Precision Plasticard Cutting Made Easy

After writing last weeks post I realized that cutting those shapes may be a bit of a PITA.  So I thought I should show you all something I learned when robotics was my hobby.  I used to use the following technique on sheet metal with great success.

For this post I did a simple design of an antenna in eMachineshop CAD software as seen in the last post on Rhino Extra Armor.



Once you have a design laid out on paper, in this case a simple antenna, cutting it with any sort of precision can be problematic.  But if you use this technique, cutting out your plasticard designs doesn’t have to be hard at all.  You’ll need…

• Your design printed with a water resistant ink/toner on standard printer paper.
• Enough Plasticard sheet to handle your design
• A glue stick
• Cutting implements: Xacto knife, scissors, paper cutter, etc.
• A container of water large enough to completely submerge your largest finished piece of plasticard.

Start with your design laid out as compactly as possible on the paper but leave room around the pieces (0.250” maybe) in case you make a cutting mistake.  If you share borders between multiple pieces and you make a cut on one piece wide, you’ve also just cut the adjacent piece short.  LEAVE ROOM!



Next, cut the paper down to a size that is more manageable.



From here you’ll cut out the individual paper pieces.



Once the individual paper pieces are cut, glue stick them to the plasticard.  You’re basically making a sticker here, so be thorough and try to cover the entire back surface of the paper.  Pay particular attention to the edges because if they don’t stick completely flat, it will make cutting them more difficult.

If your plasticard has straight edges, it’s perfectly fine to use them as an edge for the final part just like I did in the photo above.  Place the sticker and smooth it down.  Make sure there are no bubbles or raised edges.

Let the glue dry before you make any cuts or you may tear the paper while trying to cut it.



The plasticard with the paper stickers above are nearly ready for the final step.  I just need to clean up the edges some, maybe.



This step is the the coolest because it’s so simple.  Just drop the parts in water to soften the glue back up.



Let them soak for 10 minutes and the paper just slides off!



Slide the paper off, swish the parts in the water again, and then dry them.  Now you have very precisely cut geometrically complex parts!



In figuring out how far I could bend the pieces, I accidentally cracked one of the vertical bends and all of the mounting tabs on the stand section.  Turns out that plasticard doesn’t bend as well as sheet metal.

This forced me to add some reinforcement.  Looks like I have to work on the bending procedure next!

The great thing about this process is that it not only makes the cutting much easier, it is also very repeatable.  It’ll take some time, but you can end up with quite a few nearly identical parts using very few inexpensive tools, if that’s what you need.  No laser cutter needed!