MB17 Numpad Build Guide
1) For this build you'll need a soldering iron and flush cutters. I like to use helping hands to hold things in place while I'm soldering, but you don't need them to get this done. The picture below shows everything included in the kit.
2) You will need to supply your own solder, MX switches, keycaps, and micro USB cable. Make sure that your cable can transmit data and isn't just for charging. If you're new to the hobby and don't have any keycaps for a numpad, Signature Plastics is a US based keycap manufacturer that has a bunch of numpad sets in stock.
3) Bend your diodes as shown. It helps to find or make something 7mm wide to use as a tool to bend the diode legs over.
4) Insert the bent diodes in the PCB so that the black stripe on the diode faces the white stripe and square pad on the PCB. I like to solder from the diode side. Feel free to solder from the top of the PCB if you prefer to do it that way instead, but you'll have to either tape the diodes in place or bend the legs out before you flip the PCB over to solder.
5) Clip off the diode legs with flush cutters.
6) Next we're going to solder in the reset switch. You can skip this step if you're not comfortable with surface mount soldering. The board will work fine without it, but it will make resetting the pro micro much easier.
Apply a small blob of solder to two of the pads and then hold the switch in place with tweezers while you melt the solder on one of the pads as shown below. Now the switch should be soldered down to the PCB. Melt the solder on the other pad and then apply solder to the other two pins.
7) Solder in the headers for the pro micro. The shorter pins go in the PCB. Start by soldering just one pin on each header and then flip the PCB over to make sure the headers are in straight. Bend them if needed before soldering the rest of the pins. Don't solder in the Pro Micro yet! You need to do the switches first.
8) Clip, lube, and assemble your stabilizers. I'm not going to go into the details of how to do this but here's a guide written by Quakemz of Top Clack. You can skip the bandaid mod part ;)
Insert the stabilizers as shown and screw them in from the bottom. Go easy on the screws since they'll strip out easily if over tightened.
9) Now it's time to solder in the switches. Start by placing switches into the four corners of the plate and solder those in to get the plate aligned with the PCB.
10) Press in and solder the rest of the switches.
11) Place the pro micro on the header pins as shown below and solder all 24 pins.
12) Use the flat screws to attach the standoffs to the base plate and then stick on the bumpons.
13) Use the brass screws to attach the plate to the standoffs, throw on a set of keycaps, attach your cable, and you're done!
The included pro micro comes pre-flashed with a basic numpad layout so unless you plan to remap the keys you are good to go. If you do want to remap your keys all you need to do is download and install VIA, open VIA, and connect your MB17.