Magnetic spray painting tray

The tray is a grid of magnet pockets with an extra one in the middle of every four, so bases of different sizes can always find a magnet. The handle is a separate part that glues to the middle of the underside, where there's an engraved + to line it up, so neither part needs supports.

The STLs are a 174×174mm tray with 25 pockets for 5×2mm magnets (a 4×4 grid plus nine in between), and the handle in all four grip shapes at 100mm long: round, oval barrel, flared base and pistol grip. Print the tray and whichever grip suits your hand.

You'll need neodymium magnets (5×2mm, 25 for the tray) and superglue or two-part epoxy for the magnets and the handle.

For other grids or grips, open spray-tray.scad in OpenSCAD and use the Customizer panel (Window › Customizer). It needs a recent development snapshot of OpenSCAD (2024 or later), because the 2021.01 release is too old.

What you can change in the .scad:

• Magnet grid: columns, rows, centre spacing and edge margin

• Tray thickness

• Magnets: size and clearances

• Handle: round, oval barrel, flared base or pistol grip, with length, width, lean, a rounded end and ribs

This is part of HobbyKit, a free generator I made. hobbykit.app does all of this in a browser, and can also give you a 3MF with the tray and handle on separate plates, ready to slice.

Print settings

• Tray: flat, pockets facing up

• Handle: upright on its flat end

• No supports for either

• 0.2mm layers

• PLA or PETG

Assembly

1. Glue a magnet into each pocket, flush with the top.

2. Glue the handle's flat end over the + in the middle of the underside.

Files

• spray-tray-4x4-174x174mm.stl: the tray, 174×174×3mm, 25 magnet pockets

• spray-tray-handle-round.stl: round grip, 28mm across, 100mm long

• spray-tray-handle-oval.stl: oval barrel grip, 100mm long

• spray-tray-handle-flared.stl: grip with a flared base, 100mm long

• spray-tray-handle-pistol.stl: pistol grip, 100mm long

• spray-tray.scad: the OpenSCAD source for other grids and grips