Thrustmaster T150 Sequential Shifter Addon

This is a sequential shifter addon for Thrustmaster T150 wheel which uses L3 and R3 buttons on the wheel's base for operation. It's a purely mechanical solution - no soldering (at all) or modifications (almost) needed. Some additional hardware is needed to assemble it though:

Countersunk self tapping screws:
1x M4x16
1x M3x25
1x M3x16

Bolts:
2x M3x30

Screws:
1x M10x120 outer hex head
1x M3x10

Washers and nuts:
4x M3 washers
1x M10 nut

There are versions of 2 “spring”: one to be printed in TPU and another in any other somewhat flexible material (PETG/ABS should work - PLA not so much). Printing from TPU is prefferable as other materials would break over time due to repeated stress.

“rocker”, “handle” and “spring” parts should be rotated to lay flat on the bed (for strength along correct axis and printing without supports)

“base” should be printed with at least 4 perimeter walls (and preferably more) to be suitably stiff

Assembly instructions:

1. Screw out the screw on the wheel base bottom which is closest to the right side of the wheel base front plate (where L3 and R3 buttons are located)
2. Pass M10x120 screw through “handle” part so that its head slots into hex cutout, screw M10 nut from the other side to secure (not too tight for now)
3. (OPTIONAL) Screw the handle assembly from the previous step in and out of “arm” part to work in the thread in it a little bit (so it's easier to assemble later)
4. Screw M3x10 through the hole on the small arm of “rocker” part coming from the outside of the part - the screw should stick out from the other side for about the height of the part after that
5. Pass M3x30 through the small hole in “arm” part (be sure to add washer on the both ends of the hole!) and screw the whole thing into one of the long vertical holes in the “base” part ("arm" profile should line with “base” profile if positioned correctly). Do not overtighten! “arm” should be able to rotate around M3x30 bolt freely (but shouldn't rattle up/down).
6. Pass M3x30 through the small hole in “rocker” part (be sure to add washer on the both ends of the hole!) and screw the whole thing into the other long vertical hole in the “base” part (M3x10 screw in “rocker” part should pass through the slot in the “arm” part). Do not overtighten! “rocker” should be able to rotate around M3x30 bolt freely (but shouldn't rattle up/down).
7. Use M3x16 screw to secure “spring” part in the slot on the right side of “base” part
8. Screw “handle” assembly into the “arm” part until secure (passing through “spring” loop). Handle might be misaligned after that - undo M10 nut, move M10x120 from the slot in the handle, reposition as needed and screw M10 nut back
9. Secure the whole thing on the right lower corner of the wheel base. M3x25 should pass through the smaller remaining hole in the “base” and screw into the hole from which a screw was removed in step 1. M4x16 should through the bigger remaining hole in the “base” and screw into one of the vent holes aligned with it. These two screws should be tight enough so that “base” does not move relative to the wheel's base, but not too tight so that plastic thread in the wheel base doesn't strip.
10. Assign L3 to gear down and R3 to gear up in the game's options.
11. Have fun.