[hazelelectronic]

I am looking for advice over what sacrificial material I can use on my newly acquired CNC router. I am cutting out acrylic parts and have built a vacuum table to assist in holding the material flat but I need a sacrificial material to protect the vacuum table and cutter whilst at the same time allowing air through in order to pull a vacuum against the underside of the work piece. I will cutting out various size parts from 5 - 8mm acrylic sheets 1200 x 1200.

All help and ideas gratefully received.

[bill south]

The material you want is LDF (Low Density Fiberboard) which is a lighter version of MDF! It goes by another name but I'm getting old and CRS has set in. Maybe someone will chime in and help. The big box stores most likely will not have it but the internet is your friend.
Good Luck.
Bill

[ger21]

How big is your pump? You can use regular MDF with a 10HP pump or bigger.

[hazelelectronic]

Hi Bill
Thank you for your help. I wasn't familiar with the term LDF although it did stir a few of the remaining grey cells. On consulting the internet of images I can see it is what is commonly referred to over this side of the pond as 'chipboard'. Here is the thing though and please excuse my ignorance but Chipboard is full of glue so doesn't that prevent the air getting through it? I guess the thinner it is the more likely that it will work but I don't think I have ever seen chipboard here thinner than 1/2". Looks like I will be bashing the nearest proper wood yard to see what they can come up with.
Thanks again.
Ray

[hazelelectronic]

Hi Gerry. I am using an 850w 'Henry' style hoover. Don't know what that equates in horsepower but I am guessing it can't be much.

So is MDF really porous?
How thick is the piece you use?
Do you have to machine off the smooth surface to make it so?

Having a little trouble getting my head around air passing through that heavily compressed smooth surface.

many thanks
Ray