Summary

These are all of the threads I have a knob for:

US Threads:
1/2 - 13
1/2 - 20
3/8 - 16
3/8 - 24
7/16 - 20
7/16 - 32

Metric Threads:
M8 x 1.25
M10 x 1.25
M10 x 1.50
M12 x 1.25
M12 x 1.75
M16 x 1.50
M16 x 1.75

Print Settings

Printer:

Prusa I3

                                            <p class="detail-setting rafts"><strong>Rafts: </strong>                     <div><p>Doesn't Matter</p></div></p>                                                                                <p class="detail-setting supports"><strong>Supports: </strong>                     <div><p>Doesn't Matter</p></div></p>                                                                                <p class="detail-setting resolution"><strong>Resolution: </strong>                     <div><p>0.2mm</p></div></p>                                                                                <p class="detail-setting infill"><strong>Infill: </strong>                     <div><p>50% - 100%</p></div></p>                                                        <br>                        <p class="detail-setting notes"><strong>Notes: </strong>                    </p><div><p>100% infill is recommended if you're going to use it daily. If you print with supports, make sure they do not touch the threads, as they are a pain to remove and are unnecessary.</p></div>

Post-Printing

Painting

            <div><p>Use a paint or clear coat that will hold up to rigorous use.</p></div>

Marshmello Shift Knob