Robot Arm Expansion Pack Smart Car Starter Kit, Robotics Kit for Kids Ages 8-12 12-16, STEM Toys Coding Robot Kit for Teens & Adults(QD007)

Easy to build worked fine would highly encourage upgrading to better server motors with metal gears plastic strip out quickly.

As others have mentioned the assembly instructions aren't great - it's a YouTube video broken up into steps, with each step prefaced by the parts you'll need for that step, but several times the parts list was wrong which got confusing. The other small issue is that the servos are MG-900s and as such should have metal gears within them (MG == metal gears) but they've been swapped out for plastic ones, the only metal gear is the external one. I learned this after I burned out one of the servos the first time I tried to use it. But overall the kit is pretty nice and it's a great way to learn and tinker with robotic arms on a budget. Since the only electronic components are the servos you don't even need the car kit, I just used an old arduino UNO I had lying around to control it and mounted it to a base plate.

A little difficult to put together. The instructions were not very well written and it was not the most stable even after attaching it to a makeshift table.

I have to leave a two star review. The idea is neat. However, the servos it ships with simply do not have the power, even when externally powered by a large 5V supply (of course the Arduino can't power them) of providing enough torque to function. Particularly the lower two servos on the arm--they can't lift the arm back up. It seems they designed, marketed, and shipped these without actually testing them. I can't believe someone else hasn't commented on this. I ordered 5 and it is a problem with the design.

This is a good product but I did have to return it because a few pieces cracked when assembling so be very careful.

cool design the servos are weak but the parts snap easily 3-hour build time but matches price