The LumenPnP mission
On the subject of assembling PCBs at house, there are two essential approaches: both inserting every element by-hand with a pair of tweezers or utilizing a CNC machine. In each instances, somebody is required to place down a layer of solder paste onto the SMD pads in order that every part will turn out to be electrically and mechanically linked when reflowed. However for Stephen Hawes, the founding father of Opulo and creator of the open-source LumenPnP pick-and-place machine, he needed to skip this tedious step and as an alternative delegate the duty to his automated system.
Extending a earlier idea
Again in September, Hawes was experimenting with a solution to place parts onto a powered PCB and have every LED illuminate the second it accomplished the circuit. For it, he sourced a extremely conductive ink that, though not practically as safe as solder, would obtain the aim. Subsequent, the ink was positioned into syringes and examined manually earlier than Hawes ran a pick-and-place job on the machine.
This ink-dispensing implementation impressed him to develop a brand new toolhead for shelling out solder paste, and it required a couple of modifications earlier than it might be used, because the paste’s elevated viscosity requires much more torque than ink. One run of the 3D printer later and Hawes had his new-and-impoved shelling out toolhead prepared for testing.
As soon as he was assured within the idea, he designed an improved model with the next gear ratio and bigger motor.
Utilization with a Lumen pick-and-place machine
The LumenPnP, owing to its open-source nature, is controllable from Python scripts through a library known as leash. With it, the machine’s place, lighting, toolheads, and cameras can all be managed, which is how Hawes was in a position to automate his solder paste dispenser. After coming into the coordinates of every floor mount pad and instructing the machine to house, it iterates by way of each pad within the record by touring to its place, feeding the dispense motor for a small period of time, after which retracting upwards for the following pad.
Outcomes
The addition of a paste dispenser makes the LumenPnP able to practically 100% end-to-end autonomy and helps guarantee the right amount of paste will get deposited on every pad. Sooner or later, Hawes plans on bettering his software program to robotically generate pad coordinates from PCB design recordsdata and cut back his manufacturing time even additional. To see the machine in motion and the way Stephen developed his time-saving toolhead, you possibly can watch his video right here on YouTube.