View Full Version : vacuum table & pump
07-24-2009, 08:53 AM
The vacuum table has been designed and off to be CNC cut. I asked our maitaince person if we had any vacuum pumps around and he said that there was one in one of our boiler rooms that have been there for at least 13 years. After talking to some people I found that this pump was owned by one of my co-worker that forgot he even had it. He told me – it’s yours – and off to the barn it went. He had it rebuilt 20 years ago and only used it once since then. I blew off about 2” of dust and plug it in it had suction. I ordered a vacuum gauge and inline filter on Ebay. Didn’t think it was a good idea to suck in Corian dust into this pump. Make: Kinney KS-15.
My goal is to design some shapes and CNC cut a bunch of items for sale. Here is the first test shape on the new table when it is complete.
I said I had a boat load of Corian – here is a picture of about 90% of it.
Anyone have any idea on this pump and if I need to know anything other than just plug it in and let it suck.
07-24-2009, 10:05 AM
Just something i noticed about that table youre designing, if your cutter just lightly touches it around the pieces you are trying to cut out, its going to wreck that suction ring and then you would not be able to use them for the next item.
07-24-2009, 10:19 AM
What are you going to plug the other holes with? If there is a leak anywhere, the part won't hold.
The vacuum tables I've used had a grid of squares. The seal was laid out in the grooves under the part. There was ONE vacuum hole in the center of the grid in the intersection of the seal gooves.
07-24-2009, 10:35 AM
At the center of each o-ring area there will be a SAE pipe plug (with o-ring). Only the full sections will be left to vacuum under the piece of corian. One thought is to only cut down to about .010-.015 of breaking through the corian since that can be just broke off once removed. I will be running a router around to put some type of corner radii on both sides. Only the o-rings will be installed that are fully under the part - all other o-rings will be left in the box.
07-24-2009, 10:47 AM
Be sure you remove 99.9% of the dust. 93% of the weigh of all acrylic solid surface material is ATH (aluminiun tri-hydrate) the remains of bauxite ore, after the extraction of the pure aluminium.
Very abrasive, gets into every nook and cranny, dries the heck out of your hands, bad for the lungs. So, exhaust or collect the dust from your shop.
07-24-2009, 10:53 AM
What you have is a very good brand of vacuum pump - Kinney. If you are able to prevent unused holes from leaking, it should work well for your vacuum table. Something you may face is distortion. For vacuum chucks and vacuum tables, it is important to remember in the design that you will be producing roughly 15psi force over the evacuated area. If you surface a part and then measure the flatness later, you may be able to see the chuck pattern. It will depend on part thickness and how close you look, but it is something to keep in mind.
07-24-2009, 10:56 AM
The pump needs to have the oil changed. The KS-15 was rated for about 15 CFM and 10 microns. (That is, 15 CFM at 1 atm and an ultimate pressure of 10 microns) It is doubtful whether you would ever get down to 10 microns, given the age of the pump and the setup. Either way that should be a good pump for what you want.
That is a single stage mechanical vacuum pump - a rotary piston type. The way it seals is by the addition of oil, there is no metal to metal contact like in an ordinary compressor. If this oil become contaminated (with moisture or anything) the oil will gas off at low pressure, preventing the pump from reaching a good vacuum. If it sits for more than a month, most manufacturers recommend replacing the oil.
You will need to replace it with a vacuum oil - not ordinary oils as these gas off at low pressures. According to the tech bulletin, you are looking for Kinney AX oil. I can email you the tech bulletin, if you would like. Just pm me with your address.
Kinney is now owned by Tuthill Corporation, but rebuild kits and etc are still available.
<edit> According to the manufacturer, "Gas ballast and large oil capacity enable them to handle moderate water or other vapor loads. KS and KD Models are air-cooled; KDH Models need cooling water for most applications."
Should be a perfect pump for your application.
07-24-2009, 12:34 PM
Vacuum systems do not like volume.
Do not use a resevoir, which is a common mistake folks make with such systems. small volumetric systems respond faster to pump capacity.
07-24-2009, 04:05 PM
With a vacuum table volume of air moved is your friend. This will take in account of any leaks. This is why roots blowers and regenerative blowers are used. We use a 20HP regenerative on out 4x8' table with a bypass set at about 10" water.
Use a piece of particle board 1/8" to 1/4" thick. The air will pull right through.
07-24-2009, 05:23 PM
Man your lucky that Corian is nice and the Pump too! Wow what a find , well done regards Alistair
07-24-2009, 05:24 PM
Bruce - Since I only plan to cut on the side of the sheet it shouldn't be a problem but if I plan to cut on the top, then maybe I need to add some shim stock under each area so I won't have as much surface area to distort.
Rich - I wasn't planning on a resevoir tank since if I get a leak the most is would do it launch the sheet. No big deal since I probably should be by it since I really want to hit go and let the machine run itself.
Fasttrack - thanks for the infomation.
07-25-2009, 12:05 AM
No problem! Like I said, if I find that manual, I will let you know. I think vacuum technology is fascinating, so I'm looking forward to seeing how you progress. I've never had to do anything "practical" with a vacuum, but I'm thinking maybe I'd like to experiment with a vacuum plate/table someday...