Modular "table top" course for 1/30th scale RC crawlers

All of the course sections were developed for my 1/30th scale Axial SCX30 Chevrolet K10 pickup but they are probably suitable for other 1/30th scale crawlers.  This video shows the course being driven.   

Everything was designed using Fusion 360, but I am basically an engineering designer who had to learn how to use the CAD Mesh features to create “organic” rocks.  Thankfully there are a lot of tutorials available, but my early rock designs were quite poor and you can see a definite improvement as I learnt.
The Crown Victoria originated as a free Printables download (thanks to Shoaib Ejaz for creating that model) and I added the “dents” using Blender (another first attempt in the sculpting environment for me).  Shoaib has kindly allowed me to include the modified version of his Crown Victoria in this set, and you can find his original model at  https://www.printables.com/model/1526411-ford-crown-victoria-1992-detailed-3d-printable-car  .
The Saguaro cactus originated as a free Printables download (thanks to Magig_I3Prusa for creating that model) and was adapted for use on my baseplate.  You can find the original version of the cactus at  https://www.printables.com/model/1261863-saguaro-desert-cactus-nosupport-fdm-dnd-trap  .

The majority of the modules are built on a 150mm (across flats) hexagonal base so that you can arrange them as you like against other modules using the joiners.  The “brim” around each joiner was intentional and not a slicer brim option.  Every distinct course element, except for the Seesaw, can be driven in either direction although one direction is often easier than the other.

Everything was printed on my Prusa Mk3 S+ and if you can use the gcode files then all the parts should print nicely.  The 3mf and stl files are also in the download and the information in this document may help you with the print settings.
The oddity you may find if using the stl files is that for some reason a few of the rock plates have rock walls that extend down to the print plate.  That doesn’t happen in the 3mf or gcode files and must be an artefact of the way I created the model in Prusaslicer and then exported the model to create the stl file.  If you find a problem with a few of the stl files then you may need to turn on supports to overcome the issue.

Printing Basics.

Nearly all of the base plates have an open grid pattern.  This makes them faster to print, gives the tyres better traction than smooth flat plastic, and allows the course markers to be inserted where you like.  Everything was printed with a 0.4mm nozzle and all layers were set at 0.2mm.  I used Height Range Modifiers so that the first 4mm of the print had zero top and bottom layers, 3 perimeters, and 20% “star” infill.  That gave quite a small footprint for bed adhesion so I also used a Brim to ensure that the prints remained firmly attached to the bed.  Some parts had colour changes at the 4mm level, and above 4mm generally there were 2 or 3 perimeters with 10% “Adaptive Cubic” infill and up to 4 top layers if the part had a relatively large flat top.
I used Ziro (or CC3d) sandstone “rock” filament for all the rocks and that gave a nice layered appearance on a lot of the rocks.  Printing all the rocks for my 1.5 x 0.95 metre course used three 1 Kg spools of filament, with additional filament used for the “grassy” (green) sections of the course.

Module specific information.

Base Plates without Rocks or Structures.    Simply print all of these with 3 perimeters, zero top and bottom layers, and 20% “Star” infill.

Pole Bridge.    The two poles (or logs) need to be printed on a raft with 5mm spacing “Grid” supports as they have no flat bottom surface.  I used Fuzzy Skin when printing them with a 2mm distance and .5mm thickness setting to create a nice rough surface finish.  The supports and raft broke off the rough finish very easily.  The logs simply rest in the slots in the base (not glued).

Seesaw Module.    This module was a compromise.  The Seesaw had to be short enough to fit on the base plate but long enough to accommodate the K10 and allow it to overbalance while the front wheels stayed on the “ramp”.  I would change things if I started again, but it is driveable and will cause the K10 to do a forward roll as the Seesaw descends if you don’t drive slowly enough so for now it does the job.  The pivot for the Seesaw is a length of 1.75mm filament.

Pipe Module.    This module occupies two base plates, plus a third small base that can be used if another base is not filling part of the space between the pipes.  One of the pipes overlaps onto the other base so you will need to enable supports for the overhang.  I used “Grid” supports with a 5mm pattern spacing.  Fuzzy Skin was used to give a rough texture to the pipes.

Log Pit.    This model was designed in two halves to make two colour printing simple.  The outer base is a simple print, but the inner base and the logs are loaded into the slicer as two individual STLs.  For some unknown reason in Prusaslicer the logs appear to stick through the walls (they didn’t do that in Fusion 360) so I scaled the logs to 99% before merging them with the inner base STL.  The logs need supports so I used “Grid” supports with a 5mm pattern, and found it best to use “paint on supports” on the logs so that the inner base was avoided.  After printing, glue the two halves of the print together.

Crown Victoria.     The basic model for the Crown Victoria was as, mentioned earlier, a free Printables model.  If you need to use the .stl files then the car body and support need to be loaded into your slicer with the car and support both resting on the print bed and the support centrally placed under the car.  Then import the pin holes .stl as a negative volume and position them centrally in the support block.    You will also need to enable supports, I used “Grid” on a 5mm pattern spacing, and add support blockers to cover both the negative volume pin holes.
After printing I cut out the headlights, taillights, and part of the windows to make it look like they had been broken using my Dremel and a dental drill bit.  The hexagonal base plate has locating holes that allow you to position the car in different positions.  The two locating pegs need to be glued into the car with the “pointy” ends inside the car. 
I had intended not to paint the car but found that when I tried to paint the windows the paint worked its way along the layer lines so badly that I had to paint the whole car.  Maybe I should have used marker pens to colour the windows etc.  You may also like to use a smaller layer height as the 0.2mm I used left pronounced layer line on the bonnet, roof and boot lid (hood, roof, and trunk lid).

Rock Arch.    The top section of the arch needs supports when printing.  I used “Grid” with a 5mm pattern spacing.

Course Markers.    These are printed with a colour change for the text, and going back to when I used to compete in Land Rover trials I used white markers on the right and red markers on the left.

Fence.    The posts and railings simply slot together so that you can adjust them to fit anywhere you want.