LDO OTTOeject MK1 Kit — Open-Source Print Bed Automation Kit

Stop babysitting your printer. The OTTOeject MK1 — designed by Mikesh Patel (OTTOMAT3D) and manufactured in partnership with LDO Motors — is an automated ejection and plate-changing system that keeps your FDM printer running around the clock. When a job finishes, OttoEject ejects the completed print, then loads a fresh build plate and triggers the next job. No hands, no downtime.

True continuous production. The bottleneck in unattended printing is the person who clears the bed. OttoEject removes it: eject → reload → repeat. Built for print farms chasing throughput, but just as useful automating a single machine for overnight and batch runs.

Printer-agnostic. OttoEject is designed to pair with almost any FDM printer you already own, rather than locking you into a closed ecosystem.

Robust, proven motion hardware. This is a serious mechanical kit, not a gimmick: three LDO 42STH40-1684AC NEMA 17 steppers drive a GT2 belt and TR8×8 leadscrew system, running on an LDO linear rail plus LM8UU/LM12UU linear bearings and a rigid 2020/2040/2080 aluminium extrusion frame. Finished plates are handled and retained by an array of 36 N35 magnets for repeatable, positive plate changes.

Klipper-ready electronics. Control is handled by a BIGTREETECH SKR Pico paired with a Raspberry Pi Zero 2 W host, a dedicated PD power board, PCB-mounted endstop and included power supply — everything needed to drive the system out of the box.

OTTOengine software. The companion OTTOengine platform ties it together with smart queue management, print-job monitoring, and control of multiple printers and devices from a single interface, communicating directly with the OttoEject and your printers.

Genuinely open-source. Released under the Open Community License (OCL v1) — modify and remix the design within the licence terms, backed by LDO’s manufacturing quality and an active community.

What’s in the box

A complete self-assembly kitset (3D-printed parts not included), including:

• Electronics: BIGTREETECH SKR Pico control board, Raspberry Pi Zero 2 W, PD power board + cable, PCB-mounted endstop + cable, power supply
• Motors: 3× LDO-42STH40-1684AC NEMA 17 stepper motors
• Motion: GT2 belts (1 m + 1.2 m), GT2 pulleys & idlers, TR8×8 leadscrew with nut, LDO SLR12H linear rail, LM8UU & LM12UU bearings, POM wheels, 8 mm & 12 mm precision rods
• Frame: 2020 / 2040 / 2080 T-slot aluminium extrusions, cable chains, T-plates, L-plates and corner brackets
• Plate handling: 36× 8×3 mm N35 magnets
• Fasteners: full SHCS/BHCS/countersunk screw set, heatset inserts, roll-in nuts, washers and nuts
• Printed, illustrated packing checklist for parts verification

Specifications

More info here