Drive System Part 7: Outer wheels

Bolts are everything :)

Gave up waiting and went to Home Depot to purchase M6 X 40mm bolts... they didn't have any left and had 50mm instead.  So I purchased those... what the heck little long...

Finding not a lot of room and not easy to remove the drive carriage from the cheese wheel and its very hard to get in there to work... might need an angled screw gun (small) for the future work.

This stuff is expensive... 1.29 per?!?!  X 8 is $10.00 easy.  The bolts are Philips head round button tops. they didn't have flat top bolts.

you can see the bolt a little high through the assembly arm where the wheel is.

Got one side completed... now to flip it over.  Note:  Had to angle the carriage so it exposed enough of the underside of those arms so I can screw the bolts through the bottom.

Both sides are completed and it fits like a glove.

Good close up of the wheels installed.

Head Mechanicals: Part 1 Gimble Assembly

Gimble Assembly defined

The gimble as its term implies is a mechanical device that rotates as well as moves around 20 degrees in any direction allowing the dome head to move around on the top of the ball / cheese.

The gimble consists of 1 central 180 degree servo that will rotate the head, 2 BB+ servos (hi torque) that will push and pull the gimble body around thus moving the head on the larger ball.

The end of the gimble consists of a casing holding N52 magnets that are strong enough to hold up to 50lbs of weight.  The dome head will have 3 other N52 magents that will pull against it to hold the dome onto the body as it moves around.

The assembly minus the body and head areas as shown above.  This assembly will magically move and turn the dome around on the body.

Started the assembly with the printed parts from back in June 2016...

The gimble body pieces connected don't allow too much room for the bearings... this will require either:

1. Boring out the bearing holes
2. Purchasing smaller outer diameter bearings

Here is another look at the bearings and their fitting between the two halves...

You can see the seam there due to the bearings being too large on the outer diameter.

The inside bearing... and the seam

A hitec servo will turn the dome's head from inside the gimble.

The tension cady connects the 8mm rod from the dome magnet assembly to the servo via the hat that connects to the servo gear ratio.

Another view of the servo 8mm rod that will drive through the magnet assembly

Drive System Part 6: Lower wheels

The correct size wheels (130mm) finally came in!

With these parts I am able to assemble the under wheels that the entire drive carriage rolls on inside the cheese.

Attaching to the connectors, I then use nuts (6mm) to keep the wheels in place, and then locking the end in with 6mm lock nuts.

Will need 4 of these total to connect the lower wheels, I may need to add additional to the outer top areas as well... we shall see.

Slipping the 130mm 6m bolt through the first

Sliding the wheel down the bolt (the wheels have a built in bearing assembly) locking first into place using the 6mm nut

Adding an additional nut, adding the wheel and running that through the other end.

Here is a good look of the nut pushing the wheel against the other connector.

Finally adding these to the carriage itself... and placing inside the cheese frame.

Placing the assembly inside the cheese was very tight.

Almost there... need to add the outer wheels and then run power through the drive motor to see how it runs.

Drive System Part 5: The Trousers - Gyro Assembly

More measurement mishaps

The bolts (#8-32 X 1 1/4") that connect the 14" lazy susan bearings to the harnesses that go around the trousers were slightly too short.  I need roughly another 1/4" or more to connect the nuts.

The bolt comes through but not enough to have a nut bite onto them

Here is a shot of the hole alignments for the trouser braces

Also the treads that are being used to grip the main drive and the gyro tilting pieces are loose and slip on the hubs... may have to glue these into place.

Using #4x40 X 7/8" screws  to fasten the main assembly for the trousers

The alignments need to match in order for the second drive to fit snug

Counter sunk holes keep the screws from being exposed and allows better support to the main assembly

Completed assembly of the trousers for supporting the gyroscope or gyro.

Loose check of the trousers with the 1/4" pipe assembly into the banana or drive system.

Another view of the assembly... with the drive installed for supporting the gyro.

I glued using weld-on 16 the main gear to the main drive assembly... the fit was snug and the I ensured the gear was level.

Here is another view the gear track mounted to the main drive.

Assembled the drive wheel gear that will run along the track that essentially causes the whole trouser assembly to rotate 30 degrees either way.  This will allow BB8 to turn while moving forward or backward similar to a motor cycle banking.

Another view of the preliminary assembly for fitting purposes.

Another close up of the gear and track fitting or placement... will need to adjust as I assemble and fit the gyro.

Another view of the gear to the track.

Drive System Part 4: The Banana - drive harness

Skipping ahead a bit

Until the 40mm and 130mm M6 bolts arrive from china... started forward with the ends and gyro (trouser) assemblies.

Connected the end rail holders using #4x40 1" screws... each one needed 2 into each side to hold it solid.

Loose fitting the 1/4" pipe into the sleeves and verifying length for cutting to size using a pipe cutter.

Here is a close up with the sleeve and the cover holding the pipe in place.

Once the pipe was cut to size... then started on the trouser assemblies (these were done earlier this year) after they were printed... waiting till this moment.

Here are the trousers with their respective bearings and couplers that fit around the pipe.  The issue is that the pipe James used was 25mm, in the states its 1/4" which is slightly smaller...

Here is a great shot of the assembly hanging from the pipe... so far so good

Close up of the trousers and its bearings.

Drive System Part 3: The Banana - Drive harness work

Wrong guesstimates...

I had purchased M6 bolts for the wheels to keep the banana stable inside the main hub (cheese).
The measurements are off... by 10mm.

Here are the new parts from amazon:

We will need 2 of these M6 X 130mm:
https://www.amazon.com/gp/product/B00LCGIXDW/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

NOTE: This is for the long bar that connects the inner small wheels to the main drive assembly. 

We will need 6 of these M6 X 30mm:
https://www.amazon.com/gp/product/B018RSVUSC/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

NOTE: While the 6 are for the outer wheels that push against the hub.

Here are some photos of the pieces being assembled:

These are the outer connections that will hold the wheels that "push" against the walls of the hub as the main drive chassis (banana) rolls freely inside the hub (cheese).

I place the piece into the vice and then screw the banana pieces into it... the placement is as follows:

The screws are #4-40 1/2" screws and each piece needs 2 each.

Here is a photo of a completed side... notice the placement of the guides or mounts.

The completed the banana frame... the measurements for the M6 bolts were off by 10mm so I have ordered new pieces:

Qty	Part Type and Name	Cost	Where
6	M6 40mm bolts https://www.amazon.com/gp/product/B018RSVUSC/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1	8.00	Small outer wheels on banana
2	M6 130mm bolts https://www.amazon.com/gp/product/B00LCGIXDW/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1	7.39	Small inner wheels on banana

Given the custom sizes... they will not arrive till first week of Sept.

The wheels were not 3D printed... I purchased these instead which matched the size of the 3D printed wheels.

20	Luggage Wheels (50mm x 18mm x M6) https://www.amazon.com/gp/product/B014P2B5GQ/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A1GN9TQ2EDBVOI

Drive System Part 2: The banana - Drive harness

Drive System Part 2

After completing the gluing and waiting for it to dry (days)

NOTE: the glue that was used: Weld-on 16 which dries not as fast and allows time to set the parts.

https://www.amazon.com/gp/product/B00MBP2VAO/ref=ox_sc_act_title_6?ie=UTF8&psc=1&smid=A1QO0V8LDU7BFX

The drive is simply an auto windshield wiper motor... after watching James' video several dozen times I picked this one which resembled it best...

https://www.amazon.com/gp/product/B00TIDDJWG/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=AX96KWIRXDDJ7

The drive itself fit the harness and although didn't match the color schema of James' I had my father who is a electrical engineer figure out which wires were the hot wires.


I started by fastening the center harness... but backed it out when I determined the only way to connect the outer wheel connectors was with it off...