3 Point hitch air compressor

[hydrovane218]

This is just a quick question regarding pto driven air compressors.This whole question comes about mostly because I have been servicing industrial air compressors for 13 years now and recently bought a 3203 John Deere.
Has anyone not had the need for real(20+cfm @ max 175psi) compressed air out in an area where 230v power is not easily available? ie. using air tools to make repairs out in a field or in a shop where a tractor could get to but without sufficient electricity? If so, have you spent the money and bought a gas driven unit for approximately $2000+?
I did a bit of a search and didn't come up with anyone making anything like this.(If I missed the boat on this one, enlighten me)
I am partially through a build of a unit using a (rebuilt 10hp offshore copy of a good old American pump-because I have enough parts to do this cheaply right now) and figure that at standard 540 rpm PTO speed, this setup will deliver slightly over 20 cfm at up to 175 psi.(All only using approximately 5-7 hp of PTO power. I am thinking that even if I got these pumps new, and not going large scale production(which probably won't ever be necessary), I could sell them for somewhere in the area of $1,400, and with this pump, at that speed, it should go forever.(considering that the gas driven units drive the pumps at around 1,100 to 1,200 rpm.
Just a curiosity that needs to be addressed.

 

[mjncad]

I hope you build if for no other reason than it sounds cool and would make for a neat set of pictures.

 

[J_J]

This is just a quick question regarding pto driven air compressors.This whole question comes about mostly because I have been servicing industrial air compressors for 13 years now and recently bought a 3203 John Deere.
Has anyone not had the need for real(20+cfm @ max 175psi) compressed air out in an area where 230v power is not easily available? ie. using air tools to make repairs out in a field or in a shop where a tractor could get to but without sufficient electricity? If so, have you spent the money and bought a gas driven unit for approximately $2000+?
I did a bit of a search and didn't come up with anyone making anything like this.(If I missed the boat on this one, enlighten me)
I am partially through a build of a unit using a (rebuilt 10hp offshore copy of a good old American pump-because I have enough parts to do this cheaply right now) and figure that at standard 540 rpm PTO speed, this setup will deliver slightly over 20 cfm at up to 175 psi.(All only using approximately 5-7 hp of PTO power. I am thinking that even if I got these pumps new, and not going large scale production(which probably won't ever be necessary), I could sell them for somewhere in the area of $1,400, and with this pump, at that speed, it should go forever.(considering that the gas driven units drive the pumps at around 1,100 to 1,200 rpm.
Just a curiosity that needs to be addressed.

I think you have a great ides . There's got to be a lot of big old three phase high voltage compressors around that most people would not think about. Most people only use their air compressors for a few minutes anyway. High pressure, high volume, sounds like the way to go. Mounted on a frame, direct driven, or a pully setup. My PTO has two speeds, 540, and 850. I like your idea, show some pictures when you have it finished.

 

[Wayne_H]

This sounds like a good idea! I know the antique JD tractors have air pumps for the PTO, but not to the tune of 175 PSI at 20 CFM. How do you plan on stopping the compressor from turning when it reaches 175 PSI? You would need some sort of electric clutch I guess from the PTo to the compressor?

Wayne

 

[LeadPoison]

Just flick the PTO switch.

 

[Wayne_H]

Just flick the PTO switch.

I'm not sure that's a plan, your in the middle of sand blasting, can barely see out your hood, and you need to make sure the pressure does not get over 175 PSI or something makes a loud noise. Or you let it pump up, go to the shed ot get a cold frosty one, and when you get back the compressor is burned out.

You really need an automatic shut off.

Wayne

 

[LeadPoison]

Unless you two people out there. One person operating the pump/pto the other on the business end. Not ideal, but it would get the job done. I don't think it would be a marketable product this way, but for the DIYer it would have appeal.

 

[EddieWalker]

The $2,000 part of it is the killer for me. I have an old trailer that I built for a few hundred dollars that I can haul my gas generator on. This gives me power for my arc welder, my air compressor and electric tools. The generator was around $500 and I have a cheapy $100 air compressor that I use for most portable jobs, but also a good one for bigger jobs.

The thing I like about this is that it's very flexible in allowing me to have what I need, when I need it. Everything is used for other things and not dependent on a tractor that might not even be working at the time. Of course, it is dependent on the genorator working, but if my tractor is broke down out in the woods, getting the generator to work is allot easier then the tractor.

How much air preasure and usage do you need in a compressor for emergancy field work? I can run a 3/4 inch impact wrench with my small, portable air compressor. It doesn't last very long, but with a little patience, I've been able to get it done when I've had to do this.

Eddie

 

[shvl73]

Gas driven compressors don't shut off, they have some sort or by-pass or unloader valve when at max psi.

Check out this old thread:http://www.tractorbynet.com/forums/...-off-air-compressor.html?highlight=compressor
Much lower CFM than your looking for but, if he's even close on the cost, cheap.

 

[bjcsc]

The simplest way to regulate it would be to use an electric clutch (like an AC compressor) and a regular pressure switch. Easy enough...

 

[Rio_Grande]

My gas driven pump has a pop off valve that relieves the excess pressure. It can pop and the pump continue to run without building any more pressure. Don't see why that wouldn't work in this case, but for 1400.00 I would have to see and electric set up.

I paid 300 for my year old compressor. It had a honda engine but only pumps to 150.

That is good enpugh for what I do. I do have a seperate 30 gal tank that I hook to it when I am going to be using the impact or air drill alot.

 

[hydrovane218]

Guys... The pressure would be regulated by a PILOT valve that is connected to head unloaders. Head unloaders, in most cases, are basically a small piston usually attached to a fork that , when they have air applied to them, forces the suction valve open. By doing this, th pump doesn't generate any flow into the tank. (ie. pressure doesn't continue to build)
The compressors that alot of you likely have,(whether or not the store you bought them from has duped you into believing is a 5hp or not) is in most cases nowhere near a REAL 5hp. Rule of thumb is you get 4 CFM per hp at a standard pressure of 90 PSI. Therefore, if you look at any 5 hp industrial air compressor, you will get approximately 20 CFM at 90 PSI.(note that 90 psi is only the standard pressure that most units delivery is compared at and that this unit, like most industrial units, is rated up to 175 PSI)(the higher the pressure, the lower the output flow at that pressure(as these are fixed displacement piston pumps)
I have a 5hp 230v unit in my garage and I know that I can keep it running non stop when die-grinding, using an air chisel etc. This PTO unit would deliver the same flow as my home unit.
I was just trying to get some feed back as to why no-one is manufacturing one of these things yet(that I can see). I am guessing that, based on the replies so-far, the answer might be lack of demand for something like this at the price it might cost. (although it would be considerably cheaper than the same type of unit that is gas engine driven. ie.what transport truck tire service guys use)
I look forward to any more input anyone might have, constructive criticism or positive coments all the same. I have it partially constructed and will take a pic or two soon.

,

 

[tommu56]

I used this when i converter my compressor to gas power


Grainger Industrial Supply: Unloader,Load Genie 4TK14


tom

 

[teg]

We had an air compressor hooked up to hydraulics on a work tractor. Noisy little bugger. Not sure about the brand. We used it to spray herbicides around 20psi. Mainly for small plot work, nothing like you need. It was mounted in the front and supplied air to a 3ph rigged up with a spray boom. That was 15 years ago and it's still being used.

 

[skidsteer.ca]

I think its a good idea, but not one every person would pay for, if they had it they would use it.
I have a 18cfm 5hp 2 stage comp in the shop and a 5.5 hp single stage on my service truck and another 27 cfm 2 stage 12 hp kohler we keep at bush camp. I twin both 2 stage pumps together for sand blasting and the 18 cfm one is the least I would want in the shop, get busy with the da sander or die grinder and I have it running steady.
We got the 2 stage in the bush when we needed a 1" impact to service new equipment. But I never realized how handy it is for cleaning thing. We use a blow gun with a 36" wand and pressure wash with air in many cases. Rads general clean up its just as good as cleaning with water, and I don't get soaked.
The 27 cfm one I wanted a hydraulic motor to drive it off the wet kit on the truck, but it cost more to buy the parts then to buy a running gas unit.

I vote for the load genie or similar unloader system over a electric clutch. There pretty trouble free, no wires required.
I'd be more apt to use a hyd drive unit that would run off my skidsteer, and would like to see plenty of cfm for sandblasting.
There is no such thing as "too much air"
Ken

 

[638]

Guys, 40 years ago I built a portable air compresser using a compresser out of a wrecked over the road truck. Used the air tanks off of that truck also. Those air compressers come with unloading valves and can be ran continusly for ever. Mine was direct coupled to an old two cylinder gas engine.

ron

 

[J_J]

So essentially, you are looking at a compressor that puts out up to 27 cu ft , at 175 psi, PTO drive shaft, an unloader valve, and a tank of your choice and gages, mounted on a frame. I say it can be done, and there are some people that would love to have one for those big jobs. You could sell them as a kit if the price is right, or sell the plans.

 

[DavidPerry]

How about this

Home

58 cfm at 100 psi. $600 plus a donor vw engine

I don't know that I would want 175 psi as I don't have any tools that operate at that range.

 

[skidsteer.ca]

You can always regulate the pressure so you tools always run at the same level. However many people I know run at full pressure, which depending on the cut in point is likely @ 150 psi. Higher pressure shorten the hammering time a impact needs to break a fastener loose, so in that respect it may not be as hard on the tool as you think. You will want to regulate it for some tools such as paint or undercoat sprayers
Ken

 

[thescubasmith]

Wayne...I wouldn't want to stop the compressor when it reaches max pressure. It can be done, but would be much simpler to just use a pressure-relief valve to vent off excess pressure as the compressor continues to run.