Robot Chassis Base

Generate an OpenSCAD script for a 3D printable robot chassis base. The base must be a flat rectangular plate of exactly 200x200 mm with a thickness of 4 mm. Place the origin (0,0) at the bottom-left corner. The bottom edge (Y=0) is the REAR of the robot, and the top edge (Y=200) is the FRONT. Perform the following boolean operations: Wheel Wells: Subtract two rectangles on the left and right edges at the rear. Left well: X=0 to 35, Y=0 to 70. Right well: X=165 to 200, Y=0 to 70. Encoder Slots (HORIZONTAL): Subtract two horizontal rectangular slots parallel to the X-axis. They must be located 14 mm inwards from the wheel well cuts. The dimensions of each slot are 25 mm wide (X) by 10 mm tall (Y), centered at Y=41 (which is 3cm + 1.1cm from the bottom). Left slot: X=49 to 74, Y=36 to 46. Right slot: X=126 to 151, Y=36 to 46. Battery Cable Hole: Subtract a 10x10 mm square hole in the center rear to route the battery cable. Center it at X=100, Y=30. Ball Caster Hole: Subtract a circle with a diameter of 4 mm centered at X=100, Y=166. PCB Mounting Holes: Subtract four circles of 3.2 mm diameter (for M3 screws) forming an 80x60 mm rectangle, centered at X=100, Y=110. (Hole coordinates: X=60/140, Y=80/140). Motor Cable Routing Holes: Subtract two 10x10 mm square holes for motor cables. Left hole centered at X=45, Y=80. Right hole centered at X=155, Y=80. Arm Area (Visual Guide): Instead of cutting through, create a 0.5 mm deep engraving (subtract a 0.5mm deep box from the top surface) for a 100x100 mm area at the front (from X=50 to 150, Y=100 to 200). The script must be clean, well-commented, and use variables for dimensions so I can easily adjust the parameters later. Output only the OpenSCAD code."

Parameters

Every value above is a live dimension. Open a model like this in the editor and each one becomes a slider you can drag before exporting.