The Axial EXO Terra buggy includes a very unique motor mount. The adjustable mesh screw and the dovetail groove are both unique designs for ease of adjustment and maximum holding strength with minimal effort.
Lets go over the basic installation and assembly of the motor mount.
Step 1: With the motor mounted onto the slide use this screw to adjust your mesh. You can slowly adjust the mesh as you tighten or loosen this screw, once set you will be able to remove the slide with the motor attached and install it again into the same exact position. Use a 2.5mm allen driver for this adjustment screw.
Step 2: Once the mesh is set install the M4 set screw in the top of the motor mount. Do not tighten this screw all the way down yet. Use a 2.0mm allen driver here.
Step 3: Continue tightening this set screw, you will feel the screw stop once it hits the motor mount slide shown by the green arrow on the step 3 image above.
Step 4: Once the screw has touched the motor mount slide you only need to turn it another 1/4 turn. Or 90*. This will snug up quickly and lock the motor slide into place. Over tightening this set screw will cause damage to the motor mount or the motor mount slide. 1/4 turn is all you need here.
DO NOT OVER TIGHTEN THE M4 SETSCREW! YOU WILL DAMAGE THE MOTOR MOUNT.
Here is an image from Step 22 in the EXO Kit manual. You will see the slide attached to the motor, and the motor mount attached to the chassis.
**Worried that the extra 1/4 turn past snug isn’t enough? Here is why it works.
The Motor Mount has a male dovetail, while the motor slide that the motor mount attaches to has a female dovetail. When the M4 setscrew is tightened you are not only applying pressure to the point of the set screw, but also to the entire surface of that dovetail. This increased surface area means you have that much more material holding the motor slide into place. Trust the surface area! Over tightening the set screw will actually decrease this surface area and potentially break the mount. AGAIN, DO NOT OVER TIGHTEN!
Here is an image of the added surfaces from the dovetail. This is holding the motor mount slide into place. Keep in mind these surfaces are on the front and back.