concentrate the flow and is very powerful for its size.

Most powerful  of all 80Mm fans:

https://www.amazon.com/Delta-TFB081...id=1493013558&sr=1-4&keywords=Delta++80mm+fan
 

Ballenxj

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DANG SternWake! Did you buy the compressor new, then totally rebuild it right away, or did you use it first before deciding what modifications it needed?
A few more questions, Did it run hot before you added the fan?
Can it now fill a truck sized tire faster, and what size tires do you generally use it on?
With the improvements you made, will it last a lot longer now?
Thanks.
 

SternWake

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I owned it for 7 years before modifying it. I took it apart as I noticed it slowed down, and the reed valves in the head were obstructed with pieces of a plastic bag. When I first got it, before I opened up the inlet holes on the airfilter, I used it often without the air filter. Mistake.

  Once I saw how simple it was made,  I decided to improve it.

Most all of these compressors have a max run time and then a recommended duration of cool off period.  They all would benefit from more heat removal.  Usually when 12v compressors fail it is because they got too hot and melted the rubber/silicone cup on the piston which expands under the compression stroke.

My mods would lkely only marginally improve its speed to fill tires. The biggest improvement in this area would be thicker wire to the relay from the voltage source for less voltage drop.  My unit says 13.5v max but I ignore that.  Mine will get 14.7v at least at the powerpole before the units 14awg wire begins.  Not sure how much voltage  is lost on the length of original 14awg I kept.

Mine was bought for airing up 235/75 /15 tires mostly from 32PSI back upto 45PSI unless on soft sand then I might go lower.  I have slightly larger tires now, 30x9.5x15, My  rear helper spring Airbags go upto as high as 100PSI.  Also my on Demand electric water pump cannot self prime, so I use the compressor to pressurize the 7 gallon reliance tank after filling it to prime the water pump.

I expect the unit will last longer simply because it cannot get as hot with the improved heat conduction and airflow over the head.  I do have a more powerful 80MM fan Whose airflow I might concentrate on the head, but I have not really been airing down my tires as of late so it does not really have a chance to get hot so my need for further improvements are unwarranted.

The Only Mod that I did that I deem a requirement is the locking tire chuck as I so despised the thread on one provided with the unit.  The Airflter's inlet holes being clogged with left over mold flashing should be opened up on purchase.

I've not really perused the newer compressor offerings.  I've had the unit for 10 years now, and would buy it again unless something newer safter better was the same price.

I would not buy any unit with a 12v ciggy plug, Alligator clips, or no deal.

I think mine is actually marketed as MasterFlow MF-1050 Air Compressor, I bought mine in Pep boys in Nov 2007 for 62$ IIRc

https://www.amazon.com/Master-Flow-MF-1050-MasterFlow-Compressor/dp/B000L9AD2U
 
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