[Coley]

In my work I often design parts in 3D-Solidworks and to a lesser degree Autocad pretty much all the time for work/design/engineering purposes.
I have always considered measuring up and making a few interesting parts from the truck realm....but as of yet I haven't applied any time to it.
In reality it would probably take less than an hour to accurately measure up a part then about the same to commit to 3D design...some more, some less...depending on the part.
That said, I have had designed parts made up in 3D in the past and it looks like the resins are getting better. That last part I had made up a couple of years ago was very accurate...but very brittle and not much use other than as a 'display model'.
As was stated...when the model is complete it can be exported/saved as an .stl file which plugs right into the format for these printers.
Here are a couple of quick jpegs of what I have designed in that past...at least in plastics, noting that most of my design/engineering work is rooted in mechanical/equipment/automation components....ie: metal. Regardless, this part was way more complicated than anything we would find in these trucks...so the difficulty level is pretty 'doable'.

All Good
Coley