3D Printing,  Model Building

Construction Tools

Not everything is a nail

Tools come in all shapes and sizes and purposes. If you are outside of a given field of knowledge, you might not realize just how specialized some tools can be. For example, until I took those blacksmithing classes, I never could have imagined the number of tongs and hammers that existed. And this limited belief existed even when I had previously taken some blacksmithing classes (the skill and background of an instructor is really important).

When I start something new, too often I fall into the trap of thinking everything is a nail and I just need to find something to bludgeon it into place. For example, I needed long strips of 5mm x 5mm EVA foam cut on a diagonal. These are to go under the interior stairs to offer support. My first attempt involved using the utility knife and a ruler to cut the strips by hand. Which I then tied to turn on its side and slice into a pair of triangle shaped pieces.

As you can imagine, that did not work well. I knew I needed better tools. So I printed the small block that had one edge that was a 5mm x 5mm corner and the other side, a channel with 5mm x 5mm opening on the diagonal. I cut my foam pieces to length, then used my fingers to tension the piece as I sliced it in half. This tool failed on three fronts:

  1. It was too short and when I cut the long strips, it left marks every time I repositioned it to resume cutting
  2. My finger pressure when cutting on the diagonal could not remain consistent enough to hold the piece in place to get a straight cut
  3. The utility knife is sharp and flesh is weak

Why I love 3D printing

The 3rd issue prompted version 2 of my tool. Until that point, I still wanted to bludgeon things into place. So I jumped back on FreeCAD and designed a couple more tools. The more I play with the software, the faster I get at putting things together. And my Prusa printer kicks out the 3D models quickly enough that I can remain productive.

I fixed issue 2 and 3 by making a pair of interlocking pieces that included space for a channel for the utility knife. No more cutting off part of my finger and the pressure on the top and bottom of the EVA foam remained consistent because it could not move in the channel. I also printed up a long tool so that I could get straight cuts without having to reposition the jig multiple times. The long jig I later printed with various sized edges so I could also make the stair steps in an easier and more consistent way.

Tools for support

Some of the tools I created for the tower are just for support. The stairs and the large circle are there to remain in the tower’s structure. The circle piece I will use for each floor as a flat base in the outer wall. The stair support I designed in FreeCAD to allow for variable depth, width, and height of the stairs. Each floor could end up with a slightly different number of steps and I found printing the part much easier than cutting pink foam by hand (which I did for the outside stairs). I’ll talk more about that in a separate post.

The odd rounded shape I used to build the entry into the tower. I needed something to act as a support structure while I place foam blocks over it to create an arch. This is not dissimilar to arched stone passages are made at full sale, only in real life, the tools used might be wooden supports that are later removed.