We aren’t associated with OnShape in any way, but it is a pretty neat online CAD program AND it’s free! We have been making a CAD model of the basic M1078 chassis so that we can design our camper hab to integrate nicely with the truck. We thought we would share the CAD model so that it can be helpful to others in their expedition truck designs.
The CAD model is fairly accurate for our intended use. The truck bed rails and interface areas are probably accurate within 1/8-inch. We included some more aesthetic features like tires, bumpers, and cab to help us visualize how our hab integrates with the overall truck. However, some of these features are less accurate in the CAD model and likely vary from truck to truck, anyway.
This is what is considered a de-featured model in engineering. Many truck components are intentionally omitted to keep the model simple and easy to work with.
Anyway, we hope the model is useful to others, but if you do use it, take it with a grain of salt. If you do use the model, you may find discrepancies between your truck and the model. We do not intend to update this model, so it should just be a stand alone file that people can access for reference in the future.
To use the model, go to OnShape and set up a free user account. Go to the search bar on the website and search for M1078. The search should show the model that we have made public. You won’t be able to find the model unless you make an account and are logged in. The model is pretty big, so it will take a few minutes to open. Once it is open, you can model your own habitat, roof racks, and accessories on OnShape, or you can export the model and open it in a program that you may have at home.