The LittleArm Educational Robot Kit and the Mearm Robot kits have a lot of similarities. The they are both small robot arms designed to be programmable and help kids learn about STEM. They are both arduino robot kits. But beyond that these robotics kits are very different.
The first LittleArm was created in the fall of 2016. It was successfully funded on Kickstarter soon after. The second arm, which is now the standard was created in the Spring of 2017.
The LittleArm 2C has only 31 parts in the entire kit. This was intentional as it was meant to the be simplest robot arm kit for beginners out there. This was possible because all of the primary parts for the 2C are 3D printed. 3D printing allows parts to snap together and have geometries that eliminate screws.
In addition to a very good mechanical design the 2C ha great electronics that also ease the introduction to robotics. The primary board is an Arduino nano that is seated in the custom circuit board that allows easy connection to servos, Bluetooth, and other sensors. Since each lead is labeled with its function kids can see where they can add expansions without being distracted by minutiae like the difference between an analog and digital pin. The kit also is entirely plug and play. There is no soldering or other specific skills needed to put it together.
Once built the arm can be trained, just like industrial robot arms, to perform repetitive tasks by using the Android phone app for the Windows Desktop app. This really helps to detail how real-world arms operate. Out side of the normal training code there are tutorials and code examples that hobbyists can expand on.
One disadvantage of the LittleArm is that sometimes the pieces can be difficult for younger ages to press together. Think of two Legos stuck together. They might need a little adult help to do it.
But overall the LittleArm was designed to eliminate complexity in getting started with and building robots. It is a clean sleek kit that eliminates many stumbling blocks in understanding the main concepts of robot arms.
The MeArm was created by Benjamin Gray and was launched on Kickstarter in December 2014. It was funded successfully and has been the lone DIY robot arm in the world until the Littlearm was made.
The MeArm is made from lasercut components that are screwed together to create the small robot arm. Laser-cut components allowed the MeArm to be manufactured very affordably, so it could grow and gain audience organically. But Lasercut components result in many pieces to have to assemble. A MeArm kit has near 100 pieces.
The MeArm has the same basic structure at the LittleArm. It has four joints that are controlled by an arduino board. But the MeArm uses a parallel arm design, which ensures that the gripper is always horizontal.
The electronics of the MeArm vary from one kit to the next. The 100 dollar kit includes all of the components necessary to make a MeArm work. The most common package is an Arduino Nano and some button-based control board (buttons or joystick variations). These must be assembled with jumper wires based on included wiring diagrams. Some kits to need a little soldering, but this is not common. Newer MeArms have improved labeling of leads but they are not quite as good as the LittleArm labeling.
Since is has existed for longer the MeArm does have a wide support base. There are many tutorials and resources and code examples. But these can be disjointed. Beginners can have trouble getting started. The MeArm is also not always compatible with the apps that exist for it.
Overall the MeArm, is a good kit for experienced hobbyists. But is can be intimidating to very young builders who are not familiar with all of the electronics and hardware. But it's greater software base does help with expansion.
Price-wise the two kits are the same. Either one, with all of the control boards and components needed to make a working arm, are around 100 dollars.
It is hard to find educational robotics kits for kids. But if you are looking for an robot arm kit for your child or your student the Littlearm and the MeArm are the best choices out there. It is your choice which you think would be more appropriate.