Start with the build completed in Lesson 3 of the TETRIX Getting Started Guide. Steps 1 to 3 involve removing elements from the model. These elements will be reattached later. Parts to be Removed Step 1 2x 1.5" SHCS 2x Kep Nut 1x Left Motor Assembly Make sure to unplug the battery before making changes to the electrical system. Keep the screws and kep nuts. These parts will be used to reattach the motor mount in Step 7. 183
Add-On Gears Parts to be Removed Step 2 2x 1.5" SHCS 2x Kep Nut 1x Right Motor Assembly Keep the screws and kep nuts. These parts will be used to reattach the motor mount in Step 8. 184
Parts to be Removed Step 3 2x 3" Wheel 8x 1/2" SHCS 2x Keep the screws for the next step. Complete Steps 3 to 5 on both motor assemblies. 185
Add-On Gears Step 4 1x 40-Tooth Gear 8x 1/2" SHCS 2x If it is not already, rotate the motor within the motor mount so that the motor shaft is closest to the gap in the motor mount. Make sure the axle hub is placed approximately 1/4 from the face of the motor, so that the 40 tooth and 80 tooth gears will align. 186
Step 5 4x 1.25" SHCS 1x 3" Wheel 1x Gear Hub Spacer 1x 80-Tooth Gear 1x Axle Hub 2x Align the holes on each of the components by taking one screw and stacking the wheel, hub spacer, and 80-tooth gear and then screwing the screws into the axle hub. Insert the other three screws into the aligned holes. 187
Add-On Gears Step 6 1x 32 mm Channel 1x L Bracket 2x 1/2" SHCS 2x Kep Nut Make sure the screws are in the correct holes. The holes in the small channel and bracket elements should be aligned with the holes in the 288 mm channel on the chassis before tightening the screws. These holes must be aligned in the next step. 188
Step 7 1x 32 mm Channel 1x L Bracket 2x 1/2" SHCS 2x Kep Nut Make sure the screws are in the correct holes. The holes in the small channel and bracket elements should be aligned with the holes in the 288 mm channel on the chassis before tightening the screws. These holes must be aligned in the next step. 189
Add-On Gears Step 8 2x 1.5" SHCS 2x Kep Nut 1x Left Drive Gear Assembly The motor should be rotated within the motor mount as shown, with the motor shaft pointing toward the back of the robot. 190
Step 9 2x 1.5" SHCS 2x Kep Nut 1x Right Drive Gear Assembly The motor should be rotated within the motor mount as shown, with the motor shaft pointing toward the back of the robot. 191
Add-On Gears Step 10 2x Bronze Bushing Make sure the bushings do not fall out before or during the next step. 192
Step 11 1x 100 mm Axle 1x Axle Set 1x 3/8" Axle Spacer Collar 1x Wheel Assembly You might need to turn or jiggle the wheel assembly to make the gear teeth interlock with each other. Make sure to tighten the set screw on the axle set collar to lock the wheel in place. There should be no space between the wheel assembly, axle spacer, and bronze bushing. If the gears are not aligned, loosen the set screw on the motor hub and adjust the position of the 40-tooth gear so it is aligned with the 80-tooth gear. Remember to tighten the set screw. 193
Add-On Gears Step 12 2x Bronze Bushing Make sure the bushings do not fall out before or during the next step. 194
Step 13 1x 100 mm Axle 1x Axle Set 1x 3/8" Axle Spacer Collar 1x Wheel Assembly You might need to turn or jiggle the wheel assembly to make the gear teeth interlock with each other. Make sure to tighten the set screw on the axle set collar to lock the wheel in place. There should be no spaces between the wheel assembly, axle spacer, and bronze bushing. If the gears are not aligned, loosen the set screw on the motor hub and adjust the position of the 40-tooth gear so it is aligned with the 80-tooth gear. Remember to tighten the set screw. 195
Add-On Gears Final View 196
Wiring Diagram Tighten the screws on the HiTechnic controller after the wires have been inserted. Complete all wiring before attaching the battery. 197