Wombat: Modular Truck Concept

The idea was to create a capable consumer vehicle that offers a unique level of customization to buyers. The design started with a very minimal 2-seater, open-top truck body and ideas were digitally sketched before it was created in CAD. This concept is a modular truck that allows for easily swapped-out parts such as the front bumper, wheel fenders, seats, rollbars, and even a whole cabin. The main philosophy behind this design is the prioritization of functionality, adaptability, and personalization. Trucks are known to be durable and reliable machines, this concept reflects those strengths and builds upon them through its modular capabilities.

Hence the name "Wombat," which are highly versatile and adaptable mammals known for being muscular and "built like tanks." The Wombat modular truck concept may appear unassuming, but just like the Australian marsupial, adaptability is its biggest strength. Buyers can configure their very own vehicle for daily-driving and weekend off-road adventures. Since this truck reduces limitations of purpose and function, it can be used by anyone, anywhere. It's a feasible concept that relies on existing and proven technologies for its production such as powertrains (engines) and suspension. At least that would be the ideal situation if this were to fully launch as a car model.

I do apologize in advance for the nearly 90 steps for this project. It's well worth it and feel free to modify/add parts of your own, have fun!

1. Autodesk Inventor or similar application: used for all CAD files -> made in 1:1 scale in inches
2. 3D Printer: Elegoo Centauri Carbon (for all parts printed)
3. Sandpaper or file -> if parts need better fitment after print
4. Tamiya Spray-paints: white (headlights), red (taillights)
5. Masking Tape -> if model is to be painted
6. Gorilla Superglue -> suggest using clamps or tape to keep parts together
7. SCX24 Rims and Tires -> RC car tires used for 1:17 scale model, proportional to 34" tires on a 1:1 scale (optional part; not necessary)

1. Start sketch with 3” circle constrained to origin
2. Total “wheelbase” (distance between the two circles) is 100”
3. Suggest sketching a few lines at a time then placing dimensions
4. The “hood” part above the left side circle is an arc with a tangent constraint with the “beltline” (the 55” line on the top-mid section) → vertical distance between the two arc points is 3”
5. This will be the silhouette of the body

1. Extrusion made based on Sketch 1
2. Extrude Sketch 1 60” as shown
3. This will be the width of the body

1. Use fillet tool on the bottom-mid edges after Extrusion 1
2. Fillet the edges 5”
3. This will be the “belly” of the truck

1. Use fillet tool on the top edges of truck → extends from the “front” towards the rear before the “wall”
2. Fillet the edges 3”

1. Use fillet tool on the top-rear edges of truck
2. Fillet the edges 3”
3. Can be combined with Fillet 2

1. Start Sketch 2 on the horizontal plane on the top-center of the body
2. Suggest projecting geometry + slicing graphics
3. This will outline the “cockpit” of the truck

1. Extrusion made based on Sketch 2
2. Extrude as a subtraction of material with a combined 39” in as shown from Sketch 2
3. This will be the “cockpit” section of the truck

1. Use fillet tool on inner edges of the “cockpit”
2. Fillet the edges 1”
3. This will round off the interior edges of the “cockpit”

1. Create an offset plane 34.5” above the horizontal origin plane (the plane that should intersect both circles)
2. Start Sketch 3 on top of the new plane → Sketch 3 should be located directly behind the “cockpit”
3. I suggest splicing graphics or projecting geometry to assist in lining up Sketch 3 behind the “cockpit”
4. This will be the outline for the “trunk” or “bed” of the truck

1. Extrusion made based on Sketch 3
2. Extrude as a subtraction of material with a combined 44” in as shown from Sketch 3
3. This will be the “trunk” or “bed” space of the truck

1. Use fillet tool on the front corners of the truck as shown
2. Fillet the edges 1”

1. Use fillet tool on the corners of the “seat wall” behind the “cockpit”
2. Fillet the edges 3”

1. Use fillet tool on outer-bottom edges under the truck
2. Fillet the edges 2”

1. Start a new sketch and create Sketch 4 on the back of the truck
2. Create the geometry shown on the left side
3. Create a construction line in the middle to mirror the geometry
4. I suggest projecting geometry + horizontal/vertical constraints

1. Extrusion made based on Sketch 4
2. Extrude 1” out
3. These will be the “taillights” of the truck

1. Start a new sketch and create Sketch 5 on the top of the truck (select a flat surface to start the sketch on)
2. Create the geometry shown, do not close the sketch
3. Use a construction line in the middle to mirror the geometry
4. This will create partition lines to assist in the 3D printing process

1. Select the object (in this case the whole truck body)
2. Select the geometry shown to create the split

1. Select the object (the object highlighted yellow)
2. Select the geometry shown to create the split
3. This will result in 3 separate objects

This completes the Wombat body.

For Printing: create the body splits → print in 3 separate parts to ensure print quality, suggest printing the two side parts on the flat face

1. Start Sketch 1 with the large middle rectangle section → constrain midpoint of line to the origin
2. The small rectangle within the large rectangle will be the “grill” section of the bumper
3. On the right side, sketch the large trapezoidal shape (this section houses the “headlight”)
4. Within the trapezoid, sketch another, smaller trapezoid that extends slightly forward
5. This small trapezoid is 6” wide and 6” long on the inner edge → will be the “headlight” part of the bumper
6. Place construction line through the middle
7. Use construction line as a mirror line for the geometry on the right side → complete the left side of bumper
8. I suggest using parallel and vertical constraints

1. Suggest rotating sketch 90 degrees clockwise
2. Create another trapezoidal shape extending behind the “headlight”
3. Use the same construction line from Sketch 1: Part 1 to mirror geometry
4. This is a top-down view of the bumper

1. Extrusion made based on Sketch 1
2. Extrude Sketch 1 7.85” as shown
3. There will be gaps left for the “grill” and “headlight” sections
4. This will be the height of the bumper

1. Extrusion made based on the “headlight” sections from Sketch 1
2. Extrude 7.85” as shown in order to fill the gap
3. Can be combined with Extrusion 1

1. Extrusion made based on the top of the “headlight” sections from Sketch 1
2. Extrude 1” as shown
3. This will be the height of the “headlight”

1. Extrusion made based on the front of the “headlight” sections from Sketch 1
2. Extrude 6” as shown based on the extended “headlight” portion

1. Extrusion made based on the same geometry as Extrusion 4
2. Extrude 1” as shown to complete the “headlight” fixture of the bumper

1. Create an offset plane on the “grill” section of the bumper
2. The plane with be flush with the inner part as shown
3. Start a Sketch 2 on this plane → create a rectangle that extends the width of the “grill” with a 1.85” height
4. I suggest slicing graphics and/or projecting geometry to assist

1. Extrude based on Sketch 2
2. Extrude 1.3” as shown

1. Use fillet tool on the bottom-mid edges of “headlights”
2. Fillet the edges 2”

1. Use fillet tool on the top-forward edges of “headlights”
2. Fillet the edges 1”
3. Can be combined with Fillet 1

1. Use fillet tool on the top edges surrounding the bumper as shown
2. Fillet the edges 0.6”

1. Create a new plane on the right side of the bumper
2. The plane will be flush with the flat side as shown
3. Start Sketch 3 → create a triangle on the lower right side as shown
4. I suggest projecting geometry + using dimension tool to constrain

1. Extrude based on Sketch 3
2. Extrude as a subtraction of material 70” as shown → this will make the extrusion even on both sides

1. Use fillet tool on the 4 bottom edges of the bumper as shown
2. Fillet the edges 3”
3. This will round off the bottom sides of the bumper

This completes the Front Bumper.

For Printing: can be printed straight up, may need supports depending on printer

1. Create sketch shown
2. This will be a top-down view of the “dashboard”
3. I suggest constraining mid-point of the bottom line to the origin

1. Create extrusion based on Sketch 1
2. Extrude 19.25” as shown

1. Create Sketch 2 on the left side-view of the “dashboard”
2. I suggest projecting geometry to assist
3. Ensure sketch is created as shown with the curved part of the “dashboard” facing the left

1. Create extrusion based on Sketch 2
2. Extrude 50” as shown as a subtraction of material

1. Create Sketch 3 on the front of the “dashboard”
2. This will outline the “heads up display”/”gauge-cluster”

1. Create extrusion based on Sketch 3
2. Extrude 4.5” as shown as a subtraction of material
3. This space is where the “heads up display”/”gauge-cluster” will be

1. Create Sketch 4 on the front of the “dashboard”
2. I suggest constraining Sketch 4 to the top-mid point
3. This will outline the “center console”

1. Create extrusion based on Sketch 4
2. Extrude 15” as shown

1. Share Sketch 4 to create extrusion
2. Extrude 15” as shown
3. This will be the “center console”

1. Fillet edges shown under the “dashboard”
2. Fillet 2” as shown

1. Fillet edge shown under at the end of the “center console”
2. Fillet 7” as shown

1. Start Sketch 5 on the left side of the “dashboard”
2. I suggest projecting geometry
3. This will be the top portion of the “center console”

1. Create extrusion based on Sketch 5
2. Extrude 6.5” as shown

1. Fillet edge shown on the sides of the “center console”
2. Fillet 1”

1. Fillet edge shown on the top of the “dashboard”
2. Fillet 0.4”

This completes the Dashboard.

For Printing: can be printed straight up, supports will be needed on the underside and won’t be visible once broken off

1. Create sketch shown
2. I suggest constraining bottom left corner to origin
3. This will outline the side vertical support

1. Extrude based on Sketch 1
2. Extrude 3” as shown
3. This will be the left side vertical support for the “rollbar”

1. Create sketch shown on the backside of Extrusion 1
2. The arc shown is 0.813"
3. Suggest using horizontal constraints

1. Extrude based on Sketch 2
2. Extrude 46.5” as shown
3. This will be the horizontal support

1. Start Sketch 3 on the end of Extrusion 2
2. Refer to the following Step for clarification
3. This will be a mirror of the geometry shown in Sketch 1

1. Extrude based on Sketch 3
2. Extrude 3” as shown
3. This will be the right side vertical support

1. Fillet the top corners of the “rollbar” as shown
2. Fillet edges 2” as shown

1. Fillet inner edges on vertical supports shown
2. Fillet edges 1.5” as shown

1. Start Sketch 4 on the outer face of Extrusion 1
2. Create the geometry shown
3. I suggest projecting geometry

1. Extrude based on Sketch 4
2. Extrude as a subtraction of material 0.25"

1. Start Sketch 5 on the outer face of the right side vertical support
2. Create the geometry shown
3. I suggest projecting geometry

1. Extrude based on Sketch 5
2. Extrude as a subtraction of material 0.25”

1. Fillet the edges of both vertical supports as shown
2. Fillet edges 0.5”

1. Fillet the corners of the horizontal support as shown
2. Fillet corner 1”

This completes the rear Rollbar.

For Printing: suggest printing on the flat vertical face

1. Create sketch shown
2. I suggest sketching a few lines at a time then placing dimensions
3. Start Sketch 1 from the bottom right corner constrained to the origin
4. Use the arc tool with tangent constraint

1. Extrude based on Sketch 1
2. Extrude 18” as shown
3. This will be the width of the “seat”

1. Create Sketch 2 on the front of the “back support” side of the “seat”
2. I suggest starting with the geometry on the left side and using a middle construction line to mirror the geometry
3. After mirroring, close the sketch with given dimensions

1. Extrude based on Sketch 2
2. Extrude 2” as a subtraction of material
3. This will shape the “back support” of the “seat”

1. Fillet the inner edges shown
2. Fillet edges 4”

1. The bottom edge of the “back support”
2. Fillet edge 4”

1. The front edge of the “butt support”
2. Fillet edge 4”

1. The bottom of the front edge of the “butt support”
2. Fillet edge 2”

1. The sides of the “butt support” as shown
2. Fillet edges 1”

1. Create Sketch 3 on the top of the “back support”
2. I suggest using the same method as Sketch 2 and mirroring geometry
3. This will outline the “headrest” part of the “seat”

1. Extrude based on Sketch 2
2. Extrude 2” as a subtraction of material
3. This will shape the space for the “headrest” of the “seat”

1. The sides of the “shoulders” of the “seat”
2. Fillet edges 1.5”

1. The sides of the “shoulders” of the “seat”
2. Fillet edges 1”
3. This fillet should be close to Fillet 6

1. Share Sketch 3
2. Extrude based on Sketch 3
3. Extrude 1” as a shown
4. This will be the “headrest” of the “seat”

1. On the backside of Extrusion 4
2. Extrude 1” as shown
3. This will complete the “headrest”

1. Fillet the top and bottom edges of the “headrest”
2. Fillet edges 1”

1. Fillet the sides of the “headrest” as shown
2. Fillet edges 0.5”

1. Fillet top edges of the “seat” as shown
2. Fillet edges 0.5”

1. Fillet the bottom corner of the seat
2. Fillet edge 0.5”

This completes the Seats of the vehicle.

For Printing: can be printed straight up, support may be needed behind the “backrest,” print as many as desired for the vehicle

Unfortunately I didn't get pictures of the part being printed nor did I capture them while disassembled. Apologies for that, but the part assembly is pretty straight forward and I'll include pictures detailing what was done.

I printed the model in 1:17 scale as that's the max size it could be for the print-plate in my printer. Obviously you can print it at any scaled you like.

Attached is a picture of the printer I used. The model is the Elegoo Centauri Carbon.

Please take the creative freedom to paint the parts whatever colors suit your taste!

I kept my parts mostly unpainted (they were printed in gray and black filament beforehand), except for the headlights (white) and taillights (red). Make sure to use masking tape if you don't want any overspray.

Assuming the body was printed in its 3 split sections as part of the Steps, assembly is very straight forward. Simply align the parts and glue them together, using clamps to ensure they don't move.

In my case, I glued one one the "side panels" of the body to the main middle part first. Then I glued the second side. I just wanted to be as careful as possible to make sure the body lines up as intended.

In the examples above you can see the part lines of the main body in grey (I'll admit it doesn't look too great on the bottom but that's not a part that'll be seen often).

Once the main body is put together, the Front Bumper should fit well with enough tolerance on that front "shelf" section of the body. It should "hug" the sides of the front, and double-check to make sure it's not upside-down!

The Dashboard should fit right into that front curved section of the "cockpit" section of the body. If there's wiggle room in its placement, use tape to hold it down before you glue it.

Try your best to align the center of the driver's side seat to the "gauge-cluster" part of the dash. Then if you printed a passenger-side seat, use the driver's seat as reference on how to center it. I made sure the backs of the seats were up against that "seat wall" separating the "cockpit" from the "bed" of the truck.

The flat part of the rear rollbar should go right up against the "seat wall" in the "bed" of the truck. That way, it's behind the seats and facing forward. Again, it's a pretty simple assembly.

I'm going to keep this pretty brief since this part is going to vary based on what scale you decide to print the model. Basically, The Wheel mounts fit into the axle holes of the body and create an "L-bracket" shape that hugs that bottom corner and sits underneath the truck. The rest of the hub is dependent on the type of wheels you want on the model. In my case I extruded out the cylinder to fit into the entire rim of the wheel for a snug and pretty secure fitment.

A good alternative can be creating wheels in CAD and mounting them through the axle holes. I wanted to leave this part mainly up to whoever is creating this project since preferences are probably going to vary.

If you stayed and followed every step of this project then you've got a pretty nice model in your hands! Thanks for staying through to the end, and I hope you enjoy the fruits of your labor!