Tool to Help Scale Model Size

thingiverse

If you routinely adjust the size of models to dimensions of your choice, there probably isn't anything here that you don't already know. The purpose of the printed tool, or a piece of paper with a line of known dimension drawn on it, is to adjust the scale of a 3D rendered image to a known size that you can measure with a caliper or compare to a real object for size comparison. It is important to adjust the display so that it is the parallel projection mode. It may be named something else, but you want to avoid the mode that displays the model in perspective (the grid lines will be closer together at the back edge of the XY display plane). When making measurements from the display, the surface measured should be parallel to the front edge of the screen. You can't make measurements on an isometric view of any surface other than that parallel to the edge of the screen. For small angles though, you can be off-square (as one of the photos is) and it won't make much difference since this scheme does not have high accuracy at any stage beyond the original CAD drawing. I typically use this to adjust the scale of a model displayed in Repetier Host (or Cura, or Sketchup or other) so the model is displayed at its actual real-life size. When the scale of the display is accurate, you can make measurements on the display of the model to determine its printed size. In the case of a cup or other vessel, you can section the model, measure it's interior dimensions, and calculate the volume. The tool here is 40 and 50 mm on the outer edges. The interior edges are 20 and 30 mm. The outside long-dimension is 60 mm, and the width of the parallel ends is 10 mm. The photos are of the parallel projection display in Repetier Host. They show a whole model and a sectioned model with the display adjusted to match the 4 mm side. The resulting model is then life-size (on the display screen), as long as you don't do anything to cause the display program to zoom to fit the screen.