Pre-K kids counting toy

Over 60 years ago my dad built a kids counting toy out of wood:

This toy recently came back into my possession and one of the number tile pieces was damaged. Using Fusion 360, I was able to recreate the tile and a co-worker loaned me some Hatchbox wooden filament and it resulted in a pretty good replacement piece.

Recently I started dabbling with OpenSCAD and I thought it might be a good exercise to see if I could recreate this toy in OpenSCAD.  Spoiler alert, I was successful. 

I have included the SLTs required to print this toy as well as the OpenSCAD file used to generate it. When importing the post, please make sure that a flat side is touching the bed and the post STL included for download should import correctly.  Early in development, there were times when the OpenSCAD exported post STL file would import into Prusa Slicer on an edge. 

Note: for safety reasons, I super-glued the posts to the base.

So far I have printed all my counting toys in PLA using 0.2mm and all the standard defaults. On my Prusa MK4S, the base for the 1 and 2 take just over an hour to print, the base for the 3 and 4 takes about 1 hour and 50 minutes, and the base for the 5 and 6 takes just over two hours to print. A single tile takes about 21 minutes to print.  Printing 7 posts takes about 46 minutes.

The OpenSCAD model by default will generate the main board with mounting post holes, one of every tile, and one mounting post.

I am leaving it up to the user to configure how they want to print the model parts.  The main board was designed to be printed with the holes facing the build plate.  This will provide the best surface finished surface for the top of the counting toy.  The post should be printed as shown in the picture above and make sure one of the flat sides of the post is pinned to the build plate.

The base is too large be printed on most printers. I printed my board in three seperate segments with Prusa Slicer's dovetail cutting capabilities (using the defaults settings). To aid in laying out the dovetail cut line, I have provided a small cutlines on back of the base (too small for the slicer to do anything with). The worked perfectly for me.

You will have also noticed that the posts are octagonal instead of round. I did this for two reasons: 1) they can horizontally on the bed for faster printing, 2) it allowed the post mounting holes be printed upside down.

Regarding the OpenSCAD file. My original goal was to design this model so that it could be scaled by a single input value.  While this mostly worked, it ended up being a bit frivolous as scaling can be more easily done on modern day slicers. The functionality is there (well at about 95%, I think there is one spot where the scaling does not work well), it is best if you run with the default parameters.  As a user, you can adjust the parameters anyway you want, but I cannot guarantee you will get the results you were intending.  Here are the exposed parameters that can be adjusted.  I am thinking the GENERATE [TILES | BASE | POST] are the ones that will be modified most.

If you find this item useful, please consider making a donation of any amount the Phelan McDermid Syndrome Foundation (PMSF) under AudienceOfOne:

• https://donate.pmsf.org

Thanks, AudienceOfOne