Experience with a Robinair Vacuum Pump

Re: It should work *LINK*

Dave Paine

I do not have direct experience. My local turning friend has another brand of rotary vane oil bath vacuum pump, a CPS model.

A recent thread on vacuum pumps has a lot of information.

The Robinair looks like my friends CPS model. A rotary van with oil bath design. I think designed to pull a vacuum on air conditioner piping prior to adding the refrigerant. Hence they are designed to generate very high vacuums. Higher than needed for turning.

I looked at the manual. It states to replace the oil after each use. Wow, not practical for turning.

I would purchase oil rated for vacuum pumps. You may need to get this from MSCDirect, Grainger, etc. Just do a search for vacuum pump oil.

The high CFM will be designed for faster piping / equipment evacuation. Also good for turning. Many variables to cause leaks in turning, the fit between the wood and the chuck, the porosity of the wood. Higher CFM is good to maintain vacuum with such leaks.

I have a Gast pump which is lubricated rotary vane but not oil bath. Mine is about 2-3 CFM and generates up to 27+in Hg vacuum. This works well for my needs.

My friend found that the oil bath rotary vane design creates a fine oil mist when he operates the pump. It did not take long for a cloud of fine oil mist to fill his basement shop.

He had to come up with an absorber for the oil mist. He took a page out of the piping designer books in the company we used to work for. Oil lubrication systems for large compressors also generate oil mist. The designers create "K" filters to absorb the oil mist. For a long time I used this term but did not know the "K" stood for Kotex, as in tampons. Makes for a good absorbing filter for many fluids. LOL

My friend has a piece of PVC pipe filled with "K" filters attached to the vent at the top of the pump. It works well. No more fine oil mist. I do not know how often he needs to replace, but not expensive.


http://www.woodcentral.com/woodworking/forum/turning.pl/page/1/md/read/id/497696/sbj/vacuum-pump-availability/

Re: It should work

David Walser

I looked at the manual. It states to replace the oil after each use. Wow, not practical for turning.

I believe the recommendation to replace the oil between uses is that the oil will become contaminated with the air conditioning refrigerant being sucked out of the HVAC unit. I don't think that would apply to our use.

Re: It should work

Robert Edington

I saw that too. I wasn't going to do it. Just keep it full. I should get it Friday. Turning my rotary adapter tomorrow.

RP