We have received our first batch of 9 kits back from our kitter, and these kits have all passed our First Article Inspection (FAI). Of these 9 kits, 8 will go out on Wednesday to early bird full kit backers, the remaining one, after a brief photo shoot for additional kitting documentation, will head north to Canada as the second engineering evaluation unit kit for our friends at Solarbotics.
Earlier tonight, I've also finished the electro-mechanical systems integration for the Brainwave Pro test fixture:
Mike over @ Z-Designs have been testing each outgoing board individually. It is a slow and labor intensive process, especially hooking up the relatively high current connections for power and HBP. We don't just look for a red blinky light when we ship a board - we actually load firmware, and run a G29 auto levelling routine and heat up the hot end and heated build platform before flashing the firmware meant for the particular printer kit onto the board before sending it out the door.
Obviously, having a design engineer spend 15 minutes per board to test it is a big no-no. (It also is a big road block to being able to ramp up shipping of the kits - and our goal is to ship all the kickstarter rewards and most of the preorders this month). So, we built a custom bed-of-nails test fixture. When the panini-press mechanism opens, you can see the board under test:
The board is guided into position by two ground steel pins that grabs it by the screw mounting holes. We use drill blanks, as they are ground to a really precise diameter and we hand grind the round profile on a grinding wheel so it doesn't snag the edge of the PCB.
Underneath, a spring loaded plate protects the pogo pins. When the Panini Press closes, it presses down on the plate and the pogos make contact:
Early on in the Brainwave Pro's design process, Mike and I sat down and came up with a test protocol. We made a list of what we would like to test, and for certain functionality we added test points to the board that can be accessed by this bed-of-nail tester. For example, we broke out a test pad for the Vref for all the stepper motor driver chips, so that we can adjust the holding current on this fixture. (The top of the Panini Press also acts as a screw driver guide, and just to be sure, we will be issuing a ceramic, non-conducting screw driver to our kitter just to make sure we don't accidentally short something out.
It's no coincident that all the cables coming out emulate the Brainwave Pro's output connectors. It is a design decision - this allows us to take any production printer, disconnect the board, plug the motor / end stop / end effector connections into our test fixture, and use that combination as our production test fixture.
Mike will continue to manage fulfillment, and occasionally I'll step in to make sure that the supply chain stuff is going ok. Meanwhile, I will switch my focus on the kit assembly documentation.
Still lots to do, but we are getting there.
-=- Terence & Mike.