Mechanics

Overview

　Mechanics This term primarily refers to a robot’s mechanical structure. It is a crucial element that not only plays a major role in determining the robot’s appearance but also dictates most of its physical movements. In this context, we will proceed with the discussion using the term Chenom wheels."

Mechanical Components	Description
	Assembly of the mechanical components, including wiring to the motor control board and the motor

Frame

　The frame features a rigid structure, consisting of six 15mm x 15mm x 130mm aluminum frames from Misumi.A distinctive feature is the use of L-shaped brackets on the frame—which acts as a beam connecting the front and rear wheel sections—to create a stepped design that reduces the overall height. This lowers the vehicle’s ride height, which in turn lowers the center of gravity, improving stability while giving the bike a sleeker appearance.

Step Caused by an L-Shaped Bracket	Description
	Although it’s upside down in the photo, there’s a step caused by the L-shaped bracket.

Installing Spacers - 1	Description
	Installation of Spacers for Mounting the Motor Control Board

Installing Spacers - Part 2	Description
	A view of the entire frame from the front left

Motor

Motor Appearance	Description
	The motor is a geared motor with a diameter of 25 mm. It’s this type. To be precise, it’s not exactly this specific product. The key is that it has a 25 mm diameter, runs on 12 V, and comes with an encoder. You can find it on AliExpress, but be careful—shops on AliExpress tend to disappear without warning. The gear ratio has now settled at 150 rpm. This, too, has gone through some changes. Initially, I was using a 400 rpm motor, but after replacing the motor driver, efficiency improved dramatically—the motor sped up so much that it became difficult to control. Even at 270 rpm, it was still too fast. That’s why I settled on 150 rpm.

Motor Appearance

Description

　The motor is a geared motor with a diameter of 25 mm. It’s this type. To be precise, it’s not exactly this specific product. The key is that it has a 25 mm diameter, runs on 12 V, and comes with an encoder. You can find it on AliExpress, but be careful—shops on AliExpress tend to disappear without warning. The gear ratio has now settled at 150 rpm. This, too, has gone through some changes. Initially, I was using a 400 rpm motor, but after replacing the motor driver, efficiency improved dramatically—the motor sped up so much that it became difficult to control. Even at 270 rpm, it was still too fast. That’s why I settled on 150 rpm.

Motor Installation - 1	Description
	Next, let’s take a look at how to install the motor. Use this part as the mount. Secure it by threading a nut through the groove in the frame. This mounting part also secures the frames together.

Motor Installation - 2	Description
	Place the motors one in front of the other; the layout should look like the one in the photo.

Meccanum Wheel

Fastening section	Description
	A key feature of Robocar is the Mecanum wheel. The Mecanum wheel is mounted coaxially on a geared motor. Apply threadlocker when securing it in place.

Wheel Arrangement	Description
	Pay attention to the wheel arrangement as well. Arrange the wheels so that the barrel-shaped sub-wheels positioned diagonally on the wheels form an X." This arrangement creates a unique motion.