Backbone One Gen1 Tablet Expander

Printing Recommendations

• 0.4mm nozzle
• 0.12mm layer height, 2 walls, 15% infill

Materials you will need

•  Flexible Flat Cable, 18 Pins 0.5mm Pitch 400mm FPC FFC Flexible Ribbon Cable [Amazon]
• ¾" Kapton Tape [Amazon]

Backbone One Tablet Expander

This expansion allows you to use a tablet with your Backbone One controller to accept a tablet size up to 292mm in width. I have personally tested it with a 10.95" Pixel Tablet and a 12.9" iPad Pro.

I have plans to create a magnetic adapter that will better hold an iPad, but I have been able to use this with the larger (and heavier) iPad without issues.

Out with the old

1. One side at a time, remove the screws from the back of the controller. Be careful of the spring in the controller, it can easily be dislodged and fling the rod and sheath inside everywhere. Ask me how I know.
   
    
2. Carefully separate the cover from the base and set to the side. Release the tension on the spring by lifting it out of the socket with a pair of tweezers. Once the tension has been released on the spring, remove the screw securing it to the expander.
3. Remove the cable(s) from the cover.
4. Remove the screws securing the controller from the expander.
5. Repeat steps 1 - 4 for the other side.

Assembling

1. Assemble the rack arms pinion gear on the base plate (ensuring the counter sink holes are facing upwards).
   
    
2. Folding the cable
   • Find the center of the cable (do not crease the cable but marking is fine) and place it roughly on the center of the template with the metal contact sides facing up. Ensure that the cable is fairly centered at 75mm of cable overhang on each side.
   • Holding the cable in place, fold the top left side down at a 90° angle.
   • Fold the other side of the cable under itself in the channel with the metal contacts facing up.
     
      
3. Mounting the cable on the underside of the cover
   • To assist with centering the cable on the cover lid, center the cover to the base ensuring that the sides of the cover align with the inner cover supports of the base.
   • Place the folded cable on the center of the cover (with the folded center in line with the gear of the base), metal connection side down as shown in the image below and secure with kapton tape.
   • Secure the sides of the cables with kapton tape and then a full piece of kapton tape across the entire cover channel
     
     
      
4. Place the cover on the base and align the cover edges with the inner cover supports of the base. Be sure to align the thicker edge of the cover with the thicker edge of the plate. Starting at one side, apply even pressure on the edges of the cover to “snap” the cover into place. I find it easiest to start at one side of the cover and gently slide my finger across the top of the cover and then flipping the cover over and applying even pressure to fully seat the cover in the base.
   
    
5. Installing the expander
   • The expander should fully replace and align into the original holes of the controllers.
   • Secure and re-set the springs (be careful; they are ornry little buggers)
   • Secure the cable(s) with the metal contacts against the circuit board connectors (I recommend putting a piece of Kapton tape over the ribbon connector)
   • Gently fold the cable in on itself in the cable channel making sure not to fold or crease the cable.
6. Once the side has been fully assembled, install the 4 screws and repeat the process on the remaining side.