5mm D-Cut Shaft — every length: Voron 2.4 Z, Micron Z, V0 Belted Z, LH Stinger, ERCF v1.1 / v2 / v3

Hardened 5mm D-cut shafts for pulleys, gears, belted Z drives and ERCF gear rows: a ground flat the full length so the grub screw seats on steel instead of chewing a round shaft. Every length we cut, in one place. Pick by what it fits; the length is in the name.

Which length

• 60mm — Voron 2.4 Z drive, four per printer. The four-shaft set is the full printer.
• 50mm — Micron Z (the BOM's "5x47-50mm shaft, grind flat", four per printer; set here) and the LH Stinger Z stack.
• 72mm — LH Stinger Z stack, and the V0.1 Belted Z Drive mod, which calls for 72mm over 70mm to leave room for a metal 80T gear.
• 45mm — general stock. No current printer BOM we know of calls for it; it is the standard short length for a pulley or idler axle.

ERCF gear shafts

One shaft runs the whole gate row. The two ERCF generations use different lengths for the same gate count because v2/v3 filament blocks are 2mm wider than v1.1's. Buy the row that matches your build.

Lengths are the official BOM formulas (v2/v3: 72 + 23 per gate; v1.1: 70 + 21 per gate plus a 5mm spacer per three). The v2/v3 rows are also listed as ERCF v2 / v3 D-Cut Gear Shaft and the v1.1 rows as ERCF v1.1 D-Cut Gear Shaft; same shafts, same prices, same stock.

Specifications

• Diameter: 5mm, −0.02 / −0.03 (supplier drawing in the photos).
• Flat: 4.3mm across the flat (0.7mm deep), full length.
• Material: stainless steel, bright finish, not hardened. Exception: the four ERCF v1.1 lengths (159 / 201 / 269 / 337) are 12L15 free-cutting steel from the 2021 batch, so keep a film of oil on those.
• Lengths: 45 · 50 · 60 · 72 · 159 · 164 · 201 · 210 · 256 · 269 · 279 · 337 · 348mm.

What it is not

• Not a smooth linear rod: the flat is the point. The v1.1 lengths are plain steel; everything else is stainless.
• Not an 8mm rod. If your bearing bore is 8mm you want the linear rods.