Axial EXO Terra Build – Part 8 – Electronics

The Build – Part 8
Installing the electronics in the EXO does require a little patience. Axial has included plenty of wire tie-downs to make sure none of your wires find their way into the drivetrain, but all this does require a little bit of time to do correctly. Take your time and you won’t have to do major surgery to repair any of it.

Build Notes:
The EXO can handle quite a bit of power. It can also accept a 540 or 550 size brushless motor! Special pinions will be needed if using a 550 size motor.

A special mount is included for use with the Novak Havoc ESC. This mount is not required with other ESCs.

While the receiver mounts in a water-resistant case, I chose to install Axial’s NVS lighting system in the same box. Doing this required the removal of the receiver box top, making my EXO non-water-resistant. I can deal with that for the absolute killer look the EXO now has.

The first step is to attach your motor to the aluminum motor mount. Simple and straightforward, but note that the wire tabs on the motor should be facing up.

Next, attach your pinion gear. A dab of loctite is suggested on the set screw. The slot at the bottom of the motor mount will allow you to feed the pinion deep into the mount and still tighten the set screw.

Slide the motor and mount into the chassis mounted motor mount. Screw the adjustment screw and set screw into the mount as shown. Do not tighten yet.

This close-up shows the lower adjustment screw and the upper set screw. By tightening the lower adjustment screw, you will widen the gear mesh between the pinion and spur. Loosening this screw will tighten the gear mesh. Set this screw so there is a very slight backlash between these two gears. Once you are happy with the mesh, tighten down the upper set screw. It does not say this in the manual, but I would suggest a DAB of loctite on these two screws to keep them from backing out.

For steering purposes, I’m going with Hitec HS-7955TG Titanium Geared servo. This servo has a monster 333oz of torque; perfect for the heavy duty driving this bad boy is about to endure!

Attach the servo to the servo mount as shown.

Before installing the servo to the chassis, feed the servo lead through the wire-capture-tab next to the front chassis brace as shown. This can be a bit tricky once the servo is installed.

Attach the servo and mount to the chassis.

Press the servo lead into the wire-slots located next to the receiver box. This is important!!!! It helps keep the wire away from the central gears.

Build the steering link. Axial’s recommendation of 25mm is spot on.

Choose the correct servo arm for your servo and attach one end of the link to it.

Attach the servo arm to the servo and connect the other end of the steering link to the steering bellcrank.

Your assembly should look like this.

Feed the pin through the rubber battery strap. The straps are a VERY rubbery, well, rubber, and will take a little coaxing to get them through.

Build a pair of battery holddowns. The battery straps have 3 holes in them for different size batteries. I started with the middle hole. Note the direction of the pieces.

Attach the battery straps to the chassis. At this time it is also a good idea to test fit the battery you will be using. Mine was a bit to big, so I had to rebuild my battery holddowns and use the lower hole. You don’t want to do this step after you’ve completed the EXO. Trust me.

Oddly enough, I will be using Novak’s Havoc ESC. I didn’t know that this ESC had it’s own special mount! This makes it easy as pie to install!

Attach the fan to the top of the ESC, the ESC to the mount and the switch to it’s separate mount. No tape required!

The ESC mount lines up with a pair of holes. Boom, done. Feed the wires from the ESC through the chassis mounted wire-ties.

Axial has also added another slick wire-tie on the rear chassis mount. Route your power wires from the ESC through here.

Connect the sensor wire to the ESC.

Solder the wires onto your motor. Remember, A goes to A, B to B and C to C. Mixing these up will result in your car going backwards. Really fast.

Even though my setup is a little different, I am showing you this step. Fit the rubber grommet over the receiver box. It might be a bit of a pain so a little bit of grease on the corners will help keep it in place.

Tape the receiver to the lid of the receiver box. Feed the wires through the lid and plug into the receiver. Attach the water-resistant foam and cap and install to the receiver box.

I added the NVS to the receiver box as shown. Yes, the wires are a bit of a mess right now but that will soon be fixed. This is mainly to show how the NVS was installed.

Feed the receiver antenna through the hole and slide up the antenna tube. Press the antenna tube into the hole and secure with the set screw.

Part 9 – Assembling the EXO cage.
Back to the Axial EXO Terra Build List