In this video, I assemble a MDF worktop with a rotatable sacrificial insert for a floor standing Meddings pillar drill. This is designed to be CNC cut out of 18mm MDF, and used to increase the work area which support large woodworking pieces. It also provides more space to clamp material down, and to generally make drilling safer, comfortable and more precise.

00:00 Parts & Fixings

• 4@ M12x50mm Hex Bolts
• 4@ M12x40mm Washers
• 4@ M12 Nuts
• 1@ Sacrificial Insert
• 1@ Top Section
• 1@ Middle Section
• 1@ Bottom Section
• 5@ M5x50mm Wood Screws

01:05 CAD model in Fusion 360

I designed this back in 2018 in Fusion 360, and periodically machine them out when I need to replace parts on the drills I look after. This is a no thrills, simple version with no additional features.  Any jigs need can be mocked up specifically for the task or made as a separate attachment. There are thumb holes for lifting the disc out when necessary.

01:26 CNC CAM Software – Vcarve Pro

I nest the parts which auto arranged them to make the most economical use of the material. I will also cut out an additional disc insert to have as a spare. I will need roughly 760x1220mm of 18mm MDF for this cutting job. The scraps from this job will go into a recycling box to use for smaller projects. I tool up my inside cuts first – using tabs for the larger opening within the top section. I set a last pass thickness of 1mm to clear out MDF dust from the cut line and minimise the amount I might get exposed to when cleaning up the pieces. Other important things to pay attention to include the cut line being on the correct side of the vectors, inside in this case, and to select a conventional direction for the cutting path. After which I tooled up the outside toolpaths, with 2-4 tabs per piece of ensure the objects don’t move when being cut free from the larger MDF workpiece.

03:10 Toolpath Simulation

It can be a little boring watching a CNC montage, so I will not share that. But before any cut it is important to simulate the cut and try look for any anomalies. This can prevent you ruining a cutting job, wasting material, or damaging the CNC machine.

03:32 Assembly Process & Installation

I place the M12x50mm bolts into the metal sub-table slots and align the holes of the bottom MDF section. Ensuring the handle is clear of the MDF, I loosely hand tighten all four M12 nuts with their washers underneath. I then place the middle MDF section above the bottom, adjusting the washers slightly so the edge of both pieces become flush before clamping them in place and fully fastening using an impact driver.  The top section is now clamped into place and all three MDF section can be screwed together using 50mm wood screws.

05:52 The Good The Bad And The Technical

The clamps can be removed, sacrificial disc inserted, and now the drill is ready to use.