I’m loving this new theme of build threads, and i was inspired by user Lavarat to come up with my own. I’ve been following the aging hipster build for a little while now, and it finally pushed me over the edge. I wanted to make a vacuum setup.
As always with me, it’s on the cheap! Practically free! FREE!!
So to begin, a little something to know about vacuum setups. Lots and lots of people use a repurposed Freon pump. However, a proper vacuum pump can be had for about 100$ new, even better models can be had even cheaper on eBay and craigslist. I am a project junkie, i love to tinker; and im always tight on cash. This is a very effective and cheap way to do this and it was a lot of fun to make. I encourage anybody who wants to do this however, to read up on circuitry, currents, and general electrical work if you are uncomfortable working with electrical parts.
Types of Freon compressors-
Scroll, Piston, Vein, and Diaphragm. I have been told scroll is the best. I have made a piston type in the past and it seemed to work just as well though. They are all very even. The scroll and vein will be SLIGHTLY louder. A whisper louder in my case.
Where to get your compressor-
You can get yours in any appliance that uses phase changes, or Freon. Things like air conditioners, Fridges, Mini Fridges, humidifiers, Dehumidifiers etc.
I had been hunting around for a discarded fridge or AC unit, but no dice. So i went to my neighbor’s house and asked if they had anything that was broken or not used anymore. Luck would have it they did! A medium sized dehumidifier they bought a long time ago that hadn’t worked in years. I felt around the copper lines in back and nothing was cold, i also found a small crack in the rear of the condenser where the Freon had drained out. I took it all apart and cut the copper lines outside on my lawn. A tiny amount of Freon was still left inside. After the pump was liberated from the casing i removed the main PCB, capacitor, and all the left over wiring which i got to use later when i made my wiring harness.
I drove to Lowes and picked up a coil of 1/4ID vinyl tubing (5$) 2x 1/4 barb fittings (5$) a junction box and a few screw in connectors to tighten all the wires in (1$) and some thread sealing tape and putty (5$) A grand total of 16$ for a vacuum pump. Not too shabby.
I mounted the compressor and the junction box on a small piece of wood with the rubber feet that were in the original unit. I copied down a wiring chart for the pump on an old pizza box and did my wiring according to that. It’s a three phase pump, add takes a starting current to get the motor running. The leads to the head of the pump were labeled, C, R, S, for common, run, and start. The common in the three prong cable was tied to the common on the pump, the hot was tied to an old toggle switch i had then to one side of the capacitor. From the same side I tied the hot cable to the “run” lead on the pump. With the last lead on the pump, the “start” lead, i ran that to the opposing side of the capacitor. I then grounded the whole thing to the body of the pump. After buttoning up all the wiring and stuffing it all into the junction box, it was good to test. The pump cycles from its starting cycle to its run cycle automatically with a flip of the toggle.
I took my tubing and pushed it onto the suction side of the pump and used a small hose clamp to secure it. The pump had little to no oil in it, so i dipped the suction end of the pump into some compressor oil and let the pump suck in a little oil.
It runs hot naturally, as there is no Freon in the loop to cool the pump. I don’t run it for long periods of time. It’s used to draw a vacuum, then the bag is sealed off and the part of left to cure. No continuous run.
- If you have a single phase pump, you will not have nearly as many steps. Just follow the wiring diagram on the pump directly to the wall. Always include capacitors and resistors in the circuitry around the pump.
- If your leads on your pump are not marked, use a resistance gauge to test them. The lowest resistance will be your common and run. The Middle resistance will be your common and start, and your last and highest resistance will be the Run and Start. Draw a little diagram with the wire colors labeled, and find the common wire. Tie that wire in and wire around it to finish the pumps wiring.
- BE SAFE!!!!!! I made a mistake before on the first pump i made, and it was disastrous. A huge arc of electricity went from the harness to the body of the pump. Always ground you and your work. Never ever work with anything plugged in. Always cover open connections.
- To cover difficult areas, use plasti-dip. Stuffs rad. I dipped my whole capacitor in the stuff with the wires attached as well as the bottom of my switch. Watertight and safe to touch even when current is running through them.
In my next post I hope to cover more of the plumbing and making the vacuum bag.
Thanks for reading