Summary

Test M42 thread (bolt and nut)
Inside hole fits for 1.25 eyepiece format.

Add T2 version.

Print Settings

Printer Brand:

Monoprice

                                            <p class="detail-setting printer"><strong>Printer: </strong>                     <div><p>Select Mini</p></div></p>                                                                                <p class="detail-setting rafts"><strong>Rafts: </strong>                     <div><p>Yes</p></div></p>                                                                                <p class="detail-setting supports"><strong>Supports: </strong>                     <div><p>Yes</p></div></p>                                                                                <p class="detail-setting resolution"><strong>Resolution: </strong>                     <div><p>0.22</p></div></p>                                                                                <p class="detail-setting infill"><strong>Infill: </strong>                     <div><p>Progressive</p></div></p>                                                    <strong>Filament:</strong> nc PLA

Post-Printing

Remove supports and rafts.
Threads doesn't fit well first time. You need to force a little. After threads fits very well.

M42 thread test + T2 (Openscad)