MDF used as vacuum table

[woodman-46]

Hi , I am in the process of buying an engraving machine and a milling machine from Roland. I have seen both working and am very impressed by their versatility. I gather that I can buy a vacuum table to hold pieces as an accessory for both machines but they seem pretty expensive.
I have found out from the salesman that one can use MDF as a vacuum table with a vacuum pump as the "suction" source. It is highly porous and obviously nice and flat, ideal. What I am not sure about is how one gets the vacuum through the board. Do I fit a shallow box underneath to be able to fix the pump nozzle into and presumably if I want to hold only in one smallish area, which I do, I mask off the area that is not being used. I guess that the edges of the board/table have to be sealed as well. Has anyone experience with this and if so how did you go about it.

Thanks in advance
James

 

[Pete W]

I find it difficult to believe you could suck anything through a sheet of MDF.

On the other hand, it is nice and flat and stable so it would make a good top for a vacuum table with a number of suitably sized and spaced holes drilled through it.

In fact, I'm pretty sure there was a project in New Woodworking in the last couple of months that gave step-by-step instructions for making a vacuum table for sanding, etc. Unfortunately I no longer have the issue, but someone else might. You could probably get a copy from the publishers.

 

[Chris Knight]

James,

I have seen it done with thinnish MDF (probably 6mm) at a woodworking show. Whether or not that would be a strong enough base for your purposes, I don't know.

I guess a grid of small holes might work too but you would have mask off the area not in use as most vacuum generators/pumps could not keep up with the leage of unmasked holes taking air in.

Sites like this one may help, although this is primarily about veneering with vacum https://www.qualityvak.com/index2.html

 

[CYC]

James, have you got a link to the milling machine you refer to?

 

[woodman-46]

Hi CYC, Your best bet is to just type in patrick thorn and co into your search box. At the bottom right of the page is a heading mdx-20 milling machine and click on that. This is one of the two smaller machines that roland do. They probably have info of the larger two there as well, these are pretty heavy duty but benchtop. I went to Slough and saw the machine working(it is also a scanner and was really impressed with its dexterity Patrick Thorn is the agent for Roland in the London area and is a really nice guy.
I will experiment with the MDF idea and get back to other replies

Thanks James

 

[Midnight]

I'm guessing that a scaled-down "down draft table" is gonna be close to what you need.. the tricky bit's gonna be finding / making a suitable adaptor to connect to a hose. I'd be inclined to use an HVLP DC as it's better suited to running with the hose effectively blocked; it should be more forgiving on the ears too... Personally I'd prefer to use something like 6mm birch ply rather than MDF, but that's just because I'm fussy...