Cycloidal Gearbox Manufacturing & Assembly

Note, all files referenced in this document live within ~\Laika-CAD\DRIVE TRAIN\CYCLOIDAL DRIVE. For specific files, their location within this folder can be figured out by looking at the prefixes in their filenames.

1) Laser-cutting

Delrin was selected as the material of choice for this sub-assembly due to its low coefficient of friction with itself and steel. The thickness of the Delrin sheets used for the manufacture of this design is 3/16". This project specifically bought out Delrin from {McMaster-Carr|link}.

Large sheets of plastic are prone to warping, and in the case of this, the following two sections can be optionally followed.

1.0.a) Cutting Delrin into squares

Delrin sheets ordered from McMaster-Carr tend to be warped, so in order to alleviate the issues this may cause, cut the Delrin into {dimension} squares. This can be done with a band saw or laser-cutter.

1.0.b) Flattening Delrin squares with a hot plate

The previously cut Delrin squares can be flattened using a hot plate. We specifically used a {Name and number of the hot plate used | link}. The heated plate is larger than the {dimension} Delrin Squares, and can heat to {glass transition temperature of Delrin}, the glass transition temperature of Delrin.

1. Place the Delrin Sheet onto the hot plate.
2. Place a flat, heavy object on top of the Delrin sheet.
3. Heat the hot plate to the glass transition temperature of Delrin, which is {temperature}.
4. Let the Delrin sheet sit for an hour with the heat turned on.
5. Turn off the heated plate and let the sheet sit for another hour

[This process needs to be tested more regarding what temperature the heat plate should be set to, and how long to keep weight on it]

1.1) Laser-cutting parts

Out of the Delrin Sheets, laser-cut the following files, take note of the quantities required:

• CYC 002 - Main Body 2.DXF x3
• CYC 003 - Top Lid 1.DXF x2
• CYC 004 - Top Lid 2.DXF x1
• CYC 005 - Eccentric Gear.DXF x1
• CYC 006 - Top Hat 1.DXF x1
• CYC 006 - Top Hat 2.DXF x1

CYC 001 is not meant to be cut, it was left out purposefully.

2) 3D Printing

The following part needs to be printed on an FDM 3D printer: a) CYC 011 - topHatThin.SLDPRT x1

{should be renamed and also should be as a .step or .3mf or .stl}

3) Milling

Only one part in this assembly needs to made on a mill, which is a sub-part of the main body part.

3.1) Milling screw holes

3.2) Milling bearing hole

3.3) Milling ball-bearing divots

3.4) Milling slots {is that the word to use???} for wall pins

4) Lathe

4.1) Wall Pins

4.1) Load Pins

4.2) Tapping Wall Pins

5) Assembling sub-parts

This section provides instructions on how to assemble each part, as it is in the Solidworks assembly, out of its constituent parts.

5.1) Main Body

For this, the following parts are needed:

• 1x CYC 001 - Main Body
• 3x CYC 002 - Main Body 2

[Photo here]

The parts can be aligned using the unfilled slots for the wall pins. Once this is done, put long m3 screws through the screw holes, but do not attach a nut, to align the parts further.

[Photo here]

Apply superglue generously between each of the parts, and then clamp the assembly in place, taking out the screws and making sure that the slots for the wall pins are aligned.

[Photo here]

Wait 5 minutes, and this part should be done.

[Photo here, solid-works screenshot won't work because needs to be shown with stupid square, as in pre sanded.]

5.2) Top Lid

For this, the following parts are needed:

• 2x CYC 003 - Top Lid 1
• 1x CYC 004 - Top Lid 2

Place the parts like this: [photo]

Follow the same steps as in 5.1 for aligning the parts and gluing them together. [photo]

5.3) Belt-sanding Main Body and Top Lid

Because the laser cutter might be operating beneath our upmost expectations, the outer walls of the laser cut parts may be strangely sloped. This may result in a non perfectly cylindrical outer wall of the gearbox.

More notably, the bottom portion of the Main Body is a square, which is a greater impediment to a spherical gearbox.

Use a band saw to cut away the bulk of the square corners of the Main Body to get it as close to a circle as possible. [photo]

Then, take the Main Body and Top Lid parts just made, and screw them together tightly using {screw dimensions} and nuts. [photo]

After this, use a belt-sander to get the assembly as close to a cylinder as possible. [photo]

5.4) Top Hat

For this, the following parts are needed:

• 1x CYC 006 - Top Hat 1
• 1x CYC 006 - Top Hat 2

{The 3d printed part is not here, because it honestly does not need to be glued on because the load pins will hold it anyways}

6) Assembly

This section provides instructions on how to assemble the entire gearbox out of the assembled sub-parts.