Air Power

Hey guys,

We’re working on getting compressed air up and out to everywhere it’s needed. This means running air lines not only to both metal shops, but also to the wood shop while allowing room for future expansion.

The tormach, powder coat cabinet, sand blasting cabinet, and plasma cutter now how their own designated connection and air filter / dryer. There will also be an air real in each of the metalshops as well as the west wood shop room. For future proofing, we are also adding a service loop in the attic area to allow for expansion to other areas as needed (Patrick already put in a request for outdoor air).

All the air will be distributed from a manifold next to the air compressor. This is where stuff gets a bit more elaborate. Instead of getting the 2nd ingersoll rand air compressor up and running, we’ve decided to use the tank to act as extra air storage to the system that will help keep us from short cycling the air compressor while also reducing demand on the main air compressor.

Also, after we’re working on a way to make the air compressor be more quiet. :wink:

We’ve been making progress on getting all the air lines run but we’ve got a ways to go. Putting in the second air compressor may be something down the line, but things are looking hopeful that the rest of the rest of the metalshop equipment will be up and running by the end of the month.

If you would like this stuff up and running sooner, you are more than welcome to contact me to find out when or how you can help.

Big thanks to Wallis Mead, Dan Kreis, Terrence Laurendine, and James Tennant for all the help!


Well, he’s in luck. There’s LOTS of air outside, and it’s even free!


Great to see the progress! Thanks for all that you are doing!

Har Har


I’m not sure how far along you are but if you place the extra tank in the woods shop there will be less pressure drop between the tank and the point of use. Really not much of an issue but for air heavy tools like sanders, but a consideration.

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Doug only wanted one drop in the woodshop for air tools, but I have no problem leaving one of the tanks in the wood shop since there will be no moving parts on it and should only be seeing dry air.

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Thanks to Devin Halsey, Steve Thornton, Pay, and Davier for helping make a major push on the air system this evening! There is now an air line to the wood shop and all of the air reals are now hung!

There’s still a bit of a short list to knock out, but if we get the air compressor wired up Tuesday, we should be ready to pressure check all the major tools like both plasma cutters, the tormach, and the powder coating equipment.

Here’s what’s left:

  1. Connect the air real in the cold metalshop to the rest of the system
  2. Wire up the compressor
  3. Pressure test the system
  4. Mount the air compressor on rubber pads
  5. Setup the return loop between the metalshop and wood shop
  6. Setup the 2nd air compressor as the expansion tank

Thanks @rustin.atkeisson for leading the charge on this. I was happy to help this evening and I think I speak for many when I say I’m happy to see the metal shop almost fully operation again.

I can’t express how happy, as someone who fought hard for us to be in this space, it makes me every time pull into the parking lot (cheers to off street parking) and see all the vehicles and people utilizing OUR space.


I’ve volunteered to help wire the boost converter to the compressor, but I know there are at least a dozen members far more qualified for this job than me. Does anyone want to step up and take care of that in the next few days?

Let me give a little more detail. Our compressor is made for 240v, and IIRC, our shop has 208v available. We have a boost converter that I’m sure by now Rusty has mounted to the wall between the nearest 208v outlet and the compressor. We need to connect one side of the boost converter to the 208v at a junction box next to the plug, and the other side of the boost converter to the compressor. I understand we have all the materials needed.

If nobody is available, then the space is doomed to have an old, unqualified, colorblind dude do the work. Are you willing to take the chance that the compressor will be blown up and not available until we raise funds to replace it? :face_with_raised_eyebrow:


Bonus points on taking care of the electrical for the air compressor:

Turns out the boost converter for the kilns is a similar setup… So if we can figure out the air compressor, then we might be able to get the kilns going too.

Devon and Christian took a brief look at the boost converter this evening, but I still need to figure out where the conduit bender went to finish running the conduit between the boxes.


If we have 208 1P, why is there concern over the air compressor but not any of the other machines using power? For example, Miller doesn’t list a range of voltages for the Millermatic series of welders, only 240V 60Hz. Is it just because the air compressor has a motor on it? Did we add buck boost converters for all of the machines in the woodshop? Or do they have a difference, 240V, source?

The air compressor has a boost converter on it since we managed to fry the contactor on the previous air compressor (which i think we were at 220v in the old place). The thought was that by feeding the motor the right voltage, we would n’t have another contactor melt down and trash another motor/compressor.

It’d be nice to throw boost converters in for the welders, but since we don’t have additional converters laying around, it’s not something I’m making a priority to get done for the rest of the equipment.

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Is there not any over current and overload protection for motor contactors?

Well, the contactor that welded itself in the on position was a pretty simple mechanical contactor. There wasn’t really any protection built into the contactor, but it is a little surprising that the breaker didn’t trip when this happened on Douglas.

Breakers are there to protect the wiring in the wall, not the machines. I wouldn’t expect the breaker to trip for a stuck contacter.

Perhaps we need to look into machine specific over current protection. I can run some sizing calcs when I get to the space tomorrow. The machine can pull more than it can handle and still be under for the main breaker supplying it. Each branch circuit should have over current protection on it. When I was an engineer we used fuses because it was cheaper and easier to replace em. If a breaker blows once it looses its rating…making it easier for it to blow or weld together internally.

Just a few observations, ignore me if I misunderstood the situation….

Does the motor not have the typical thermal reset switch all of my air compressors have had? That is the final layer of protection, but it only saves the motor/wiring to the wall as the breaker saves the wiring in the wall. It more sounds like a timing function is what is being desired. That power is only active for x minutes it takes to fully fill the compressor tanks, but beyond that the timer flips and gives an error, warning, etc. This is something I have thought would be desirable for my own shop after finding compressors running non stop at max pressure dumping excess air out the safety valve… My issues have been the pressure switch failing to open and contactors failing to operate, but neither ruined my expensive compressors. As fare as circuit protective devices like fuses/breakers, they won’t prevent a contactor sticking in the on position or a pressure switch sticking in the closed position. I have considered a redundant approach with 2 pressure sensing and the second having the ability to disconnect power from the main contactor, but have not implemented this idea as I have only had 2 or 3 issues in 20+ years with many other pressing needs taking priority. Another idea I have not spent much time thinking about would be an occupancy sensor, that after x time of no movement in the room the electricity to the machine would be disconnected. Similar to occupancy sensors on lighting, if no one is there it turns off until someone enters, removing the necessity for someone to remember to turn the compressor off when done.

My understanding is that the load on the motor of a compressor is pretty high, and when running a 240v motor at a lower voltage (208), current must necessarily increase (Ohm’s Law and all that), which increases heating in the windings and shortens the life of the motor. It is particularly an issue with compressors because of the high starting load when the tank is pressurized.

I like the idea of an occupancy sensor. I have always relied on the pressure switch but I’m not religious about turning off the ball valve on my tank so I do sometimes worry that a hose could burst, which I’ve had happen before, and the compressor would just run continuously. Of course, in that case it’s under little load as the air is just bleeding off into the atmosphere. When the motor burned up, was it because it continues to run under the load of a full tank? And did the relief valve not open up? I know I’ve looked at it before but I don’t recall if the compressor has a separate contactor aside from the pressure switch or if it’s all an integral unit.

What about changing the motor to a 5hp 208 single phase? 308 for a baldor that will never die, or at least really hard to kill. They are what we use on the pizza ovens and they always break the gears before they burn out.

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