The stopper has a M4 counterhole. Simply mount it on top of the cheap 2020 belt tensioner. Now the carriage can't leave the rail anymore.
On the other end of the rail sits the x axis endstop to do the same.
The model was designed around the great mods from Kevinakasam (belted Ender 3, Frank 2.0 fan duct, the Y axis linear rail mod and the KlackEnder). Thanks for that!
Model printed with a 0.4mm nozzle and 0.2mm layer height in ABS.
The author marked this model as their own original creation.