A 180-degree mech arm is one of the most reliable arm styles you can use in VEX IQ. I like this design because it stays compact, moves smoothly, and can be tuned to grab stacked pins without taking up much space on the robot.
1. What a 180° Mech Arm Is
A 180° mech arm rotates from a low pickup position to a high scoring position in one smooth motion. Instead of extending outward like a lift, it stays close to the robot, which helps with balance and consistency.
2. Why This Design Works Well
- It is compact and does not block other mechanisms.
- The motion is smooth and easy to control.
- It can grab two stacked pins in each claw.
- It does not require complex gearing or extra motors.
3. How I Built Mine
- I used a 2×12 beam for the main arm.
- The arm rotates on a reinforced pivot point for strength.
- A claw is mounted at the end and angled for stacked pins.
- Rubber bands are used to help grip the pins so it can grab them without sliping.
- I put the pivot point higher to make the arm smaller (2x12) and thus have more space. This was very important for me.
- For the actual grabbing, I attached the two sides of the arm with a 2x18 or 2x20, and used some of the angled pieces for the claws (the blue or green work best) so it can have more touching points with the pins and can grab better. Also, I found that the taller the claws are then the more surface area they are covering and they grab the pins better. Mine is about 3 inches tall.
4. Tips for Best Performance
- Keep the arm as light as possible.
- Reinforce the arm near the motor and pivot.
- Use rubber bands to reduce motor strain.
- Test the claw angle until it consistently grabs stacks.
- use a big torque gear ratio so your motors dont get fried. Try a 4:1 or 5:1.
If built cleanly, a 180° mech arm can be one of the most dependable mechanisms for the 180 mech vex iq robot. It is easy to tune, easy to drive with, and works well in fast-paced matches.