Drive Hub Assembly

Drive Hub Parts

Time to assemble the drive hub. Use the star shaped servo horn that is included with the continuous rotation servo. The two screws used to servo the horn to the drive hub are M2.5 x 10mm flat head machine screws. A single M3 hex nut is used to anchor the string.

Screw Tap Holes

Depending on the size of the screws, you'll want to tap threads into the mounting holes. Place the servo horn over the drive hub and line up the mounting holes – This gives a visual reference of which holes to use. 

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Secure Hub to Horn

With the holes properly tapped and threaded, hold the horn and hub together while driving the screws through the mounting holes. I used flat head machine screws because the screw heads can be flush.

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Center Screw

The continuous servo comes with a few screws used for mounting. I picked one of the black ones and inserted it through the center hole of the drive hub. This will be used to serve the drive hub to the shaft of the servo. 

Install Rope to Hub

The drive hub has a 3mm diameter hole in the grove. It's for anchoring the rope to the drive hub. Insert the end of the rope and pull it through. Tie the end of the rope to an M3 hex nut (or whatever is similar) so that the rope gets anchored.

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Wind Up Hub

Give the rope a firm tug to ensure it's properly anchored to the drive hub. The geodesic sphere weighs ~1lbs (10 oz) so it needs to be able to manage that much. The groove in the drive hub allows the rope to wind up a few times before reaching capacity.

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Install Clasp

The other end of the string has the jumper ring. Go ahead and install a clasp – This will make it easier to clip it onto the roller assembly inside the geodesic sphere.

Install Hub to Servo

Grab the stand assembly and position the drive hub over the servo. Press fit the servo horn onto the shaft of the continuous rotation servo. Then, fasten the center mounting screw until tight – The hub will begin to rotate when its fully tightened. I suggest installing the hub with the rope outside the groove.

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Install Stand Cover

OK, now it's time to fit the box over the stand. To do this, you'll need to thread the rope through the center cutout in the center. Use the photo for reference. The cover will have to go over the 2020 extrusion. Insert the cover through the extrusion with it going through the center cutout (similar to the rope). Rotate the cover so the cutouts line up with the components. The cover is designed to snap fit onto the stand. Inspect the edges for any gaps or hanging wires, tuck them in if necessary.

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The rope should be accessible outside the cover with the clasp affixed to the end. 

This guide was first published on Dec 29, 2018. It was last updated on Dec 29, 2018. This page (Drive Hub Assembly) was last updated on Nov 30, 2019.