FTC Robot Chassis

This is a FTC Robot chassis that can be made instead of a standard GoBilda Chassis. The cost is about the same as their strafer chassis kit but has some benefits:

1. This basic design will create a 403 mm x 408 mm (15.86 in x 16.06 in) chassis versus the GoBilda Strafer chassis which is 440 mm x 451.7mm (17.323 in x 17.785 in). This allows more room to adjust and ways to configure the robot. This also makes the diagonal distance 22.57 in vs 24.82 in, allowing a robot to go through any two points along the outside of a FTC field tile. This is important since most obstacles in FTC have been designed to be placed at the junction of field tiles and the inner edge to inner edge of the field tiles is specified to be 22.875 in.
2. There are no expensive belts/pulleys/gears which, in all honesty, tend to get in the way and complicate the build.
3. There is a potential to create a Power Take Off (PTO) from this drive train which in recent years has become more and more of a potential need for many FTC teams.
4. The wheels are direct-driven from the motors but they have three points of support, two on the inside and one on the outside of the wheel. This severely reduces the possibility of impact forces being translated back to the motor and damaging the planetary gear box on the motor itself.

UPDATED -- The order of assembling some of the side channels was updated to allow for a better sub-assembly. Common screws were also used such that there are only 3 sizes/types of screws (down from 4 previously). Updated BOM is available as both PDF and CSV.

Attached is a full BOM as of writing this. The prices are based on what they were on 8/19/2025. Check prices to be sure that they haven't significantly changed.

SUPPLIES

1. 2 - 10-Hole U-Channel (1120-0010-0264)
2. 4 - Yellow Jacket Planetary Gear Motor (5204-8002-0014)
3. 4 - Quad Block Pattern Mount (1201-0043-0002)
4. 16 - M4 x 0.7mm Zinc-Plated Socket Head Screw, 8mm Length (2800-0004-0008)

INSTRUCTIONS

First, we will build the two motor channels that will house the motors in the robot frame.

1. Take the 10-hole U-Channel and place it on the table so that the open side is facing up.
2. Place two motors into the U-Channel with the drive shafts pointing outwards and away from each other.
3. Slide a Quad Block Motor mount over each of the motor drive shafts
4. Attach each of the Quad Block Motor Mounts to the 10-hole U-Channel with 4 screws (8 screws total).
5. DO NOT screw the motors to the Quad Block Motor Mounts yet. We will do that in the next step.

Make two of the above assemblies.

SUPPLIES

1. Assemblies from Step 1
2. 2 - 16-Hole Low-Side U-Channel (1121-0016-0384)
3. 4 - Flanged Ball Bearing, 8mm REX™ ID x 14mm OD, 5mm Thickness (1611-0514-4008)
4. 16 - M4 x 0.7mm Zinc-Plated Socket Head Screw, 12mm Length (2800-0004-0012)

INSTRUCTIONS

Using the motor assemblies, we will attach the these to the inner side-channel, using the screws on the motors themselves to hold all 4 pieces together.

1. Slide the one Flanged Ball bearing over each motor shaft so that the flange side is closer to the motor.
2. Take one of the Motor Channels and one of the Side Channels. Using 4 12-mm screws, attach the Motor Channel to the Side Channel so that the motor shaft is running through the third large hole of the channel.
3. Attach the second motor subassembly to the first 16-Hole Low-Side U-Channel in a similar manner and with the motor 3 holes in from the other end.
4. Repeat for the other side of the motor assemblies so that you form the main frame of the robot.

SUPPLIES

1. 2 - 16-Hole Low-Side U-Channel (1121-0016-0384)
2. 32 - M4 x 0.7mm Zinc-Plated Socket Head Screw, 8mm Length (2800-0004-0008)
3. 8 - Steel Threaded Plate 2 x 3 (2803-0016-0024)
4. 8 - Steel Threaded Plate 1 x 5 (2803-0039-0007)

INSTRUCTIONS

Prepare two of the 16-Hole Low-Side U-Channels.

1. Take the 16-Hole Low-Side U-Channel and attach a total of 4 2x3 hole steel threaded plates near the end with 8mm screws as shown.
2. The threaded plates should be screwed in through the 2rd and 4th holes from the end of the 16-Hole Low-Side U-Channel on each side and each end.
3. Add a total of 4 1 x 5 hole steel threaded plates to the side channel with 8mm screws as shown.
4. Make one more of these assemblies for a total of 2.

DO NOT TIGHTEN SCREWS - Leave these screws loose as it will assist in the next assembly to ensure that these screws line up with other holes. Once these two Low-Side channels are assembled to the rest of the robot frame, they can be tightened up.

SUPPLIES

1. Robot assembly from Step 2 and Outer Side from step 3
2. 16 - M4 x 0.7mm Zinc-Plated Socket Head Screw, 8mm Length (2802-0004-0008)

INSTRUCTIONS

Attach the Outer Side Rails (built in Step 3) to the rest of the robot chassis by using 8mm long Cap Head Screws and attaching to the existing 2 x 3 threaded steel plates.

Tighten all screws on the 2 x 3 threaded steel plates (those just added as well as those added during Step 3. Leave the screws on the 1 x 5 threaded plates loose until the wheel shields are added at the end.

SUPPLIES

1. Robot Chassis from Step 5
2. 4 - Flanged Ball Bearing, 8mm REX™ ID x 14mm OD, 5mm Thickness (1611-0514-4008)
3. 4 - 8mm ID Spacer, 10mm OD, 7mm Length (1522-0010-0070)
4. 4 - Sonic Hub (1309-0016-4008)

INSTRUCTIONS

For each of the 4 axles:

1. Slide one flanged ball bearing over the axle and up to the Outer Side Rail hole.
2. Slide one 7mm long 8mm spacer over the axle and up to the ball bearing.
3. Slide one Sonic Hub (with the boss extending to the outside of the chassis) over the axle.

Press the Sonic Hub up tight to the chassis and tighten down to lock all the Inner Wheel Hub components together.

SUPPLIES

1. Robot Chassis from Step 6
2. GripForce™ Mecanum Wheel Set (3625-0202-0104)
3. 16 - M4 x 0.7mm Zinc-Plated Socket Head Screw, 12mm Length (2800-0004-0012)

INSTRUCTIONS

Attach the wheels to the sonic hubs using 4 screws each.

Ensure that the wheels form an "X-pattern" with the rollers as shown in the image

SUPPLIES

1. Robot Chassis from Step 7
2. 8 - 8mm ID Spacer, 10mm OD, 12mm Length (1522-0010-0120)
3. 4 - Flanged Ball Bearing, 8mm REX™ ID x 14mm OD, 5mm Thickness (1611-0514-4008)

INSTRUCTIONS

Slide two 12mm long spacers and one ball bearing onto each of the 4 axles. Ensure that the spacers go through the central hub on the GoBilda Mecanum wheels and up to the sonic hub as shown in the image.

SUPPLIES

1. Robot Chassis from Step 8
2. 4 - Pattern Plate, 1 x 5 Hole (1123-0048-0144)
3. 16 - 4mm ID Spacer, 6mm OD, 43mm Length (1502-0006-0430)
4. 16 - Button Head Screw, M4 x 0.7mm, 55mm Length (2802-0004-0055)

INSTRUCTIONS

The wheel shields are meant to protect the wheels from getting objects caught inside them as well as to provide additional bracing for the long motor shaft sticking out of the robot.

Place the center of the 5-hole build plate over the axle and ball bearing. Using four (4) 43mm long spacers and 55mm long Button Head Screws, attach the build plate to the robot chassis. Repeat for all four wheels.

OPTIONAL: The 1 x 5 threaded plates were held in place during construction by some loose 8mm long screws. These can optionally be removed at this time, once the wheel shields are fully attached.