Why TPU?


TPU stands for Thermoplastic Polyurethane. It is an advanced elastomeric polymer used in 3D printing that behaves like flexible rubber. Unlike rigid plastics (like PLA or ABS) that crack or snap under sharp stress, TPU can bend, stretch, twist, and compress under heavy pressure, then instantly spring right back to its original shape.

Why We Use TPU for Our Metal Detecting Bumpers

Metal detecting involves pushing your coil through rough terrain, rocky soil, brush, and abrasive sandy environments. We use 3D-printed TPU for our search coil and control box bumpers because it offers unbeatable real-world benefits:
  • Superior Shock Absorption: TPU acts as a cushion for your coil. When your search coil bumps against rocks, tree roots, or buried debris, the TPU bumper absorbs and disperses the impact energy instead of transferring the shock to your coil’s plastic housing. 
  • Abrasion & Wear Resistance: TPU is highly resistant to heavy scrapes, cuts, and gouges. Sliding your coil across abrasive gravel or rocky ground won't easily chew through the material.
  • Snug, Secure Fit: Because TPU has a slight rubbery grip and controlled flexibility, the bumper stretches slightly during installation to lock tightly around the edge of your search coil—meaning it won't slip, rattle, or fall off while you swing.
  • All-Weather Durability: TPU resists oils, grease, and weather extremes. It won't become brittle in freezing cold temperatures or degrade under intense summer heat and UV exposure.
  • No Interference: TPU is a non-conductive plastic, meaning it adds zero metal interference or false signals to your detector. 
  • Easily Renewable: Constant ground friction can eventually wear on the 3D-printed layers at the exposed bottom edge of search coils. If that ever happens, you don't need a new bumper—just glide a warm soldering iron over the worn edge to instantly fuse the layers back together and make it function as good as new.
    • Quick Tip: Set your soldering iron to a low heat (200°C–220°C) and use light, smooth strokes to iron the surface layers together. If you have a flat or chisel tip, use it like a tiny spatula to make this process even faster and smoother!