Parallel Plate Drivetrain
Sandwich-plate chassis with bearings between the plates. The most common FTC drive-base architecture — robust, repairable, and easy to package mechanisms inside.
Before you start
Start from the Bearing Stack tutorial — you'll repeat that pattern four times. You also need 4 motors, 4 wheels, and a pair of side plates large enough to keep the robot inside the 18-inch sizing cubeFTC robots must start each match fitting in an 18" × 18" × 18" cube. Your chassis sets the floor; whatever you mount on top has to share that envelope until it expands..
1Draw the layout sketch first
Before any parts, sketch the chassis outline on the top plane: wheelbase, track width, and motor mount positions. Master-sketch everythingIf wheel positions live in a single sketch, you can re-tune the wheelbase by changing one number. If they live in 4 separate sketches, you'll forget one and crash a wheel. here, then drive the parts from this sketch.
Leave ~0.5" of slop inside the 18" cube on each side — bumpers, electronics, and your scoring mechanism have to fit too.
2Model the two side plates
Extrude the side plates from the layout sketch. Cut bearing holes, motor bolt patterns, and lightening pockets in the same part studio so they all live on the same parametric history.
Add attachment patternsPre-pattern a grid of 5mm holes on a 16mm pitch (or whatever your structural extrusion uses). Future-you will thank past-you when mounting unanticipated parts. across the unused face area before you cut your specific bolt holes.
3Stack the bearings, shafts, and wheels
Re-use your bearing-stack subassembly for each of the four wheels. Insert four copies, mate each Fastened to a wheel position from the layout sketch.
Wheel choice matters: mecanum vs tractionMecanum gives you strafe with one motor per wheel but loses pushing power. Traction wheels are stronger but only drive forward/backward. Pick based on whether you'll be defended. drives the rest of the architecture.
4Mount the motors
Drop 4 motors into the assembly, one per wheel. Use the motor's mate connector to fix it to the side plate; constrain the output shaft Revolute through its bearing.
If the motor body extends inboard past the bearing, watch your packaging — it'll eat into the space where your intake or lift has to live.
5Tie the plates together
Cross-brace the two side plates with structural extrusion or sheet-metal cross-members. The drive base is only as stiff as the connection between the plates; an under-braced chassis flexes and the wheels toe out under load.
Final check: drag a wheel in the assembly's Play view. The opposite wheel on the same side should rotate; the other two should stay put.
You have a working drive base. From here you can swap wheel types, change the wheelbase from the master sketch, or add a strafing axle — the rest of the robot bolts on top of these two plates.