In addition to the 3D printed parts, you will need a variety of electronic components. I was able to order most parts online from Amazon. Here is what you are going to need. All prices are in US dollars at the time I wrote this, based on a quick internet search. You may be able to get better prices by shopping around or ordering from specific sellers or buying from a local electronics shop.

1 Teensy 3.6 ($36) or ($45) with pins. Order it with pins unless you want to solder them yourself in which case you will need 48 "male pin headers." For this project you don't need headers on all the holes, just the two outside rows.

1 USB 2.0 A Male to Micro B 5-pin Male cable. ($4) Many people have one of these lying around already so you probably already have this. This will be what you use to connect the control box to the computer, so make sure that you get a length that will work with your setup.

5 "male pin headers" to replace the pins on the mini joystick so they point the way we need them to.

1 PSP 1000 Analog Joystick ($8)

23 keyboard keyswitches. ($40) or ($10) These come from a variety of manufacturers and in a variety of different colors, which correspond to different characteristics. I ordered mine for less than $10 for 40 by shopping around and ordering from a re-seller. Online keyswitch re-sellers often run out of popular switches, so if the site you are looking at doesn't have what you need, check a few other sites and you should be able to find what you are looking for. It doesn't matter if you get the plate mount type or the PCB mount type for our purposes, but the plate mount may give you a little extra room when you are soldering, so if you need to choose between different ones, you can use that as a tiebreaker and go for plate mount type.

23 Keycaps ($0) to ($40+). If you search online you can find 3D models to print your own keycaps on thingiverse or other websites at no additional cost. You will need a total of 23 keycaps for the box. I was able to find two 12-key number row plus "-" and "+" key sets on clearance from an online store that gave me 24 keys for $15. Some places sell novelty keycaps for as much as $5 each, so this could get really expensive if you let it. If you have an old mechanical keyboard, or find one at a thrift store, you can cannibalize the keycaps if it is the right kind of keyboard. You will know because the right kind have a + shaped hole in the back if you pull them off and turn them over. I recommend that you print them yourself if you can't find a deal.

6 "uxcell 4 pin tactile momentary 12mm x 12mm x 8mm switch with cap" ($5 for 10) If you want to substitute for a different cap or button style, it should still work as long as the base is the same size and shape, with the same pin placement. There are some that have round buttons. The square button caps often sit a little crooked since they wiggle, so if you are bothered by that, you may want to give the round caps or cap-less ones a try. Just be sure to look at the height before you order. I wouldn't recommend anything less than 8 mm, but you might be able to go up to 12 mm and still be comfortable.

1 "10x10x9mm 6 Pin 5 Way Momentary Square SMD SMT Tactile Switch" ($9 for 5)

1 "FICBOX Dual-axis XY Joystick" ($9 for 5) Other brands might work just fine, but I designed this around this brand, if the alignment or size of the board you get is different they may not fit properly.

3 feet of 22 gauge solid hook up wire. ($10 for 100ft) Shop around or visit a local hobby store, you don't need nearly that much.

38 male to female jumper wires 20 cm length. ($7 per 120) These often come as "ribbons," that's just fine, and you can peel them apart as necessary.

6 female to female jumper wires 20 cm length ($0 - included in the above set of 120 if you buy a variety pack)