Summary

I designed this spinner for my 6 year old son since the standard configuration of 4 608ZZ bearings is too big for his hands. The outer bearings are now 625Z bearings with a diameter of 16mm instead of 22mm.

To be clear, the center is still a 608 bearing as I've found that the smaller bearings don't spin nearly as well in this size of object.

I recommend using the knobs designed by CPME listed here:
https://www.thingiverse.com/thing:1979370

Print Settings

Printer Brand:

Wanhao

                                            <p class="detail-setting printer"><strong>Printer: </strong>                     <div><p>Wanhao Duplicator i3 V2</p></div></p>                                                                                <p class="detail-setting rafts"><strong>Rafts: </strong>                     <div><p>No</p></div></p>                                                                                <p class="detail-setting supports"><strong>Supports: </strong>                     <div><p>No</p></div></p>                                                                                <p class="detail-setting resolution"><strong>Resolution: </strong>                     <div><p>0.3</p></div></p>                                                                                <p class="detail-setting infill"><strong>Infill: </strong>                     <div><p>10%</p></div></p>                                                        <br>                        <p class="detail-setting notes"><strong>Notes: </strong>                    </p><div><p>These pop off at about 15 minutes apiece with my current settings, so you can hammer out 4 in an hour, easy.</p></div>

Post-Printing

Hammers work, but I've been using channel lock pliers to squeeze the bearings in along the edge of a picnic table: one side of the pliers under the tabletop, one over the bearing.

How I Designed This

I used Fusion 360. Simple circular array with a little bit of filleting.

Small Hands Spinner (625Z)