Picture of Pocket Sized Robot Arm #meArm V0.4

The #meArm is a Pocket Sized Robot Arm. It's a project started in February 2014, which has had a fantastically fast journey to its present state thanks to it Open Development as an Open Hardware project. Version 0.3 was featured on Instructables back in April 2014 and we've seen it built all over the world, from its home in the UK to the USA, Mexico, Switzerland and Japan to name but a few.

All of the previous builds have helped us iterate a thousand tiny improvements to the current version the v0.4 which is most likely going to be our v1.0.

All of the previous versions and this can be found on thingiverse.

This guide covers how to build the v4.0. Currently there is code available for the Arduino, Raspberry Pi, Beaglebone Black and Espruino.

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Step 1: Gather your parts!

Picture of Gather your parts!
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The #meArm was designed with economy in mind. It is understood that laser cutters aren't the most common tools but there are more of them out there now than ever! First you'll need a set of parts. Grab the dxf and use a cnc mill or laser cutter. For the v0.3 we also had people 3D print the parts. If you get a kit from us or order the parts in acrylic you'll have to remove all of the protective covering. It's not the most fun job but the end result is better!

Next you'll need all of the screws and nuts. We use M3 (metric 3mm) standard parts. The number of these to build the latest version is:

Nut x 10
6mm x 9
8mm x 12
10mm x 3
12mm x 7
20mm x 4

You could no doubt find imperial sized counterparts, as a nation you managed to get a man to the moon with foot pounds per square inch so I'll leave the conversions in your capable hands (in case of residents of Liberia or Myamar ignore the bit about the moon).

You'll also need 4 hobby servos. We tend to use the 9g resin gear ones. The metal gear ones with the same footprint are better but they're more expensive.

Phenoptix is a commercial operation (when I remember) and we do have complete kits available as well as the component parts.

ted99tw made it!1 month ago

Thanks and I made a Chinese one. Enjoy!

nawres1022 months ago

Video please!

phenoptix (author)  nawres1021 month ago

Just a few of them here. From my kitchen table to Taiwan, Japan, Mexico and the USA!

borodatch2 months ago

Awesome project! Thanks.

Please, tell me a thickness of material.

phenoptix (author)  borodatch2 months ago

It's 3mm acrylic, 1.4" is about right I think (excuse me if that's wrong I used my mental google and it's not as good as the real thing...)

3mm =~ 0.118". 1/8" = 0.125".

jstaněk12 months ago


Really awesome project, I did something similar, but much bigger.

Anyway, how thick is your acrylic sheet?


phenoptix (author)  jstaněk12 months ago

That's a cool arm! This used 3mm Acrylic. What in the box?

Thx :-)
The whole box works like a controller. Inside of it is 5 potentiometers (each of them control one axis od the arm), few resistors for calibration and power switch. Under the arm is then Arduino Uno R3. (labels on the whole arm and controller is in my native language).


great work indeed!

Thanks :-)

amirbmw1 month ago
What a cool project
JON-A-TRON2 months ago

Video please!

phenoptix (author)  JON-A-TRON2 months ago

Have a few of the v0.3, will have to get the camera out!

Imperial sized counterparts, indeed!
This is a splendid Instructable... I look forward to making one of these in the very near future.
phenoptix (author)  crispernakisan2 months ago

Thanks for your kind words! Look forward to seeing your #meArm!

crispernakisan Looks like 4-40 bolts are close to 3mm

GastonLagaffe2 months ago


I have three of these (0.3 and 0.4) - they are great. I only replaced the center servo by a metal gear one for better weight tolerance. I took pictures of the build process:

Enjoy this lovely robot!!!


phenoptix (author)  GastonLagaffe2 months ago

Thanks for your support Mathias! Think yours is still the best build tutorial!

ravepants2 months ago
Fantastic project!
phenoptix (author)  ravepants2 months ago

Cheer for all your support Kia. Pool-table laser is calling to me! Need to find some windscreen wiper motors...

forbesg2 months ago

I am having trouble with the dxf file. I use a cadlink program for my GCC laser. When I import the file there are a jumble of extra lines. When I import it to inkscape some of the parts are incomplete. However I can save the file as a dxf and then import it into my cadlink program. There are still incomplete parts showing. Is there a clean file available? Thanks for any help.


phenoptix (author)  forbesg2 months ago
Hi there,
Just verified what you say is true with inkscape. Don't know why this is and I've always had problems with dxf and Inkscape. Which is a shame as it's a great bit of software.
The file works for my laser, using lasercut, as well as in corel and autocad. Have tried saving via autocad rather than corel but although it is better all of the circles have become tear drops!
I'll work on this when I get the chance and let you know.