[JPMach]

What is the best way to build a water trap for a vacuum chuck workholding system. I tried running my vac chuck today, and there must have been an small leak, with the coolant on the vac pump soon starting spitting out oil as there was to much water coming through. (nuts)
After a change of oil I got the part done by turning the coolant off, but not as good of quality cut. I saw one site on the internet that sells a automatic coolant return system, but they don't say anything about how it works. Does anyone out there have one of these or something similar and can tell me where to buy one or how to build one?

Thanks
JP

[Scott_bob]

JPmach,

we have vacuum systems on all our CNC machines with this type of trap:
http://www.coleparmer.com/catalog/pr...sp?sku=7970070



These are available down at the local Home Depot... (For a lot less)
A nice good capacity bottle is best for collecting any coolant that gets by your seal.

[Geof]

JP;

Have you tried just taking an air tank and putting it between the vacuum chuck and pump? Provided you separated the inlet and outlet plumbing this would catch most of the coolant as well as give you a vacuum reservoir to give a good fast initial pull down.

[JPMach]

Actually I made up a automatic water trap a while ago with about a gallon or more capacity. I will have to take a pic of it later and post it here. I am quite proud of it. It consits of a length of 4" pvc 24" long with a 4" to 2" reducer on top. The 2 " cmes down inside of the 4" a couple of inches. The main Vaccuum line is attached at to the 4" in the reducer fitting, amd the line from the clamps is in the top of the 2" thus the airflow is forced to go out pass the end of the 2" and make a 180 deg turn. At the bootom I attached aothe line tha runs to the coolant tank. in this line I put a check valve. When the vac is on the valve is closed, as soon as the vac is off the coolant returns to tank!
It works very well as I can suck up straight coolant without any every getting to the vac pump. I also put a sight tube on the side of my contraption so that I can monitor how full it is for long runs.

JP

[Geof]

Make a bigger one!

I am in the early stages of setting up a vacuum table on a Haas gantry router and I decided to go the route of using compressed air venturi vacuum pumps so I did not have to worry about sucking coolant into the vacuum pump. Fortunately I was able to get a used 60cfm rotary screw compressor to run the venturi for only $1000. If the specs for the venturi are correct the compressor should run enough of them to give me about 50cfm of vacuum flow at about 10 to 12 psi negative.

[JPMach]

Here is a pic of the trap I made. It is attached to the side of my mill.

[One of Many]

JP,

Could you post a cross sectional view of this trap?

What was the check valve you used in the drain?

The ones I see on the web use a 5 micron filter. About the same configuration as I understand your construction.

I have a couple systems that continuously get water in the oil.

Thanks,

DC

[JPMach]

here is a cross section. Sorry, it's the best I could do with out spending to much time on it. The check valve I got from surpluscenter. It is just a cheap one. It has a plastic plug in it that is retained by a dowel pin through the side of the housing. Whole thing is only about 1.5" long. There is no filter in my trap, I suppose ther should be but I was only worried about water leaking past the seals on my clamps. I used all push to connect fittings as it is easy to change around.
You have to look at the specs on the push to connect stuff to get the right stuff that can handle vac. I use a vac made for refrigeration so not much volume but alomst 30" hg.
I have had the entire system up to the max vac pressure and everything holds together good. Made a manifold out of a block of aluminum with 6 ptc fittings in the side and one on the end. It also bolts down to the table in my mill so it stays put.
With the sight tube on the side you can monitor how full it is getting on long runs. It is a bit hard to see as any coolant that is inside is boiling feverishly.

JP

[One of Many]

That is as I had interpreted it form your picture. Nice job, this really adds clarity to the unit!

Thank you kindly! I'll build one for what it is worth. Better than the commercial price, that is for sure.

DC