All my piggy bank thickness are 3mm so this plug works ONLY for 3mm walls.

This is a piggy bank plug that I use for all my piggy banks that I've designed.  When you first insert the plug, it WILL be a tight fit.  You will need to do a few press fits to smooth out the plug.  You may need to lightly sand the opening to remove any jagged edges.  It is strongly recommended to do the test fittings BEFORE assembling both halves of the piggy bank (for my designs) as it can be hard to remove at first.  

If you want to use this for your own model, you are welcome to use it.

These are the dimensions that I use for it.

• 32mm circle cut through the bank
• 35mm circle at center point of 32mm circle and cut 1mm up
• 3x45mm rectangle at center point of 35mm circle. Cut through bank

Tree supports are required if hole is not laying flat on build plate. You will need to sand the hole a bit and do a few test fittings to smooth out the edges.