This was one of my projects for Sugru hack night with maker group HackBergen http://hackbergen.no.
- 2 packs of 5g Sugru
- 1 sheet of 2mm Craft Foam
- IKEA HDPE 8mm Cutting board
- Masking tape
- Mild soap
- Super Glue
- Computer with G Code drawing tool - iMac w/VirtualBox running W8 and Vectric Cut2D
- DIY CNC mill - Shapeoko with 2mm ball edge mill bit, and Ubuntu PC running Universal G Code Sender
- A small straight edge screwdriver
- 400 grit sand paper
Step 1: Mill a Mould From HDPE Cutting Board
1.5mm base depth with an extra 1mm milled out to make the decorations (ridges).
1000mm/min feed rate, about 25,000 rpm spindle speed, and a 2mm ball edge end mill bit.
Step 2: Clean the Mould and Apply a Fine Layer of Soap
Apply a thin layer of soap to the mould so the Sugru will not cement itself to the HDPE.
Allowing the soap to dry first will make it easier to avoid blending soap into the Sugru itself.
Step 3: Knead Together 2-3 Packs of 5g Sugru
You might need 3 packs since only 2 packs was barely enough to thinly cover everything. Here it helps to have the same color foam as the Sugru. Then tiny holes in the Sugru do not show so easily on the finished product.
When you have the mould filled, use mild soapy water on your fingers to be able really smooth it out evenly.
Let the Sugru harden for 24h.
With water, gently rinse the cured Sugru of the soapy residue to assure that the super glue sticks.
Step 4: Mill Craft Foam That Fits Into the Coaster Mould
There is no need to initially cut it out perfectly since the rough edge will need to be trimmed away anyway after it is glued to the Sugru and released from the mould. So as long you cut it out 3-4 millimeters larger than the coaster itself, you should be ok.
Step 5: Gluing the Foam to the Sugru
I had some difficulties finding a glue that would stick to both Sugru and craft foam. I tried using just the Sugru alone, plastic glue, hotgun glue and contact cement, to no avail. Finally, Super Glue to the rescue!
Apply a fine layer of super glue to the dry Sugru and press the foam onto it.
Try not to get glue on your fingers, but if you do - keep them apart! The glue can be sanded off your finger or it will fall off by itself in a couple of hours. Disposable gloves could be used, but I find that they stick to everything and make it difficult to work quickly.
Step 6: Gently Remove the Sugru/Foam From the Mould
Step 7: Cut Away the Tape and Excess Foam
Let the Sugru cure completely before placing anything on it. I let it dry for another 24 hrs.
Congratulations! Now you have yourself a custom made coaster!