Fanttik E1 Magnetic Bit Ramp — Gridfinity 2x2

A Gridfinity (2x2) stand for the Fanttik E1 electric screwdriver. The driver drops into the central tower, and 18 bits sit on a spiral ramp around it, each held by a hidden magnet: a bit dropped anywhere near its socket snaps home by itself, and comes out again with an easy pull. No friction fit to fight, nothing to wear out.

Printed and in daily use. Tested in both PLA and PETG. Prints exactly as oriented, with no supports.

How The Magnets Work

Every bit socket is bored straight through the part, except for a membrane just 2 layers (0.4 mm) thick. Under the membrane, a vertical channel runs down and out through the underside of the gridfinity base. A disc magnet pushed up this channel sits flat against the membrane, so the bit is held magnetically through 0.4 mm of plastic.

The channel tolerance is tuned so a 5x3 mm magnet goes in with slight resistance — once pushed up, it stays where it is, no glue strictly required. I use TWO 5x3 magnets stacked per socket, which makes the snap noticeably stronger; the channels are deep enough for the stack.

PS: My organizer works perfectly well without magnets, so you can print first and order magnets later :)

The Screwdriver Tower

The bore for the driver hides two small tricks:

1. The mouth has a rounded lead-in, so you can drop the driver in without aiming it funnels itself home.

2. The bore is very slightly tapered (0.28 mm on the diameter over its depth). As the driver slides down it gradually uses up its clearance and wedges gently to a stop about 5 mm ABOVE the floor of the bore. It never bangs into the bottom, and it sits snug, without wobble.

What You Will Need

• Neodymium disc magnets 5x3 mm: 36 for the default 18 sockets (2 per socket). One per socket also works, just with a gentler snap.

• Optional: a drop of CA glue per channel if you want the magnets locked in forever.

Printing

• No supports. Print as oriented, base down.

• 0.2 mm layer height. The membrane over each magnet is exactly 2 layers

• Tested in PLA and PETG.

• The only bridges are the small membranes over the magnet channels (about 5 mm each) any printer will manage.

Assembly

1. Turn the print over and push a magnet (or a stack of two) into each channel, flat face first, until it stops against the membrane. The fit is snug on purpose — a blunt rod or an allen key helps to seat it fully.

2. That's it. Add a small drop of glue into the channel mouth if you want them permanent.

Customizing (Openscad)

The OpenSCAD sources are included; they need the free BOSL2 library (github.com/BelfrySCAD/BOSL2).

• fanttik-magnet-simple.scad — the customizer edition. Only the parameters worth changing: number of bit sockets picked from a list (12 / 14 / 16 / 18 / 20 / 22 — all verified), your screwdriver's diameter and fit, your magnet size, and your layer height. Everything else is locked to the published shape.

• fanttik-magnet.scad — the full model, every design parameter exposed, with the design notes in the comments.

• fit-gauge.scad / fit-gauge.stl — a quick test coupon (about 20 minutes) with a through-hole at the bore diameter. Slide your driver through it before committing to the full print: it should drop through under its own weight without rattling. If it binds, raise driver_fit; if it rattles, lower it.

The defaults fit the Fanttik E1: 16.65 mm body, 5/32" hex bits. Other cylindrical drivers using 5/32" bits should work by adjusting driver_d.

Dimensions

• Footprint: Gridfinity 2x2 (83.4 x 83.4 mm), standard 42 mm grid with proper feet

• Height: 56.5 mm overall

• Default: 18 bit sockets, 12–22 via the customizer