Ravitz Chess

Home page for Ravitz Chess

Notes | Stacking Chess Pieces

Weighted | Resin | FDM | Old Files | Storage Tube


Notes

This page is for distribution of my chess pieces via 3D print file (STL). The files are free for printing for personal use.

contact - caryravitz_at_gmail.com (replace _at_ with @)

www.ravitz.us

Last modified 9:45 PM, 24 Feb 2024 - File size 12K - Count 4554
 
 

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Stacking / Nesting Chess Pieces

These chess pieces were designed by Cary Ravitz, 2021, 2022. The pieces stack in any order. Stacking on top of the king or queen takes extra space.

I am currently publishing only STL 3D print files (generated by OpenSCAD from a SCAD file). There are designs optimized for resin printers and FDM (thermoplastic filament) printers. No supports are needed - horizontal overhangs max .5mm, angled overhangs minimum of 45 degrees, no bridges. The ZIP files include STL files with just the models and the models with my rafts.

Since I took these photos, I have revised the pieces a bit.

stacking chess pieces stacking chess pieces stacking chess pieces

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Weighted Resin Pieces (3.75 inch king)

stacking chess pieces

resin, weighted, zip file - 2024-02-18 These are slightly revised and includes a king with integrated cross.

The Pieces

These new pieces are taller, 3+3/4 inch king, weighted with .5 to .75 ounce weights, and have slightly revised styling.

The king's cross is a separate piece that screws in. This takes about 15% off the height which is a significant amount of printing time. The model has six crosses, each with a different screw angle (5 degree steps). Choose the one that gives the best alignment.

You need to print a cap for each piece. This screws into the base to contain the weights. It can be hard to unscrew once it is tightened, so don't tighten it until the weights are in place.

The model is oversize by .9% to account for cure shrinkage.

The four point star cutouts and holes at the bottom of the weight cavities are there to drain uncured resin and allow alchohol to flow through the interior.

I use Uniformation plant based white and black, and Siraya Tenacious clear. White pieces - 75% white, 5% black, 20% clear. Black pieces - 5% white, 75% black, 20% clear. I think that the resulting light gray and dark gray shows the pieces better than black and white.

The Weights

You have to print a cap for each piece, fill the cavities, and screw on the cap.

The weights are implemented with weight cavities in a band around the base. You will have to fill the cavities. They take 30 steel dowel pins 3mm x 12mm (look for M3 dowel pin on ebay), which is .7 ounce per piece. You need 960 to completely fill a 32 piece set. Compare prices carefully on the dowel pins. I have found them as low as $50 for 1000 on ebay.

Or they can take #6 spherical shot. Ballistic Products has SpheroTungsten Original-15, .73 ounce per piece, $85 for 2 pounds. And SpheroTungsten Super Max-18, .87 ounce, $107 for 2 pounds.

I have used Lawrence #6 copper plated lead shot, .55 ounce per piece, $60 for 10 pounds on Amazon. I won't use unplated lead because I don't want to handle it.

You could also cut your own 3mm x 12mm rods of brass or steel. BUT that's 960 pieces. Even 10 at a time in a chop saw would be 96 cuts. And you need burr free pieces, which I could not get from brass (I haven't tried steel).

The Rafts

My rafts were developed to be easy to remove by hand (with glove). This reduces the uncured resin that gets into the wash.

I use a flex plate. The rafts come off easily by hand when the plate is flexed. I remove the rafts, use a prewash bucket of alcohol, and wipe the excess resin by hand. Then on to the automatic alcohol wash.

For the cross, leave the raft on until curing so that it doesn't fall through the washing basket.

full size full size

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Resin Pieces (3.75, 2.25 inch king)

full size

resin, large, zip file - 2024-02-18 - For the separate king's cross version, the cross is printed separately as six crosses - choose the one that aligns best. This saves a lot of print time.

resin, large, separate base, zip file - 2024-02-20 - These print the top and base separately, letting you choose different resins for each. I have not tested the top rafts on these.

resin, small, zip file - 2024-02-18 - These have an increased diameter, so they don't fit the old tube (1 inch inner diameter is needed).

full size full size

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FDM Pieces (3.75, 2.25 inch king)

stacking chess pieces

fdm, large, zip file - 2024-02-20

fdm, large, separate base, zip file - 2024-02-21

fdm, small, zip file - 2024-02-20

I find working with resin to be a very unpleasant job. It stinks, it's hard to clean up, it requires protective equipment, nasty chemicals, and when you finally have good models, it's not clear how long they will last due to UV aging. So I modified the design to aim at FDM printers. FDM cannot handle the detail needed for the weights or screw threads. The drain hole stars are repurposed to hide seams.

The small models do not fit the old small storage tube. 1 inch inner diameter is needed.

The separate base models lets a you print black and white tops and combine them with metal filled plastic (heavy) or different color bases. Depending on the overprint, the fit might be tight or it might need a bit of glue. I have not tried the metal filled filament - watch out for metal content and density, and get an appropriate nozzle.

Setup (mostly default) -
Creality Ender 3 V3 KE
.4 mm nozzle
Hyper PLA (that's Creality's high speed PLA)
.2 mm layers. .3 mm first layer
no brim, no supports
15 perimeters, that gives 100% solid with no "infill"
seam position aligned
perimeter generator classic
perimeters 200 mm/s
small perimeters 100 mm/s
nozzle 205, build plate 60

A knight takes 34 minutes to print. The result is not bad. The pieces stack nicely and look decent - much better than my old Lulzbot Mini. It appears that FDM printers have improved quite a bit since my first printer.

stacking chess pieces

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Old Files

weighted, with raft, zip file
weighted, zip file
large, with raft, zip file
large, zip file
small, with raft, zip file
small, zip file
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Storage Tube

endcaps

endcap for tube outer diameters 1.125 inch, zip file
endcap for tube outer diameters 1.250 inch, zip file
endcap for tube outer diameters 1.600 inch, zip file
endcap for tube outer diameters 1.750 inch, zip file

These are designed for FDM printers and do not need any support or rafts. I suggest .1 mm layers to get smooth screw threads. The extra cuts in the threads let the slicer minimize seams - this is important to make the caps work well.

Inner diameters are 1 inch for the small models and 1.5 for the larger models. You can scale in the slicer to accommodate variations in tube outer diameter and model inner diameter.

When storing the chess pieces, stack them with a bishop on top of the king and a pawn on top of that bishop - this minimizes the total stack height.

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