The three little One Track Mine Co. machines are so much fun I decided to build them first as some sample models. As I designed the routing reliefs I made some modifications to make them better. I’m sure more modifications will follow as we build the pieces full size as well.
I built the vector files completely in EnRoute. The track files are a lot like the tank files we built a little while ago but these sport a little more detail. The biggest change from the concept sketch was the addition of a motor hood. I built it in three sections (two sides and a front)
I started with the track backing plate. This was created as a relief 0.2″ thick. The center was then dropped by half that to effectively create the chain links between the treads.
The cleat sprockets were next and were created as separate reliefs 0.3″ tall. I then selected the track pieces and combined them with the track shape. I could do this because they protruded outside of the track shape. The sprocket pieces were MERGED HIGHEST with the track back.
The center springs were created by modifying the track background relief.
The wheels were next and were created as separate reliefs. These were then MERGED HIGHEST with the track back.
Next the wheels were dished down by modifying the base relief using the subtract and dome tool.
And the wheel lugs were then added by modifying the base relief and using the ADD TO and dome tool.
The top portion of the track support was created as a separate relief and then merged highest with the track relief.
Last up for the track reliefs were the cleats. These were created as separate reliefs that were one inch tall. Since they were outside but overlapped the base relief I selected the cleats and the base relief and then used the combine tool to make them one relief.
The floor and hood of the little tractor was created as a separate flat relief. that was 1.2″ tall. The hood vent slots were then dropped into this relief using the subtract tool. This new piece and the track relief were then selected and combined into one relief.
The grill of the tractor was next. I first created a zero height relief.
I then used the chamfer tool to round off the front edges uniformly all the way around.
The grill and started holes were then created using the subtract tool.
I then created a zero height relief and used the merged highest command to effectively clip the bottom off the grill. I then used the slice tool to take off the zero height portion of the relief.
I then modified the track relief by adding the little circle to the base bracket. This will be used to mount all of the accessories to the tractor.
The last step was to create a dirt base for the tractor This was done as a simple flat relief which was 1.5″ tall. This new separate relief and the tractor relief were selected and combined to form one relief.
The track relief was duplicated and flipped so I could glue it to the back of the original to create the tractor. The grill will be glued to the end of the motor housing. The piece was now ready to be tool pathed and sent off tp the MultiCam. It will be routed from a piece of 1.5: 30 lb Precision Board. Stay tuned for the next steps…
Published with permission from precisionboard.blogspot.com. Source.