Need help identifying this compressor

by Kevin
(Virginia Beach, VA, USA)

Mills Novelty Company compressor?

Mills Novelty Company compressor?

Mills Novelty Company compressor?
Mills Novelty Company compressor label
Identity of this older compressor
Twin cylinder compressor pump

This compressor is in my grandfather's garage. He passed away 2 year ago and his work shed is mostly untouched.


My family would like to see his tools go to good use and this compressor caught my eye.

The wheel still turns, but I'm cautious about turning it on until the oil has been replaced (at the very least). The tag on the frame indicates:

Mills Novelty Company
Model 42
Volts 220
Cycles 60
Serial 1766
Amps 6.4
Phase 1
? 15 lbs
CH-CL
the rest is illegible

Are there any serviceable parts for this compressor?

How can I tell if this is worth rebuilding?

Thanks for any information!

Comments for Need help identifying this compressor

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Mar 26, 2017
Tach
by: Doug in s.d.ca.

See my unintentionally anonymous post on the 21st.

Being a brush type motor, it will likely run at progressively slower speed until cut-off.

If it stops making air before cut-off, then it's either the pump going bad or there's a leak somewhere.

Mar 24, 2017
Low Pressure
by: Kevin

Good news! The replacement brushes for the motor work great!

But sadly, the compressor only pushes about 40 psi max. Is there any way I can tell the recommended RPM of the pump?

Mar 21, 2017
A little more info
by: Kevin

Looking at the tag a little closer, I can tell this was originally used as a refrigeration compressor. CH3CL (I thought the 3 was a - before).

Mar 21, 2017
Tach
by: Anonymous

What's the easiest (cheapest) way to check if the motor is running at 1175 RPM?

Define cheap...?

I was gonna suggest a DIY approach, but try googling "photo tachometer" - I was somewhat surprised, you may be too.

Mar 20, 2017
We Have Compression!
by: Kevin

I decided to bring it back to my house this weekend to drain the oil (that's an overstatement) and tear the heads down to check the reed valves. The sludge that came out was unreal. It looked like moisture buildup and oil breakdown, but fortunately no metal slivers or chunks. I replaced the oil with 3 quarts of 30 weight.

I pulled each head and there are two cylinders and valves per head. There are metal gaskets between the head and the valve plate and the valve plate and the cylinder. Those looked okay, so I saved for rebuilding. The valve plate had some surface rust, but came off with a wire wheel. I removed the valves. They are flat disks about 0.020" in thickness and are held shut with 4 small springs each. Once the air is compressed, it goes past the valve. The air moves past, then the springs push the valve closed. There's a little pitting in the edges of 1 valve, but the rest look ok for reuse.

I got everything cleaned up, put indian head gasket on both sides of each gasket, then reassembled the heads. I turned it on and I now have compression! Not much (about 20 lbs), but I think that may have to do with worn brushes on the motor.

I pulled the brushes on the Wagner motor and found that they are shaped like wedges and shunted together. I measured them and documented. I found the measurements to be (in inches) 0.13 X 0.21 X 0.74 X 0.68. (With 0.68 being the side that gets worn) I could not find brushes that were model specific, but I think I found some that will work from eurtonelectric.com.

I know I would probably have to replace the motor, especially if I wanted to push 220 V, but I figured this would be the cheapest way to start.

What's the easiest (cheapest) way to check if the motor is running at 1175 RPM?

Mar 14, 2017
New(er) motor
by: Doug in s.d.ca.

It will actually run at the right speed as long as it can get enough power to do so - but the available will be about 1/4 the rating. E.g. a 1HP rated 220v motor would only give about 1/4 HP.

We've seen a few cases where motors were run like that, and mostly they just blow a breaker at around 40 PSI or so.

Mar 14, 2017
New(er) motor
by: Anonymous

Doug,

There's only one intake and filter.

The replacement electric motor is 220V, 3.6 Amp, however, my grandfather had it wired for 110V. Surely, the motor is spinning slower and could cause it to overheat. He had it like that for years, I'm sure.

I guess my next step is to just pull the heads and inspect the valves, head, rings, and cylinder walls? I hope I don't break any bolts!

I just found the page discussing "make your own reed valves"

https://www.about-air-compressors.com/make-your-own-compressor-reed-valve.html

Thanks

Mar 13, 2017
New(er) motor
by: Doug in s.d.ca.

Well, the nameplate in your second pic clearly does say 220V, but it appears that motor was replaced - is there a readable plate on it? Could be 120...

Either way, I'd expect a little more from it.

That tee thing on the head looks like an intake filter and a broken second one - if that's the case, can air get into the head from there?

If so, then looks like it has finger valves, and they're probably shot. If that's all that's stopping it, you can make new ones.

Mar 13, 2017
RE: Need help identifying this compressor
by: Kevin

Thanks Doug. I turned the compressor motor manually and it spins freely, so I powered it up and let it run for about 3 minutes. None of the gauges went above the baseline reading. It runs (but I think the electric motor is incorrectly wired with 110V). I opened the drain valve to release any pressure and there was just a little bit of air coming out.


Mar 11, 2017
old compressor
by: Doug in s.d.ca.

Whether it's worth or even possible to rebuild it depends on what's wrong with it, if anything.

I'd say if it has oil in it and it turns OK manually, go ahead and power it up for a few minutes just to get an idea of how it's working, then go from there.

Piston rings would be most likely to be bad, and perhaps hard to find. Anything worse than that would likely be impossible to find.

Sorry, don't know what brand it is, but sometimes people drop by here and will help with that.

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