Documentation of the SRT V9.1 gearbox

I am working on a 6 speeds gearbox that would be controlled by an hydraulic clutch pedal !

Summary

1) Presentation

2) How to start

3) Shopping list

4) 3D files

5) Assembly

6) Arduino Code

7) Wiring

8) Mods

1 )Presentation :

The best gearbox in the world:

• 6-speed H-box + reverse gear
• Sequential (we go from one to the other in 3 seconds)
• Clutch mode (optional): if you don’t press the clutch pedal, the gearbox stays locked (only in H mode)
• Multiple attachment points (from underneath and from the side)
• Adjustable front-rear and left-right feeling
• Adapter to mount a hand brake (P1)
• Possibility to connect pedals to it
• For about 220€.

The documentation of V9.1 is available on this page.

All the documentation is available on this page. Do not hesitate to ask for help on the Discord!

2) How to start

3)Shopping list

The shopping list is available here.

4) 3D files

The 3D files are available on this page. There is only one version of Body2, which is designed to support the eClutch mod. The eClutch mod and its shopping list are documented separately, see 8) The Mods

The body1 is available in two versions : one is compatible with the handbrake mod.

Each file contains a printing instruction in the form xx-xx. The first number is the precision, the second the filling. For example 02-30 means accuracy of 0.2 and filling at 30%. It is also useful to double the thickness of the walls.

The word “support” indicates that supports are required… The number that follows is the overhang angle to be entered in Cura.

I also recommend to activate the adhesion to avoid warping (part that comes off the support).

I recommend using the Cura slicer.

All the parts are in the ideal orientation for printing.

You will also find a step file which will allow you to integrate the cylinders in your CAD.

Beta: due to my recent troubles with my printers, I was not able to finalize the PCB cover.

I couldn’t refine the tracks either. You will find for the moment only one sequential track and 5 H tracks which correspond to the “neutral” of v9.0.

The turn is temporary: I haven’t defined yet if I’m going to use two or three rods to reduce the friction.

5) Assembly

Once all the parts are printed, you can start the assembly by following this tutorial.

6) Arduino code

The latest firmware is available on this page.

7) Wiring

It’s not essential, but here is the detailled wiring of the Arduino Micro :

8) The mods

Each mod has its own dedicated documentation. It is recommended to start by making a box without mods before adding mods.

• The eClutch mod : https://lebois-racing.com/mod-srt-eclutch-for-the-srt-gearbox
• The button plate mod : https://lebois-racing.com/mod-button-plate-for-srt-gearbox
• The gear indicator mod : https://lebois-racing.com/mod-gear-led-indicator
• The button box mod : https://lebois-racing.com/mod-button-box-wip-2
• The Joystick mod : https://lebois-racing.com/srt-gearbox-joystick-mod
• The handbrake : https://lebois-racing.com/handbrake-mod

You can also find all the mods developed by the community in remix of the project on Thingiverse.

A particularly popular mod is the one by Anthoneuh which allows to block the lateral movements of the lever in sequential mod.