MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.

Download Now



by daGHIZmo Apr 6, 2016
Download All Files

Thing Apps Enabled

Please Login to Comment

I see that the gears doesnt match. Do you have the exact modulus you used? So I can easily reverse engineer them.

Already found: For the small gear (22 teeth) you used a Pitch Circle Diameter of 37.5 (So, modulus is 1.704...) and for the large gear (50 teeth) you used a modulus of 1.5 (so Pitch Circle Diameter is 75). Modulus have to be the same for a fit.

Do you happen to know the weight of the arm+servos+hardware? For this and perhaps also for the MKI? I'm considering mounting it on a mobile base, and wondering, ballpark, how feasible that would be.

The electric setup doesn't work at all no matter how precise the wiring is done even when installed perfectly by the instructions . Checked the wiring and the resistances more than 10 times and even then the servos just jitter a bit but moving the arm even 1 mm coordinated isn't working even with the correct Software. A huge waste of time and Material because it's just usable as stationary model. Also a faq on problems isn't available what makes fixing the problems nearly impossible when you are not a professional electrician
The model itself is well made but the electric ruins everything

Very cool project! Excuse me, if my question seems to be stupid: Isn't it necessary to use a motorshield if I want to use the arm with an Arduino Uno?
I want to build these arm with my students in the future and for that reason I try to keep the costs as small as possible. I'm really new in this topic.

Built one and it is a GREAT design, however I have a problem for which I'd like to see if anyone can give me some good advice. The main arm servo has a tendency to overheat if the arm is, well, in many of the positions, as it is sitting still. That servo in particular can get very hot, I even had smoke coming out of one of them. I am running the bot with MG995 servos. I'm concerned that if I use these in a classroom setting I will burn through a lot of servos.

I feel like it is the weight of the arm and the small actuator plastic arm putting torque on the servo, but I'd like some other opinions or recommendations, because this little robot arm could be extremely useful in education!

System is run using Python and a pwm hat on a Raspberry PI 3.

I had never used the arm so often that I could recognize this behavior.
A servo acts like this:
I put in a desired angle via a PWM signal and the servo try to move to this exact angle. If the servo can't because the force against the movement is too high, the servo motor trys all the time to move to this position.
It could be that the main arm is all in all to heavy and the servo could not moves it to the exact desired position and the motor always drive against this.
Sometimes you can hear if the motor is running or is trying to move to the position while the arm is not moving.
It could be that the mechanics are not moving free enought so you produce the to high internal resistance.

Another point is what I realized is that the main arm controled by the right servo and the upper arm controlled by the left servo, don't have total freedom in every position.
If the upper arm is in its uppest position (so the servo is on the downest position) you can't drive the main arm to its most forward postion, without driving the upper arm more down. This causes if you don't controll is properly that both servos working against each other.
I hope you know what I mean.

Totally agree. My freedom of movement is not a factor, the arms swing freely without servos connected, etc. The servos do sometimes complain audibly, but this is not the case when the base arm one heats up. I really think it is the weight of the arm and the small plastic servo arm not having the torque to hold the base arm in some positions/angles. I am now looking into seeing if there is a way to cut power to the servo via the pwm port on the Pi Hat for that servo once a movement has been completed. at least that way I won't burn them out sitting still. Any other suggestions to workarounds gladly taken :)

Comments deleted.

Is it programmable or do you control it manually?

I built one using a Raspberry Pi 3 and a pwm hat, using Python. Have it controlled via a small GUI app I wrote, or you can set it up to work with controllers providing direct input to the servos.

tl;dr - can work both ways

Ciao, prima cosa voglio ringraziarla per avermi fatto appassionare sempre di più alla stampa 3d e mi inorgoglisce vedere che in Italia ci sono ancora persone con le sue capacità, adesso ho iniziato a stampare l'MK2 e sembra procedere bene, ottimo lavoro complimenti!

Great job! Thank you for the model.

What is the purpose of the second fully 360 degree big gear included in the files?

Teeth matching of the gears. Use the one that fits best and gives free rotation.

does this robot arm have five axis or four ? can anyone answer ??

4 axis, technically: base rotation left/right. Main arm - up down, with extender arm in/out, and claw open/close.

Awesome and very easy design, it will help me to understand basics of robotics and arduino. Thanks a lot for it. I have made base plate for arduino, so you can check on link below.


EezyBotArm MK2 base plate for arduino uno clone
by XVavron

Grande Carlo sono rimasto basito.
Comunque la qualità di stampa è ottima,bella stampante la tua autocostruita.

Ti ringrazio Emanuele

For anyone else who had trouble trying to use cartesian coordinates (eg. x and y) for their arm, I created some example code here: https://github.com/IdreesInc/EEZYbotARM-MK2-Cartesian-Coordinates
Note that this code assumes you have a Raspberry Pi and the Adafruit Servo Hat, but you can use the math in any system that allows you to set the servo angles (I believe Arduino lets you do this off the bat?).
EDIT: Turns out the proper term for this is robotic kinematics

I bought 3 Tower Pro MG946R servo but one of them which is attached main base is only move one way.

so is there anybody in this situation

Did you make sure the servo was at center position when you mounted it? I'm having a heat issue on the base arm servo myself.

I want to thank you for making this and the original cad files available, and I was wondering if you could also make the original unbuilt aia file from the MIT app inventor available for download as well. I also use that suite and I'd love to see how you did that

i like model but need model were used stepper motors nema 23 or 34 size motors and maybe marlin software too.then have usefull and good childrens education project.only clamp hand used at sevo have better usefull.

Cool looking robot. Looks like it wouldn't be hard to connect the servos to a receiver and program a RC transmitter to do the controls.

It's definitely a beautiful design and looks like they put a great deal of time modeling it up.

I did print and build one but had to make some modifications due to the servo's I purchased.

Summary suggested (3) 946 servos so I purchased (3) MG946R servos but the control servo arms that came with the MG946R's were quite large and would never been able to fit into the recessed area they were meant to fit into so I had to break out the calipers and back engineer mine and model up both cone shaped servo arms and also the round arm needed on the main base boom gear. With that being said the MG946R's that I purchased also appears to only had a 60 degree turn angle so using one for the main base boom with the gears provided from the STL files the left to right swing was only moving my boom 2.5 inches so I ended up ordering a 270 degree servo for the main base gear. Maybe I purchased the wrong 946's not sure if there maybe others to have chose from but mine only traveled 60 degree's which worked ok for controlling the upper and lower boom's but the swing left to right was not enough degree of movement. I guess if your going to purchase 946 servo's see if you can see if they show some photos of the servo arms that might come with it and what degree of travel they supply.

Hello everyone. We are developing ARDUINO based control board for this robot. Video and links to our files are on :


Do you have information about this?

I have all the 3d printed Parts.
I want to give the parts somebody for free. I only wanted shipping costs.
So who is intrested? Please contact me.

I have the Mini Maestro 12-Channel USB Servo Controller too, if you want to buy them, you can get it from me for 18€.

Please quote for shipping to Ireland. Both for printed parts and the Mini Maestro 12-Channel USB Servo Controller. Cheers!

Hello Michael,
thank you very much.
Shipping to Irland costs 9 € for all parts and the controller.

If you have interest please send me a message via thingiverse.

Kind regards Alex

How much would shipping be to Texas?

Hi laserkil,

for the printed parts or the usb servo controller?
Or for both?


I have a question. Has anyone made reverse kinematics to this manipulator? I plan to implement kinematics, but for now I have a problem with that. I can't find the right book that describes it well. Can anyone help?

We are in luck. This is a scale model of a commercial robot. The kinematics are publish for the full size one. I guess you just divide by 7

Here is scale drawing

Kinematics worked out (Google will find more)

Even better code that implements it

Again the nice thing here is that this robot is really common. Lots of people have maked scaled version some in plastic and some in metal. I have a metal version. I'd like one of these but slightly larger with steppers. and interfaced to ROS/Moveit software. Working in that slowly....

One wonders what people are doing with this Robot if they don't have RK worked out? Joystick teleoperation I guess.


Great work!
Could you upload an assembly from the whole robot? I'm interested in the height of the robot when axix 2 and 3 are at 90 degree.

How much do you think this would cost to make, and do you think a 13 year old who hasn't built much like this would be able to make it? Thanks!

How did you get the 2 servos on the side to stay, mine keep popping out of the sockets

You have to use the screws provided with the servo. There are holes prepared in the base to mount them.

Beautiful machine, definitely want to make one!

The main base STL doesn't seem to have the holes for the servo neither the space to fit the cable of the servo when inserting it.

good project and well explained, only that I have a doubt and I want to ask you how would you do to make it work with a color sensor and arduino one? since I can not think of the perfect way to do it since I am a beginner in this. I would appreciate it if you could advise me. for any matter I leave my mail. ferramo93@gmail.com thank you very much.

I have a few questions on supports since this is the first time I have needed them. I'm using Prusa i3 MK2s and Slic3r for Prusa and printing with PLA. The first print I tried was the 002_mainarm... I did not use supports and didn't think it would work but tried anyway and what the heck, it didn't work. I see the some people printed this and say they didn't use supports but when it comes to the upper layers and goes out hora on each end with nothing under... I just don't see that making it without a support of some kind.

So I turned on supports in Slic3r and it put accordian shapes all over at both ends. The print completed and at the smaller end it looked pretty good after removing al the support material. But on the larger end there was some deforming as the base layer (on top of support) was not stable. I think is is usable but I might try to print that again.

Then I printed the 006_horarm with supports. My supports did not look the same as in the authors video (rounded and out to the side, my supports were directly under and not going out to the sides) but they did work but leaving a very messy surface on the end the curves up where the main supports were. I might try wet sanding that section.

So I guess my question is can that 002_mainarm & 006_harz armbe printed without supports somehow? And also what are people using for slice software and any special settings to keep the supports working but leaving less of a rough surface? Maybe my prints are good as far as support prints go... that's what I'm trying to determine. Thanks for the help & advice, I look forward to completing this very cool robotic arm!

Some photos of the prints..

For the folks that programmed your own code:

Did you realized the issue with servo 2 and 3?
You can't move the servo 3 (the front warm) independed from the servo 2 (main arm).

Example: If main arm is fully back, you can only move the front arm less degree. The same is when the main arm is at fully front position. Only at middle position you have the full 100° freedome for the front arm.

How you solve that problem in the code, especally for manuell controlling?

I have some pictures attached to make it more clear.

In other words:
The maximum available angel for operation for the front arm is only useable in a middle positions on the main arm (100°). It became smaller in front and back position for the main arm (75° and 55°).

I noticed some of the physical limits myself, that's actually not too unusual for these types of arms depending on the actuator arms, etc.

I am currently working a Python GUI that has rough moves, solving an overheat problem on my base arm actuator, and I'll post any useful code for movement I complete. I want to use a couple of these in the classroom, mine uses a Pi3 with a decent pwm hat. I am working the manual moves library/GUI then I will work controller type buttons as well in Python. Using this to teach programming so over the next 12 months I should have some decent examples to share. Only thing slowing me down is a servo that likes to overheat.

Can I buy this robotic arm? Assembled and functional. With control software.

How do you print this? I cant print in the glass (heated bed); I need to put pve glue to stick my filament in the bed!

A great project.... Does it support MeArm library... Can I use MeArm library with this robotic arm....???

My servos didn't come with the circular horns. Where can I get a replacement for those?

This looks awesome!!! I Think I'll need to fit this on the back of the Pistenbully that's currently in production at my place.
Are there any way of tilting the claw individually, I might have missed it somewhere :)

Very nice job, it would be nice if you could add the lenght and the size of the screws in the instructable, its very difficult to see which one you have to use

Comments deleted.

In the stl the Lower base (13 part), the center hole doesn't go through, it has a thin layer.. do I need to puncture it? It doesnt seem to be there in your schematics.

Here are the discrepancies


Thanks for all the hard work and your dedication to open source this. You are an inspiration.

yes you have to open the center hole,
I modeled the part in this way just to avoid supports. In this way the printer make bridges providing a stright roof. If you make an hole with a large roof unsupported, the printer start to print the center wall and it drops down

Hey guys. I have POLOLU-1352 Mini Maestro 12-Channel and I am planing to run 2 of EEZYbotARM MK2 on it.
List of servos I have and would like to use are:
MG995 Metal Gear x6
MG90S x4 for the gripper (I am considering to have custom griper with dual MG90S servos providing the rotation of the gripper)
My question is really beginner like.
What would be the min/max battery I should have to make it run at max speeds? I just dont want to have a bottle neck when it comes to power. PS I dont want to use a power supply unless it is cheaper then the battery and there is no addition upgrades required. I am over the budget already
I am new tho electronics... so please consider it when you giving an answer. Cheers!

I see that all gears in this model are compatible, the ones in the hand and in the base. How can I design more gears compatibles with those?

The arm connected to the claw is link147 or link135?

147 ... the claw have to move parallel to the groundplane

Modified the claw mount add a 5th servo for rotation.

EEZYbotARM MK2 Rotating Claw Servo Mount

Is it possible to make bigger end effector(claws)? So it could grab small plastic tubes with radius of 4cm?

Hi, what kind of power supply did you use to power this?
Did you use batteries with a BEC or just a 5/6v power supply?
Have you checked what's the max current draw of this robot?

I've build this arm (with a little modification, which i also posted as remix on thingiverse)
For the steering I've decided to write some own code to control the arm from Arduino, and there it is, I called it a project Orrorin, and uploaded to GitHub
And some of the tests from EEZYbotARM itself: https://www.youtube.com/watch?v=zA0Yn5y0k6U

I have assembled and working. The SG90 servo is a little tricky. I've stripped gears on 2. Seem to have a 180 deg range of motion. Going past too often does bad things. Not too familiar with servos, any tips?

I know many are using the Arduino to control, thought I would try something a little different. I used a Raspberry Pi with a AdaFruit servo hat to handle power and pgio. All controlled with a Python class. The sample code was very basic but this got me started. The sample code is Python 2 but someone converted to Python 3 as well.

Hey, are all files to construct? Some guidance on how to put together? Thank email: lukfotr@gmail.com

What can I use to control it

Where would you recommend purchasing the parts from online?

I bought most parts from Amazon. Most of the screws from a local hardware store. May vendors on Amazon are selling screws on bulk. Unless you want stock for future projects.

How much could it lift with the servos used? Anyone knows?
And have you got an idea using, high torque metal servos (~16kg) would increas that or would this be limited by the structure?
Thanks in advance.

Can you control it with Marlin?

what do i need to control it? I'm making one for a science fair.

Very nice design!

Can you give some idea of the payload weight, please?

Hi there, thanks a lot for the design.
I am still in the building phase but I saw the picker EBAmk2_016_claw_gear_drive.STL as you propose it, is easy to interfere with the 2 fingers when they go back to close position. They hardly go beneath the gear in my case. So I preferred to design a new gear that is half thick of yours on the dent side but same thickness on the axis. I don't know how to attach this in the comment so if you or someone need it, I can provide the STL file.

A few suggestions:

1) The area for the servo in the mainbase is too tight when the servo has wiring exiting from the side of the servo (as most do). I had to cut out a vertical half cylinder hole in the inside wall to allow for the wiring joint.
2) Please rename the straight links to describe placement. I mistakenly put the longer one on the bottom (shoulder to elbow) and the shorter at top (elbow to claw), when it should be the other way to make the claw parallel to ground.
3) It could be just my print (like extrusion multiplier), but I could not fit M3 nuts into the holes in the mainbase.
4) Maybe cut a small hole on bottom of mainbase for its servo wiring to exit.


I found an easier way -- just unscrew the four screws on the bottom of the servo, then bend back the wires and place it in and re-screw.

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

How much load does it can pick and hold

Comments deleted.

where can I find the program (software) to control it

where can I find the program (software) to control it

Comments deleted.

Where do I find the downloadable software to make this robotic arm work?

Where do I find the downloadable software to make this robotic arm work?

Comments deleted.

Hi there! Can't wait to make this awesome project. On your website, you list that only two M3 screws/nuts are needed, however the step-by-step instructions list far more than that. Could some of these be M4 instead? Any clarification would be helpful. Thank you!

Hola, tengo una consulta, me sabrían decir cuanto tiempo aprox demora la impresión en la impresora. Muchas Gracias Saludos desde Uruguay

Hola, tengo una consulta, me sabrían decir cuanto tiempo aprox demora la impresión en la impresora. Muchas Gracias Saludos desde Uruguay

I have a problem with the mainbase.STL.
The part is printed differently?
To see here:
Can someone help me please?

Comments deleted.

When you say "n.3 955 or 946 servo " that means we need 3 of that type of motor (https://www.amazon.com/SMAKN%C2%AE-MG946R-Torque-Digital-Helicopter/dp/B00H9624RA) ?

Yes, you need 3 955 or 946 servos

Comments deleted.

Where can I see all the assembly instructions?

this is so beautiful, man! i love the organic shape. would be nice if the base would also be a bit rounded.

You're right, I also do not like so much it's shape, but I want to finish it and I was a little tired, so I make it in a hurry.
But you can change it by your own and make a remix, I made available the source CAD files on Onshape: https://goo.gl/ACnRhT
If I get time for sure I'll follow your suggestion and I'll made a better rounded model

Can this arm lift an object of 1/2kgs?

I answered to talktosanjay3 previous comment

Can this arm lift an object of 1.5kgs? What would be the maximum weight this can lift?
Awesome Design BTW :)

I do not made calculation starting from the torque of servos, but also I have some doubts tha the whole structure can bear that weight
Months ago I start to design an Mk3 that uses nema 17 servos that for sure it is near to this payload, but for now is in standby ... first I have to finish my delta printer development

update 10/11/16
I made available the source CAD files on my Onshape account : https://goo.gl/ACnRhT
You can copy or export files !!!!

let me know if it works !

Any chance I could get the Cad files

how long is it's reach?

horizontal reach with original claw 340 mm

Hi daGHIZmo,
this one is made by me.

But I have question
As the photo, the servo arm is not fit at your design.
Could I know how do you solve this problem?(The black servo arm is attached when I bought the MG946R servo.)

Look between the remixes, I ran into the same problem and created the arms with a new cutout.

Hi daGHIZmo, I enjoy your designs, you do great work. I would love to see a rotational head for the gripper. I would try to design one myself but it's way beyond my capabilities. Perhaps you could consider it. Many thanks.

Hi, can you enter the other steps of the robotic arm because i have some difficulties with the assembly?

Hi, First of all Gz for your great work, your desings is on my top 10 first prints after i learn to use my printer, but i am very new to 3d printing and in roboting and i have that silly question. Do you think that i will able to use this arm with an arcade joystick or something like that..?

Hi, I would like to built this arm for use with a chess board so I can use it with a real physical chess board when playing opponents online. Would you think this arm could lift and move the chess peaces or would it be clumsy and knock everything over ruining the game?

It would depend on the weight of your chess pieces, But Yes I think it could manage the weight of medium sized plastic pieces. The problem I see initially is finding an easy way to grab the piece. You might have to redesign the grabber with some foam so it can form itself to each individual piece. The second challenge would be to make sure the arm can easily reach all positions on the board. I love the idea and really hope to see videos when you finish! Just so you know, my only qualifications on telling you this is working with the one I have built I have only had it a few days but I have learned a lot about its functionality over that time because I am working on a similar project :)

How much force is this able to apply? Would it be able to remove a part on a 3D printed bed for example, some of the parts are stuck on the bed quite firmly.

Hi, quick question, is it possible to use 1 servo on the arm instead of the 2 shown on the picture.I get that you need 1 servo for the base, but I'm trying to make this on a budget and I dont see the necessity of 2 servos for the arm

The first Servo is for the lower Arm-Movement and the scond for the upper-Arm. So I guess you need both.

inverse and forward kinematics are available in Robot Overlord. I just added uArm support. Add yours as well? Could help make this arm more useful by making it more easily programmable.

very clean design, nice!

hello, uses 3 servo 995? another servo which you can use? because in my country the 995 or 946 are very expensive. The aim is for fun, I do not need to have much strength, single movement. I thank you very much charm your work!

The assembly directions need to be completed on the website. Main base STL has errors and needed to be repaired. I am finding that 50% fill and .3 is better. Waiting for the electronics and specific screws to arrive. I am developing against the Arduino platform with my students and I will post any sketches as they occur. Can you please post pictures from multiple angles? or (one that can be rotated in 3d). I am using the robot to teach an introduction to programming classes. Thank you for your work.

Veja meu teste de funcionamento:

Veja minha impressão e esquema de ligação com o Arduino:


Thank Yoiu for the quality of the parts design.

I love your work. Is there any chance of getting hold of all the files in step format? My solidworks doesn't want to import the files other than graphics bodies and I would like to use this as a basis to teaching my son some 3d modelling. I could start him from scratch but I wanted to use something that he can see the end result and is inspired by then show him how it is built up in the software.

whats the maximum gripper distance between the two "fingers?"
i ask because i plan to use this for a automated miniature "3D printer factory"

Could you teach how to assembly n°25 Ø6 mm ball spheres
n°1 606zz bearing?
How about upload instructions to instructable.com?

Thank you a lot

6mm Airsoft pellets

I do not have so much time so is still under construction


Awesome project. My question is where do you find the screws you used in here?

Thank you.

Thanks for your design.I printed all parts, i have Mg995 servo motors, do i use them ? why do you chose 955 or 946 ?


sorry it was a mistake, I wrote 955 instead of 995.
Anyway it is not so important they have the same dimensions, only differences are about torque.
946 has a max torque (6V) of 13,5kg.cm, 995 11kg.cm and 955 8,5kg.cm



Can you help me ? In the zip files, has two types of file "EBAmk2_006_horarm__".

Which file I need to use ?


I provide two models of the horizontal arm. One has extended surface on the base to help avoiding detachment from the bed if you use like me ABS

Im going to try and print one of these later this month.

Quick question though; are the files in mm, cm or in? Im guessing mm, but wanted to make sure.

What kind of power supply do u use it for the proyect

do i need to keep conected the pololu with the pc? or can i load a program in it to use it as an arduino?

you can load it on the board and make it works disconnected. https://www.pololu.com/docs/pdf/0J40/maestro.pdf page 28

Hi, where is the threaded rod needed?

on both axis of mainarm 002

oh sorry you mean nuts, I thought you meant an actual threaded rod, sorry my bad


Any details for M6 screws?

M4 x 62mm long threated rod , Can I use M4 x 60mm solid rod instead?

M6x25, M4x60 ok

Complimenti ... molto bello .. si notano i movimenti più fluidi ;)

sicuramente i servo più performanti aiutano. Comunque ho scandagliatoil web per evitare il più possibile il jittering, shaking, spikes ecc... e di materiale se ne trova parecchio. Ho quindi sommato tutte le soluzioni hardware possibili quali: condensatori, anelli di ferrite twistare i fili ma pare che il risultato migliore si ottiene collegando un pin ground di arduino con il negativo dell'alimentazione dei servo. Non ho ancora provato dello soluzioni a livello di firmware però.

Great design! about 90% complete on printing mine

Looks great! Movement seems a lot smoother than the MK1. To clarify, you're using 1x 9gram servo on the gripper, and 3x standard size servos for the arm movement?

Excellent, thanks! I posted this question on your Instructables as well - do you plan to have an assembly guide for the Mk2? I'm sure I can get it close just by following your BOM and pictures here, but additional details would be helpful.

for sure I'll have to find time to make a detailed instruction of assembly. But I do not have one available now. Anyway I added a section view of the vertical axis that can help

This is awesome! What did you design it in?