The 12x9 aluminum pattern plates specified in other parts of the rover documentation have been discontinued by ServoCity. The included top_plate_baseline.dxf and bottom_plate_baseline.dxf can serve as replacements.
These plates are the same size as the originals, so everything else is the same except for items noted below.
The plates should be laser-cut using 1/4" or 5- to 6-mm plywood or MDF. Acrylic is likely to be too brittle for this purpose. Online services such as Sculpteo can do the laser cutting if needed.
It really doesn't matter if you use plywood or MDF, although there are slight advantages to each.
MDF (medium density fiber-board) from online services such as Sculpteo is an easy choice. It is a bit cheaper than plywood and comes in multiple colors for an additional cost. If buying MDF from Sculpteo, choose 6mm for the thickness.
Sourcing MDF requires care if you are cutting the plates yourself. Some MDF has a high formaldehyde content, which can be toxic. If you are cutting the plates yourself, a high-quality plywood is probably your best choice.
Plywood might cost a bit more from online services, but the cost increase should be minor. Plywood has advantages if you are cutting the plates locally due increased availability and to the possibility of formaldehyde in some MDF products. If using plywood from Sculpteo, choose 5mm for the thickness in either Okoume or Poplar, depending on the color you want.
The laser cut replacements are approximately 1/8" thicker than the original aluminum plates, so all screw sizes need to be increased by 1/8" to compensate.
- Use 3/8" screws (B2) instead of 1/4" screws (B1) to attach the plates to the side mounts,
- Use 1.25" screws (B7) instead of the 1" screws (B6) when assembling the differential pivot block.
Use #6 washers (W1) with the 3/8" screws when attaching the side mounts to prevent the screws from digging into the plywood or MDF.
The laser cut top and bottom plates have holes for two extra side mounts on each plate. These extra side mounts are intended to compensate for any warping in the plywood or MDF. Their use is optional.
- front_plate.DXF and back_plate.DXF can be cut from the same material as the top and bottom plates if desired. These plates should remain as 1/8" or 3 mm thick.
- The holes to mount the head have been moved forward slightly to allow for additional clearance between the head and the PCB.