Instructions: Drilling PLEXIGLAS®
1
Do not remove masking film
Do not remove the masking film from the acrylic sheet.
2
Mark out the position of the drill hole
Mark out the position of the hole using a grease pen or permanent marker. The minimum distance from the edges is 1.5 times the required diameter of the borehole. Further information on marking out the drill hole position is available in the brochure Machining PLEXIGLAS®.
3
Clamp the sheet to the base
For accurate drilling, first, lightly secure the sheet with clamps or screw clamps to a firm, level base, of wood, for example; this could be a workbench or table. Before each drilling session clean the base so that no sharp-edged parts project from it. You may also clamp the material in a bench vice with protective jaws. Align the workpiece accurately before clamping it.
4
Set rotational speed
Many drills have the option to set the rotational speed. For neat results, working with a low rotational speed is recommended. As a rule of thumb: the greater the diameter of the borehole, the lower the rotational speed. Further information on cutting parameters is available in the diagram and the brochure Machining PLEXIGLAS®. You can also try out the appropriate settings on a practice piece (see also step 5).
5
Check rotational speed
The shavings produced while drilling indicate whether the rotational speed is correct. The images show the influence of rotational speed or cutting speed and feed rate on the quality of the drill hole, in this case with a PLEXIGLAS® sheet.
Above: optimal rotational speed and correct feed rate: smooth drill hole surface, smooth, continuous chip.
Center: rotational speed and/or feed rate too high: crumbly chip, rough drill hole.
Below: rotational speed and/or feed rate too low: overheating, drill hole shows signs of degradation, fused chip.
6
Align drill bit
Place the drill bit on the marking indicated and drill briefly. In this way you can check the position of the borehole.
7
Drilling
Switch on the drill before starting to drill.
Important: Shortly before drilling through the sheet, you should reduce the feed rate to prevent chipping.
8
Airing and cooling
For material thicknesses greater than 5 mm the drill bit should be regularly cooled down to prevent overheating. This is done by raising it briefly. You should also cool the drill hole. This is best done with water, which you fill into a wash bottle. Spray water into the hole at regular intervals. This is especially important for drill bits where shavings accumulate fast, such as when using spade drill bits.
9
Deburring the borehole
You should deburr the borehole on both sides, using a countersink; in this way the small notches arising during boring are prevented. For relatively large drill hole diameters you can use a scraper for deburring.
