Cutting Plexiglass with Dremel (Cutter & Method)

Dremel Multi-Tools are excellent for cutting and shaping smaller workpieces of different materials. This includes wood, metal, and Plexiglass, among other plastics.

This article investigates cutting Plexiglass using a Dremel and offers a how-to guide for this process.

Can You Cut Plexiglass With a Dremel?

Yes, you can cut Plexiglass with a Dremel rotary tool, provided that you use the correct blade and method. If you do this incorrectly, the Plexiglass material can get scratched or cracked, or it could even melt, ruining your workpiece.

Plexiglass or Polymethyl methacrylate (PMMA), also known as acrylic is a type of transparent thermoplastic. Cutting Plexiglass with Dremel is relatively easy to do when using a sharp blade suited to cutting plastics and following best practices.

The first step is to protect your workpiece from unwanted scratches and other damage. Plexiglass manufacturers provided an easy solution: the individual sheets are covered with thin plastic films or paper at the factory. These are meant to protect the sheets during transit, but they’re also great for protecting them while working on them. So, keep the film on for as long as possible.

While acrylic is a durable material, it is not unbreakable. For this reason, it is necessary to take various precautions during the cutting process to protect the workpiece from scratches, cracks, and other damage. To this end, it is best to stick to the recommended cutting bits and blades and use them at the recommended speed settings.

Exceeding the recommended speed setting could cause the blade to heat up, which could cause the Plexiglass to melt. This could potentially ruin the workpiece.

Cutting Plexiglass using a Dremel or other rotary tool creates plastic powder and tiny plastic shards. These can be pretty sharp, so protect your eyes by wearing safety glasses.

It’s also a good idea to wear gloves, although not everyone thinks this is strictly necessary.

Dremel Bit for Cutting Plexiglass or Acrylic Sheets

When you want to make straight plunge cuts in Plexiglass, the Dremel EZ476 (SpeedClick) is a great option. These plastic cutting wheels are designed to make clean cuts on acrylic and vinyl.

The Dremel 543, the 1¼” carbide coated cutting and shaping Wheel is excellent for making curved cuts in plastics.

Alternative cutting bits are available from other manufacturers that are compatible with the Dremel Multi-Tool. Some of these work as good as the original Dremel bits, while others don’t. Many people use them, though, since they tend to be less expensive.

You don’t want the thin abrasive discs to cut acrylic, because they can easily snap off. Should you decide to go for a third party bit, get one or two pieces and test first to ensure that they are adequately matched to the task at hand.

How to Cut Plexiglass With Dremel?

Photo by Rebeca Bolanos/Shutterstock.
Cutting Plexiglass with a Dremel Multi-Tool is relatively simple, regardless of whether you’re making a straight plunge cut or curved cut. Here’s a step-by-step guide to the process.

1. Mark the intended cut line using a permanent marker or sharpie. Leave the protective film in place to prevent unwanted cuts and marks on your workpiece.
2. Clamp the workpiece, placing a wooden board or another protective layer underneath. This will protect your work table from unwanted cuts and marks as you cut through the workpiece.
3. Select the correct cutting bit and install it in the Dremel Multi-Tool. I recommend the EZ476 plastic cutting disc.
4. If the workpiece is very thick, or if the cut is long, start a flow of cooling water over the cut line. This will keep the plastic from melting during the cutting process.
5. Connect the power cord and select the correct speed setting. Dremel recommends working between 10000 and 15000 RPM. Exceeding 15000 could cause the plastic to melt, so don’t exceed that limit. Instead, start at a low speed, increasing the speed setting as you work.

   Personally, I keep it even lower to avoid overheating. I usually start at 3000 RPM and start cutting along the sharpie marking. Once I have sufficiently deep notch along the cutline, I will increase the speed to 4000 to 5000 RPM.

6. Switch on the Dremel and gently place the cutting bit on the intended cut line.
7. Gently score the cutline: Move the cutting bit along the cutline in gentle, even movements, taking care not to apply pressure to the workpiece.
8. Once the entire cutline is scored, gently pass the cutting bit along the cutline in smooth, even movements until the cut stretches halfway through the intended cutting depth.
9. Here, you have two options:
• Switch off the Dremel and carefully snap off the workpiece along the cutline.
• Continue passing the cutting bit along the cutline, cutting all the way through the workpiece.
10. Switch off the Dremel and the cooling water.
11. Remove the protective film surrounding the cutline.
12. Gently wet-sand the cutline to remove burrs. Start with 120- or 180-grit waterproof sandpaper wrapped around a wooden or rubber sanding blog. Successively transition to finer grit sandpaper as the Plexiglass becomes smoother. Next, use a 369-grit sandpaper and finally, sand the cut using 600-grit sandpaper.
    Manual wet-sanding is typically more effective for this application than a handheld power sander, such as the Dremel Multi-Tool.
13. Buff the acrylic sheet using a buffing pad attached to an electric drill or Dremel Multi-Tool. Apply a polishing compound formulated for acrylic plastic to aid in this.

How to Avoid Breaking Plexiglass While Cutting

Plexiglass can break or crack easily during the cutting operation, even though it is a durable plastic. Here are some tips to avoid unwanted scratches and other damage to your workpiece during cutting:

• Don’t remove the film. Plexiglass manufacturers typically stick a thin film on both sides of sheets. This is meant to protect it from scratches during transport but can provide added protection while you work on it. You prevent scratches from your worktable and tools by leaving the film on.
• Use the correct blade or cutting bit. Match the blade to the application. A metal cutting disc will work on acrylic, but it tends generate more heat to binds faster.
• Ensure that the cutting disc is sharp. Dull blades cause unnecessary friction during the cutting process, potentially causing the Plexiglass to crack, break, or even melt. Dull blades also create a very rough cutline, prolonging the sanding process and making it unnecessarily tedious.
• Cool the blade. This is especially important when cutting thick sheets. During cutting operations, the blade heats up due to friction between it and the workpiece. When this heat build-up is left unchecked, it could cause the plastic to melt.
• If the blade is heating up, stop the cutting process and allow the blade and workpiece to cool. Adding cooling water when cutting through thick Plexiglass sheets is an excellent way to keep the workpiece and cutting bit cool.

Final Thoughts

A rotary tool is a versatile power tool that can easily cut and shape Plexiglass and is probably the only tool you will need for your acrylic projects.
But, what if you don’t own a power tool?
The score and snap method using a utility knife works well for thin sheets and for thicker material, use a hacksaw.