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DIY Vacuum Table

Vacuum table made out of aluminium with some features

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In this project, we'll create a "cheap" vacuum table to hold our workpieces, especially, flat material. The table should be at least suitable for milling aluminium and maybe, steel. We will add tons of features to the vacuum table as seen in commercial alternatives.

The files to recreate your own version of the vacuum table will be published here as soon as the project is finished and the table is working. When creating your own version of the table, the size of the table can be variied. I'll explain the details of the design while the project is running.

For my CNC router, I'm in need of a method to hold my workpieces. Sticky tape does work, but it is a pain to remove it after milling. Furthermore, the presented method of NYC CNC using superglue also does work very well, but it requires lots of preparations, namely, very clean surfaces, tape has to be applied accurately to both, the workpiece and the mounting plate, glue has to be applied to the workpiece, accelerator has to be applied to the mounting plate and finally, after all that preparation, it is important to align the workpiece quickly before the glue fixes the workpiece in place.

Thus, a vacuum table is a very smart choice to fix workpieces quickly and safely to the mounting plate. There are different choices for vacuum tables, but I decided for a "breadboard" style table, since it is quicker to use. Sebastian End of END CNC has shown the easy use of a breadboard style vacuum table.

The CAD design is already close to finish while starting this project on Hackaday. We decided for a size of 450mm x 300mm, because 300mm is close to the limit of our CNC machine in one direction. The limit of the other direction is chosen like this, because we wanted to have free space beside the vacuum table, e.g. for a vice. Furthermore, we the following specs and features we would like to have in our vacuum table:

  • 450mm x 300mm x 31.5mm dimensions (height resulting of the available aluminium)
  • 10mm distance from hole to hole, so that many commercial rubber mattes will fit (e.g., the matte shown in the video of END CNC)
  • 5mm diameter of the holes, but just 0.2mm to supply the vacuum to the parts
  • Holes with M6 threads to clamp stuff onto the vacuum table
  • Three vacuum chambers
  • Possibilities to add end stops to three of the four sides
  • About 4 mm additional thickness to be used to plan the surface if required 

The current CAD model consists of two main aluminum parts, some sealing mass, pneumatic connectors and some screws. That's it. 

To use the table, some other parts are required. At least one vacuum pump, some tubes, mattes with 5mm holes (10 x 10 raster) and some mattes to close the remaining holes of the table.

There is a video series on Youtube where the parts are machined and assembled. The videos are linked below.

Hackaday Vacuum Table.stp

Current version of the CAD model

stp - 7.38 MB - 07/03/2019 at 19:24

Download

  • 1 × Sheet of aluminium for base plate 460mm x 310mm (at least 20mm thick)
  • 1 × Sheet of aluminium for top plate 460mm x 310mm (at least 20mm thick)
  • 3 × G 1/8" to 12mm pneumatic connectors Teflon tape should be used, 12mm can be exchanged to your needs
  • 20 × M5 x 12mm screw DIN 6912 Low Head Socket Cap Screw Grade 8.8
  • 1 × Sealing mass

  • Machining of top plate

    oMtQB42 days ago 0 comments

    Before milling the top plate, I tested the 0.214mm drills on some aluminium parts and there has been no problem to drill about 3mm deep, i.e., 15xD. But when it comes to drilling in the actual top plate, I couldn't get it to work. More on that later in this log entry.

    As shown in the video below, the first cuts on the aluminium for the top plate have been done. The outer contour, the 5mm holes and the counterbores have been milled and drilled successfully.

    If you have any questions on the milling or drilling, just ask in the comments here or on Youtube.

    Now, to the problem with the 0.214mm drills. Although drilling the small holes worked on a test part, I had huge problems to just drill one single hole in the actual top plate. There are several possibilities, why it didn't work.

    • Runout of the drill: it seems that the drills are not straight when testing them on a very accurate surface plate. I really think that is one of the main reasons why it didn't work. Maybe, for the test cuts the drill just was good enough. The runout measured is about +/-0.05mm, which is at total about half the drill size. (I really assume, that this is the problem)
    • Speeds and feeds: more rpm required or other feeds, I tried at 18000rpm and 50mm/min. These parameters worked for the test cuts.
    • Stick out: since the holes in the top plate start at about 8mm depth, the stick out of the drill has to be about 10mm. It may be a few mm longer than before when drilling in the test material.
    • Other material: the material of the top plate differs from the materials of the test cut.

    What I can definitely exclude from the reasons of failure:

    • Spindle runout: the runout is <0.01mm, so it is very unlikely that this is the problem.
    • Stability of the mill.
    • Programming errors: the drill isn't moved quickly into the material or something.

  • Material arrived, test cuts

    oMtQB44 days ago 0 comments

    Last week the material arrived. A few days ago, I sawed the aluminium sheets into correct pieces. Every piece is about 10mm larger in x and y.

    As said before, the main problem will be the 0.2mm holes that should be created. Thus, I ordered 10 drills with 0.214mm diameter a few weeks ago with 1mm shafts. I used one to do some test cuts, i.e., drilling 3 holes each 3mm deep (15xD). And surprisingly, it just worked. The holes had been drilled by the mill without a problem.

    Ok, so with the successful test cuts, I prepared the sacrifice plate.

  • CAD model uploaded

    oMtQB407/03/2019 at 19:23 0 comments

    We've uploaded the current version of the CAD model. Some minor changes have been applied compared to the project images. At the current state, the table could be milled and assembled.

    If you see some problems in the CAD model, please do not hesitate to write a comment.

  • Material is ordered, last changes of the CAD model

    oMtQB407/03/2019 at 18:32 0 comments

    Material is ordered. To make it simple milling the vacuum table while providing perfect surfaces at the top and bottom of each part, pre-milled aluminium has been ordered. And to make it a cheap vacuum table, we ordered remainders. The plates are much larger than required. On the one hand we have to cut them into pieces. On the other hand some material can be used for other projects. Just for your information, the remainders are more then double the material we need, but at about half the price.

    Furthermore, we ordered some tools (0.2mm drills), the pneumatic connectors and the sealing mass.

View all 4 project logs

  • 1
    Milling of top plate

    When milling the top plate, it is important that some things of the plate are not milled in this step. So, here is a list of things you should mill in this step:

    • Border of the plate, so that you get the correct dimensions.
    • Holes for the dowel pins (holes through the plate, 6mm with tolerance m6). Since you will use a milling machine or router, try to create the holes a little bit smaller and than converge to the correct tolerance.
    • Sunk holes for M5 screws
    • First type of vacuum holes (5mm)
    • Second type of vacuum holes (0.2mm)
    • Outer thread holes (just the holes with threads at the edge of the top plate, but not the threaded holes between the vacuum holes)

    For the vacuum holes please take note of the depths and the angle of the 5mm drill. At the end, just the 0.2mm drill should drill through the plate.

    Here is a list of things you should not mill in this step:

    • Threaded holes in between the vacuum holes. They are milled after the table has been assembled and go through the top plate into the bottom plate

    Below a picture is shown of the top plate. The required things to mill are marked.

    Milling steps of top plate

    See part 1 of the machining and assembling series on Youtube: https://www.youtube.com/watch?v=dRxbjm6g7WI

  • 2
    Milling of the bottom plate

    When milling the bottom plate, it is important that some things of the plate are not milled in this step. So, here is a list of things you should mill in this step:

    • Border of the plate, so that you get the correct dimensions.
    • Outer pockets to get places to mount your vacuum plate to the work table.
    • Holes for the dowel pins (6mm with tolerance m6). The holes should be so deep that the dowel pins stick out about 4mm, depending on the dowel pins you have available. Since you will use a milling machine or router, try to create the holes a little bit smaller and than converge to the correct tolerance.
    • Holes with M5 threads

    For the vacuum holes please take note of the depths and the angle of the 5mm drill. At the end, just the 0.2mm drill should drill through the plate.

    Here is a list of things you should not mill in this step:

    • M6 holes with threads. They are located on top of the "crosses", except 4 holes. They are milled after the table has been assembled and go through the top plate into the bottom plate

    Below a picture is shown of the top plate. The required things to mill are marked.

  • 3
    Drill holes at sides of bottom plate

    Since the dimensions are not suitable for a normal CNC router, the holes at the side has to be drilled manually. 

    At one side you have to drill the correct holes for a G 1/8" thread, i.e., 8.8mm. 

    At the other three sides holes for M5 threads have to be drilled (4.2mm).

View all 9 instructions

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