Motor Box Assembly

Motor Assembly

To start, we'll work on securing the DC geared motor to the motor housing. We'll need 2x M3 x 25mm long screws and 2x hex nuts. These screws are extra long to accommodate for the size of the motor body.

Install Motor Mount

Place the motor housing over the body of the motor and try to line up the mounting holes. The motor shaft should fit through the center hole. Can figure out which side of the motor to use? Try looking for the side with the protruding nub right below the motor shaft. While holding them together, insert and fasten the long screws through the housing and body of the motor. You may use a power drill to speed things up as they're quite long screws.

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Secure Motor

The screws should be long enough to protrude from the back of the motor. Place and fasten the hex nuts to the remaining threads and use pliers to tighten them in place. A third screw, (M3 x 25) can be inserted and fastened through the remaining mounting hold near the top of the motor shaft. This can be installed through the housing and tab on the motor.

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Drive Hub Parts

Set the motor aside and gather the drive hub parts and screws. We'll need the drive hub and the pin. 2x M3 x 6mm screws will be used to secure the two parts together. An M3 threaded insert and screw will be used to secure the drive hub assembly to the geared wheel.

Heat Press Threaded Insert

We'll need to install an M3 threaded insert into the center hole of the pin. I used the tip of a soldering iron to do this. Tack the pin down on a flat surface and place the insert on top of the hole. Slowly insert the tip of the iron through the insert and press down until flush. Be as straight as possible. Check all angles to ensure its installed straight. Allow to cool for a moment before refitting.

Installed Threaded Insert

The thread should be permanently secured in place. Test out the threads by inserting a short M3 screw. It should be straight and easy to fasten. We'll use this setup to secure the geared wheel to the pin. This will keep the wheel from flying off the track when in motion.

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Secure Hub to Pin

Start by inserting and fastening the two screws through the mounting holes on the pin. Flip it over and place the drive hub onto the screw threads. Both parts should be jointed at the flat surface. Screw heads should be recessed. While holding them together, fasten to join parts together. Use hex nuts to tighten and secure parts in place.

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3d_printing_motor-hub-nuts.jpg

The threaded insert is not present in the first photo but it should be there when installing!

Install Drive Hub to Motor

With the drive hub assembled, grab the motor and line up the hole in the hub with the motor shaft. Carefully press the drive hub onto the shaft of the motor. If it's too loose, the drive hub won't stay put. If it's too tight, it'll be very hard to remove. Options are to use a filing tool to loose up, or reprint with different slice settings. Using glue or other adhesives is also an option. 

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3d_printing_motor-hub-install.jpg

3d_printing_motor-hub-installed.jpg

Note, the motor housing has been removed in these photos for clarity – It should still be attached in your build!

Assembled Motor Box

The flange of the drive hub should be flush with the motor housing. If not, you may need to press the drive hub more to fully seat. With the motor box fully assembled, we can work on building the track next.

The threaded insert should be installed in your assembly!
This guide was first published on Aug 08, 2018. It was last updated on Aug 08, 2018. This page (Motor Box Assembly) was last updated on Aug 06, 2019.