LittleArm 2C build

A big part of what I want to do in Arduino and 3D printing is to create robots. Years ago, I had some experience in robotics (I helped build a HERO 2000, among other cool projects). But I have found getting back into robotics that I had to step back and learn to build smaller to get the experience I need for future plans. To that end, I decided to assemble the LittleArm 2C. This post will be almost more of a review of the product rather than assembly instructions.

LittleArm 2C is a great STEM project.

The LittleArm series of robot arms comes from Slant Concepts. They have made a series of robot arms based upon the Arduino that students can quickly assemble and learn robotics basics. Plus, they are 3D printable, meaning the projects look can be completely customized. The reason I chose the LittleArm 2C for a project is that it is so small. Yes, I want experience working with servo motors, but I don’t have the room in the office/shop for large robot arms. I think that is also true for a lot of schools doing cool STEM projects. 

3D printing the case

My pictures of the 3D printing process are all gone (thanks to a dead SD card). Printing the pieces was easy to do. The files are not free, however. Right now, the STL files for this robot cost $15. I don’t think that is overpriced at all. Plus, some extra grippers can be downloaded for free.

Below are some of the extra grippers I printed out. The robot arm and grippers were printed out in Glint Green from Filament One. I love the quality of Filament One’s products and look forward to getting my ProFi Box subscription every month. Their glint series is truly unique. It has a very cool texture, and the glint seems to cover up layer lines beautifully.

Some of the extra grippers I downloaded for the LittleArm 2C. I haven’t found time to play with them yet.

Detailed assembly instructions for the LittleArm2C available

I bought a bunch of cheap MG90S micro servos cheap online.

Since there are already detailed instructions available for the LittleArm 2C, I won’t go step-by-step on its assembly in this post. The assembly itself is effortless. I don’t think it took very long at all to assemble the arm. I had a slight problem with the gripper pin screws because I couldn’t find the required size published. I used some screws that seem to work OK, but I would have liked a heads up on what size to use.

The electronics parts utilized in this build I ordered from Slant Concepts. If I had realized what servo motors were being used, I might not have ordered those from Slant. I happen to have many cheap MG90S micro servos on hand already, and I might have saved a few dollars there.

The other heads up I might have liked was the wire used for the gripper. I don’t have a thick enough wire on hand for the gripper to work correctly. The next trip to the hardware store will fix that. But I wish the instructions had some heads up.

LittleArm 2C printed, assembled, and mounted on my wall.

Using the apps to control the arm

Honestly, I had very little luck using the windows app. If you use the windows app, the Bluetooth module cannot be connected. Plus, you cannot upload sketches to Arduino if the Bluetooth module is installed. But, even with the Bluetooth module disconnected, the windows app was very slow to respond.

LittleArm 2C android app.

A better option is to use the Android app. The app works great and can be downloaded from the Play Store. All you have to do is pair the Bluetooth module up to the phone and choose that Bluetooth device in the app.

To move each of the four servos, simply move the sliders. You can then make a move and hit record. After enough movements recorded, simply hit play. That is training at its simplest. I wish the app had a nice save feature for training, but that isn’t a big deal that it doesn’t. Here is a look at the interface.

Here is a short sequence I recorded of me training the LittleArm 2C.

Training the LittleArm 2C.

Future of my LittleArm 2C

I have many other projects going on right now, so it might be a while before I get back to playing with this particular robot arm. But I plan to use this arm to control the webcam I use at my desktop. I will use sensors to have the arm keep the camera pointed at me as I move around in my office/shop (or basement man cave as the wife calls it).

I think this was a fun little project and think it would be appropriate for use as a middle-school or high-school STEM project. Its small size makes it exceptionally pleasant since it won’t take up a lot of valuable desk space (or wall space in my case).

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