Photobeam Gate Assembly Instructions¶

Parts and tools¶

Complete reference in module BOM.

item_id	category	description	quantity
`PRT-PBG-001`	3D-printed part	photobeam passage	1
`PRT-PBG-002`	laser-cut part	passage back cover	2
`PCB-PBG-001`	circuit board	beam gate controller PCB	1
`PCB-PBG-002`	circuit board	IR beam-break array PCB	2
`TBC-CBL-PBG-001`	cable assembly	Molex PicoBlade, 6-position, receptacle-to-receptacle, 600 mm	4
`FST-INS-M3-BRASS`	fastening hardware	M3 brass threaded insert for plastics	18
`FST-M3X6`	fastening hardware	M3 × 6 mm button-head socket screw	18

1. Prepare the photobeam gate¶

1.1 Prepare the housing¶

Inspect the PRT-PBG-001 photobeam passage for printing defects or residual material.
Clean all insert holes, PCB mounting points, and cable passages.
Inspect both PRT-PBG-002 back covers for damage or debris, and clear all mounting holes.
Identify the correct orientation of the passage and both covers.

1.2 Install the threaded inserts¶

Place PRT-PBG-001 on a flat, solid surface.
Install the 18 FST-INS-M3-BRASS M3 threaded inserts in their designated locations. Refer to the assembly video for positioning.
Keep each insert straight and press it fully into its seat.

Checkpoint: All threaded inserts are straight and fully seated.

2. Install the electronics¶

Connect two TBC-CBL-PBG-001 6-position PicoBlade cables to the PCB-PBG-001 beam gate controller. Push each connector fully into place while avoiding excessive force on the PCB-mounted Molex connectors.
Connect the free end of each TBC-CBL-PBG-001 cable to one PCB-PBG-002 IR beam-break array PCB.
Install the first PCB-PBG-002 on one side of the PRT-PBG-001 passage:
- route the connected PCB and cable through the passage;
- run the cable through the dedicated channel along the bottom of the printed part;
- orient the PCB so the emitter or receiver faces correctly across the passage;
- secure it with two FST-M3X6 M3 × 6 mm screws.
Install the second PCB-PBG-002 on the opposite side and secure it with two FST-M3X6 M3 × 6 mm screws.
Arrange the cable running along the bottom of the passage inside the dedicated channel. Use tape if needed to keep it in place. Refer to the assembly video for routing.
Position the PCB-PBG-001 controller on the upper outside surface of the gate, on either side, and secure it with the specified FST-M3X6 M3 × 6 mm screws.
Check that all wires have enough slack, with no sharp bends or tension, and that the two external connectors remain accessible from the selected side of the gate.

Checkpoint: Both IR beam-break boards are secure and correctly aligned, the controller PCB is mounted, and all cables are routed without tension or interference.

3. Close the photobeam gate¶

3.1 Install the back covers¶

Position both PRT-PBG-002 back covers on PRT-PBG-001.
Check that all cables remain inside their intended routing channels.
Align the cover mounting holes with the threaded inserts.
Secure both covers using FST-M3X6 M3 × 6 mm screws.

Caution: Do not use the screws to force the covers closed. If a cover does not sit flat, check the cable routing before tightening.

Checkpoint: Both covers sit flush and no cables are pinched between the housing parts.

Assembly video¶

Use this short visual walkthrough alongside the written instructions. The parts list, cautions, and checkpoints in this page remain essential.

Player unavailable? Open the temporary video in Google Drive.

Note

Temporary hosting: this Drive player will be replaced by the project's YouTube stream after publication; the released original will be archived on Zenodo. Google may request sign-in until public sharing is confirmed.