Summary

For a better feeling when you play chess, I added weight to all pieces.
This is done with an M5 steel flat knurled nut (common one DxT = 16x5 mm) inserted at the bottom of each piece.
I tried to keep the standard size of each. Printing parameters are kept the same than original.

Print Settings

Printer Brand:

Anycubic

                                            <p class="detail-setting printer"><strong>Printer: </strong>                     <div><p>Kobra</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>.15</p></div></p>                                                                                <p class="detail-setting infill"><strong>Infill: </strong>                     <div><p>30</p></div></p>                                                    <strong>Filament:</strong> CReality CR-PLA                Ivory

How I Designed This

I used Freecad to design the base
Then cut a little the bottom of original to achieve a similar height minus base size
Last, I merged with the base

Organic Chess Set with weight