The Qanba N1 arcade stick comes with a circular gate. However, for most people a square or octagon gate is better especially for fighting games. The type of restrictor plate is a very personal choice but some have advantages over the other. The square is probably the most common while the octagon is gaining popularity. The circular gate is great for fighting games like Street Fighter that have a lot of 360 circular motions in their move set, like Zangief's pile driver move. While people who use Ryu or Ken might prefer square or octagon plate. In this instructable, I'll show you how to 3D print and install it in the N1.

Qanba N1 Arcade Stick Joystick Controller PK Machine
https://goo.gl/ozdkTZ

Qanba N1 3D printed restrictor plates
https://www.thingiverse.com/thing:2804740

Youtube video (restrictor plate starts at 4:05)

Step 1: 3D Print

I 3D-printed this on my Da Vinci 1.0 printer at 0.2mm layer height using ABS filament. I sliced it with Simpify3D but any decent slicer should be able to do it since it's a very simple model. Get the STL on Thingiverse.

Qanba N1 3D printed restrictor plates
https://www.thingiverse.com/thing:2804740

Step 2: Taking Apart

To take apart the arcade stick, first take off the ball top. There is a compartment at the bottom that allows you to stick in a slot screwdriver in there to hold the stick in place as you screw off the ball top.

Then there's 6 screws that hold the top panel in place. 4 screws are under the the suction cups, another is under the white circular sticker and the 6th screw is on the bottom below the rectangular sticker.

Step 3: Remove Joystick

To get access to the restrictor plate, remove the 4 black screws. Then flip the joystick around to reveal the original restrictor plate. It's held down with 4 more silver screws.

Removing the circular gate will review the switches.

Step 4: Replace Restrictor Plage

Just pop in the newly 3D printed restrictor of choice and screw it back in.

Step 5: Finish

Put everything back together and enjoy your new restrictor plate. Check out my video for more detailed information.
Youtube video (restrictor plate starts at 4:05)