Vacuum tables are commonly used in CNC machining as an effective way to hold material onto the work surface while the rotary attachment cuts. We made a DIY version for one of our laser cutters to hold flexible and warped material flat while it undergoes laser cutting. The vacuum table allows full access to the surface, there is nothing to get in the way of the laser beam while it is cutting.
The vacuum table works by drawing a vacuum under the work piece, a series of holes in the surface of the table pull the material down onto the surface. The suction in this system is provided by a common household vacuum cleaner.
The laser will mark the surface of the vacuum table when it cuts all the way through the material so that should be considered as a sacrificial layer. As each part of this design is laser cut from cheap mdf a new surface can be cut when it has significant degradation.
Step 1: How to Use the Vacuum Table
Connect the hoover hose to the underside of the table and turn the hoover on. There will be some suction on the work piece but significant amounts of air will be drawn through the other holes. To maximise the amount of grip on the material you need to cover all of the holes in the vacuum table, this can be done with something as simple as a sheet of paper.
Step 2: How to Build the Vacuum Table
The table is a simple box design, the top surface has 2mm holes cut all the way across it at regular intervals. The table was cut from 3mm mdf.
There are a series of braces across the middle of the table, these prevent the top surface from being deformed as a vacuum is pulled through the box.
The hoover nozzle connects in to the table by a series of stacked disks. The hoover hose wedges into the hole from underneath and the whole table pokes out the front of the laser.
We have provided the files in the original svg and a dxf format. These were created in inkscape so if you have any problems opening them try downloading inkscape and exporting them in a format your laser does understand.
A second layer should be placed on top of the vacuum table. This would become the sacrificial layer and it would be more easily replaced than the current layer. It could be keyed into the lower layer using tabs to ensure that the holes in both layers are aligned.
A series of flexible hoses long the front edge of the table would be a better way to provide vacuum to the table. The hoover hose wouldn't be fixed underneath the table and the table would not have to poke out the front of the cutter. Hoses could be clamped on sections that don't require vacuum.
The vacuum table could be made as large as the cutting area of the laser.