Front chassis
Now it’s time to combine the prepared Nose with the rest of your front chassis. To do so, use M3x15 screws, washers and nuts. You need six screws, six nuts and 12 washers for each side.
Bumper trigger
As already mentioned, the front chassis acts as bumper to detect collisions with obstacles. This gets detected by micro switches you already placed in previous steps. To trigger these switches, a small printed part called “bumper trigger” needs to be mounted to the front cover. To do so, first insert two brass nuts on the inner side of the front (see picture). Use two M3x5 counter sunk screws to fix the trigger
Special note about bumper trigger
Depending on the type of micro switches you use, you may need to adjust the 3D file of bumper trigger. You will need some iterations to get a good working geometry, but it shouldn’t take long to figure this out.