Pieced together budget compressor setup.

[shenion]

It started with this:

(actual compressor removed). Craftsman 5HP, 20 gallon, 9.2 CFM @ 90 PSI. Was a decent compressor. It is probably 15 years old and still going strong. Was leaking a bit of oil but found case bolts were all lose.

On Craig's list I saw a 60-gallon (227L) 6.5HP compressor for sale with a blown pump $60. One of those crappy oil-less compressors where motor/pump is one unit. Picked it up, another Craftsman; was hoping to save motor. But crankshaft is actually part of motor.

So took the compressor/motor off old one, welded up a base plate (bad pump only needed a 8" square plate.) Drilled and mounted pump and motor. Only hard part was bending the alum tubing and getting the right compression fittings.

Fired it up. It took 5 full minutes to get to 120PSI. I calculated it at 13CFM. Not bad for an old pump. Now comes the problem. IT IS BIG. No room.

So now comes the real cost Move it under the back deck. House is cantilevered 2' out in that area, just enough room to fit this. Used old tailgate from trailer as a base with concrete pyramid blocks.

Even managed to fit the old cover over the belt/pullys:

Now the expensive part: armored cable for power and copper tubing. Used A/C 5/8"OD soft tubing and silver-based solder, should be good as A/C normally has 200PSI (compressor is only 125 PSI).

Ran inside with 2 taps: one with oiler, another straight (runs to separate filter/reg and hose reel on opposite side of garage.)

12 fittings and adapters added not including the valves and galv pipe, 15' of pipe. With the wire was about $80 . Would love to put ports in other parts of garage, but copper is expensive.

Have reel in front of garage between doors:

Probably about $350 invested. The compressor/tank was under $200. Not bad, a decent compressor with this rating is about $1k,

Works well but took me 2 years to get here

Fired it up, no leaks. Then I could hear it echoing off the neighbors house. I added some egg crate foam behind it, should be better. Now have room, a nice setup, and quiet in garage.

 

[scarecrow]

That a nice looking set up for that kind of money shenion

 

[malcolm]

That's a very good price. Mine was that plus the cost of as new compressor plus another 100 feet of copper pipe .

Not quite finished yet, but works (so will probably never be finished). I've got a couple of compressors in a little compressor house outside the workshop.



Only one outlet in the workshop (I've got the reg and filter the wrong way around). But two lengths of rubber hose to connect to 15m if I need.



And the shotblasting kit in another workshop (cabinet still needs gloves and the blaster still needs shot).

 

[Luke]

Here's my contribution to the collection of tanks and copper pipe.

£15 of ebay, 300L tank, needed new inspection port seals, i made them from some rubber sheet.

Manifold for connecting my 50L compressor and the big tank to the regulator. copper pipe and compression fittings - which leak, but not much, they're isolated anyway.

I've also got a fridge compressor plumbed in, but Roger's your man when it comes to them!!

 

[Mikey D]

so how are those solonoid valves wired in then? could of saved your self a small fortune by using end feed or yorkshire fittings

cheers mike

 

[shenion]

I was tempted to use compression fittings as it makes changes a bit easier. They are expensive though.

Malcom: is that a reg/filter and oiler or a second filter. I have been tempted to add another filter after the reg as the air cools at the pressure drop. Seems to be a no-win situation, have before reg and it protects reg from crap; after reg and it works better.

Luke: nice setup. Double solenoids just in case they leak? I bet that small compressor takes forever to fill that big tank.

I still want to add another ball valve at the compressor. Have to empty tank if I need to change something. I think I'll add a solenoid if I can find one cheap. Would be nice to flip a switch rather than running outside.

Well done setups. I bet they are some who don't want to show their kludged plumbing Have seen some things that are unsafe (i.e PVC pipe.)

 

[malcolm]

Malcom: is that a reg/filter and oiler or a second filter.

Just a filter. Flatmate pulled it out of a skip because it was brand new and looked useful. Looked up the website and it would have been quite expensive to actually buy.

 

[Luke]

I used compression fittings as i don't have a torch. Yes, they make alterations much much easier!!

The fridge pump fills the big tank in about four hours, I switch it on for a few hours when i'm in the garage to keep a reasonable amount of air in the tank, if i need a lot on-demand, the other compressor gets a work out.

Double solenoids because i was trying to get away with a cheap bodge. They're washing machine valves, and the valve only closes in one direction, the other direction is always open to flow, hence two back to back, to get a true "open" and "closed"

The project involves an I/O board on the PC, some pressure sensors, and a program to calculate 'time remaining at current output pressure', etc, and to switch the small fast compressor on as necessary, whilst maintaining a healthy duty cycle, so i don't cook the thing.

The gui got this far (ignore the numbers, they're non-sensical text for testing the font size etc (hmm just looked, maybe not completely 'nonsensical))

and the circuit got this far

But then i hit a few problems.

A) the valves don't like opening with a small pressure differential across them - I'm going to use ball valves moved by lead screws - i get proportional valve opening then too.
B) I can't find any connectors for the pressure sensors, which are silly-small UNC thread, i think.
C) I started my final year at uni.

 

[Luke]

did i scare everyone off?! sorry!

 

[malcolm]

I was hoping someone would ask what your contraption actually does. Is it to do with charging up lots of big tanks at night when the electricity is cheaper? From your description sounds like it shuts the air off when you most need it. Or maybe gives you new air?

 

[Luke]

Not specifically.

The main reason is that the compressor on the 50L tank is very noisy, but also gets rather hot. On the other hand the fridge compressor will run all day, is practically silent, and has a PC fan plonked on top of it, which keeps it nice and cool.

I'd happily run just the fridge pump, but that won't keep up with heavy demand, the system will/should detect that, and kick the big pump in for a short time to get the supply up, before the pressure at the regulator drops.

The alternative would be to switch in more fridge pumps - as Roger's doing, but i've only got the one at the moment. need to collect more freezers.

Of course, since the project is shelved, i've been getting by, by just manually turning the fridge pump, or the big compressor on,to meet demand. It's annoying to do though, when most of the hardware is ready and waiting to go.

 

[Robotstar5]

Hi Luke,
Have you seen this site, www.audon.co.uk they have some nice small HMI with built in PLC, we have a couple at work. Software is free download so you can play before you buy.
Regards, Stuart

 

[Luke]

Hi stuart,

thanks for the link, they look nice.

Coincidently, I'll be playing with the siemens Simatic HMI when I leave uni at start my first job, I'm looking forward to it.

 

[Robotstar5]

Hi Luke,
Most of our machines run on Siemens S7 300 PLC with TP170 HMI, (found out this week it's been superceded by TP177)
All our Robot welding cells are networked so the (Dutch)manufacturer can monitor / modify programs without expensive site visits.
Regards, Stuart

 

[Luke]

I expect i'll know a lot more about the S7 300 and TP170 when i start work, they're what i think i'll be using.

Does all your hardware come through your robot manufacturer? or do you deal with anyone in the UK?

Heard of a company called HMK?.....

 

[Robotstar5]

Hardware from various sources, Robot spares from UK agents (Fanuc & Reiss), electrical & pneumatic consumables (sensors, valves etc) from local factors, Siemens spares direct, robot welding equipment from Germany as they are near our parent company so transport is "free"!!

 

[Luke]

hmm, ok, cheers.

 

[arkangel06]

nice setups