HomeCNC, You ask a good question. The pads lugs are perfectly aligned with the bottom of the pad itself. The pad seems to be uniform all around. If there was some variance then I guess you could turn the pad upside down on your router and mill a fraction of the bottom to make it perfect.
When the work piece is sucked down, the rubber allows the workpiece to come in contact with the hard plastic and islands. There is no warpage.
Moondog, It is made out of a very durable plastic. I doubt it would suffer from repaeted use. I guess the rubber may need replacing from time to time.
I would expect most domestic compressors to be able to drive 4-6 of these units quite easily.
You asked for Australian suppliers, the product is actually Australian made.(Hence my willingness to do the review) Go to
www.vac-clamp.com to find their retailers. They also export them world wide.
CNCadmin (Paul), You asked about noise. It is surprisingly quite ( Not counting the compressor ) Lets put it this way, once you turned on your router, you wouldnt hear any air noise at all.
I dont know why you would want to put a vacuum onto this device in the first place. It does a fabulous job on its own with the compressed air. I tested the slippage up to 100 kg and it only just started to move, I doubt there is any cheap vacuum systems that could do the same. I was tempted to do a pull off test, but was afraid the tabs might break off with the possible 200 kg force required.
One other thing I failed to mention in the review was the fact that the rubber seal can be re-routed to form a smaller square or shape. This makes it suitable for small projects too.