Waterproof CNC Router Cutting bed

[mondrota]

Hi all,
i'm new to the forum so excuse me if this post is in a wrong place.
So here is my problem:
I'm looking for a decent material to use for my DIY CNC router cutting bed (working area of 800x480mm). I need it to resist moisture as my router is in a garage that gets really damp during winter, and my current bed (plywood + mdf on top) expands and contracts like crazy.. I do a lot of V carving so a flat bed is a must.
So at the moment I'm considering 20mm thick acrylic or 20mm HDPE sheet. I'm looking to spend up to £100 if possible. The entire bed size is 1100x620mm.

So what do you guys think I should do? I just need a material that will resist moisture and bending.

CHeers, Kamil

[Maxakarudy]

There is a sign material called Foamex, I use a 19mm thick sheet, you can drill and cut it like MDF, but it's moisture resistant as it's plastic, it's nothing like perspex btw
Martin

[mondrota]

Thanks Maxakarudy,
Is it also a rigid material that won't deflect much while cutting?

[Clive S]

Thanks Maxakarudy,
Is it also a rigid material that won't deflect much while cutting?

You will need something that you can drill and tap into as well.

[Maxakarudy]

Yep,
I have an industrial router, that's what most sacrificial beds are made of

[mondrota]

Ok, so I have 3 options now. I checked this foamex on ebay and it is much cheaper. I can drill holes and glue in t nuts at the bottom. I'm just a bit concerned about the rigidity of this material. It is a light foam material after all..

[Maxakarudy]

19mm is very rigid, find a local sign company, they might have some to show you and could get you a sheet, Ebay is way too expensive

[bobby]

Ok, so I have 3 options now. I checked this foamex on ebay and it is much cheaper. I can drill holes and glue in t nuts at the bottom. I'm just a bit concerned about the rigidity of this material. It is a light foam material after all..

How about Rigid PVC BLACK PLATE/SHEET 1520mm x 1300mm X 25mm THICK

ebay item number: 152320149415

Machineable, tappable, solid!

A bit big for your purpose though? Maybe he would cut it??

[mondrota]

Thanks for all your input, I'll see how I get on and will keep you informed.

[Dean jeffery]

I've been looking for the trespa Athlon stuff, I was quoted £90 plus VAT for a bloody off cut 600x400.