Let's Make Robots!

How to cut Plexiglas (Acrylic sheets)

Plexiglass / acrylic plastic sheets is a great material when building robots.

If you are having electronics and mecanics on each side of something, and want to pack cables, motors, sensors etc in a tight space, it is great to be able to look through your "base".

It is so much easier just to look where to drill than measuring etc.

Double-adhesive tape glues extremely well to this, and it is nice plane etc..

BUT! It is impossible to cut.

You should think it is easy, but it is not.

Either you crack it, or the wierdest thing happen; Just behind your blade, it melts back together.

I did not believe this was a problem untill I saw it with my own eyes.

If you look at the web (as this was not) - you find thousands of strange advice; Put spirit on the blade, go slowly, go fast, use fine tooth, use rough blades.. And I have tried it all and was about to give up.. untill i found this:

There are special blades for jig saws, made to cut acryllic. And they WORK! That´s it! :)


Transparency can be a bliss :)

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TIP:  To get the cut edges of plexi back to transparent, take a razor blade and scrape the edges with the razor blade perpendicular to the plexi to get loose pieces off and clean up the edge.  Then pass a propane torch quickly over the cut edge.  It does not take long at all and does not require a lot of heat, just run the heat from the flame over the cut portion.  The flame does not need to actually touch the plexi.   It takes some practice, but turns crystal clear and looks great when you get it right!

Where can I Find Plexiglass / acrylic plastic?
hardware stores

you can fet them from lows or home depo or eplastics.com

whenever i've cut plexiglass i've use a tool to score a line into it and then I just put it on the edge of a table and crack it.  it works really well.  you can really only get stright lines using this method but i've never had a need for a curved edge.  I've never tried using any sort of saw on it because i figured it would just crack. 

I have found that spit (yes that stuff in your mouth) is probably the best cutting fluid you can use to get a clean cut.

Just about any liquid works well provided you keep the cutting area wet.

If you are drilling acrylic and wabt a crystal clear hole, spit on it keeping the bit wet all the way through.

I learnd this early on as a machinist.

It sure is an unorthodox method that reveals great results.

Obviously when cutting large amounts you face dehydration.

For edges I use a wood plane with the blade set for a very shallow depth of cut. Shallow depth prevents the blade from stopping in mid cut allowing for a long smooth clean finish, and yes you got it spitting on it makes it easier to cut and prevents galling and burning.

I also sometimes warm acrylic in hot water or in an oven set at around 150deg C to soften it then cut with a scissors. This method works best on the thin stuff and allows you to cut clean radii etc.

Are they straight, or wavy? i got some, that supposedly are for acrylic, though i'm not sure if they are supposed to be wavy :S


thanks :-)

Hang on, I will go over and check :)

Mine are absolutely non-curly, but straight out flat as I !


hmm, guess i'll be returning them tomorrow, maybe i should try on some scrap piece of plexiglas first, who knows...


thanks again :)