Whoah!, what happened here?!
This is the work for a vacuum cleaner, to bad it did eat the part right above as well…:p
A little time ago I made a robotic arm, without the gripper. So last week I draw a gripper that is compatible with a mini servo, I made two versions because I had to chose between two kinds of gears, straight and rounded. Because I first finished the straight gears version I milled this one first, but since there was a little play between the two gears I also made the second one, the one with the rounded gears. I was surprised because it only took me about 2 hours to make one! The gripper with the rounded gears has much less play so thats a good sign. The gripper came out quite nice, here below are some pictures:
All the part milled out, the rounded gears look really nice, without much play!
The assembly of the hand, and the 2 hands I made.
Here’s a close-up of the little screws I used, there 2.0 x 10mm:
A close-up of the hand with some nice foam on it for extra grip.
Here’s how the mini-servo is connected with the gripper:
Here’s a video of the second gripper, it runs really nice!
Now my gripper and the arm itself is finished the mechanical part is actually finished, so I only have to make the electronics for it! Finely some progress!
A picture of the total arm:
Here’s how the arm moves, with a remote:
I already made some progress for the electronics, since I’m planning on using an Arduino to control the robot I made a shield just for connecting the servo’s with feedback to the Arduino.
On the right is the shield I made:
Testing the shield with some servo’s:
The schematic actually is really simple, it just gives the signals to the Arduino and backwards. There is also a female header for an infrared receiver and some female headers for power supply and 4 connections to the remaining (unused) Arduino I/O pins. So it is possible to connect another switch or sensor.
Here is how the PCB came out, the library I used had a bug in it because the distance between the headers was exactly one headerpin to close! To overcome this problem I bent the header pins to fit into the Arduino female headers. Maybe I make a new one with some more switches, but for now it is only to test the whole arm. For testing the robotic arm with the Arduino I have to wait for cables which I ordered to extension the existing ones. Also the cable has a 4th female header pin which gives the Arduino the analog voltage from the servo (which is later used for position feedback).
Here below are some more pictures of the whole arm, and a little video of the whole arm in action. Last week I had vacation so I milled another arm, just because it is possible 
I’m planning on making another few arms from some nice plastic like PVC or something and mill them on a real EMCO CNC milling machine at school, but the arm I have works perfectly so far and I already have two of them.
I started to post my things on thingiverse.com, so you can download the .stl files from there:
The standard servo gripper: (not for this robotic arm)
http://www.thingiverse.com/thing:2414
The mini servo gripper:
http://www.thingiverse.com/thing:2415
The arm:
http://www.thingiverse.com/thing:2433
I hope you like it, let me know if you made one
Update: Here’s the follow up post:
http://jjshortcut.wordpress.com/2010/08/17/multiply-the-robotic-arm-and-electronics/
Nice work! did the hand always fall on flor when you turn of electricity?
Actually it is to heavy to carry it’s own weight, so I used springs to compensate the weight.
Ok. I do thing like that what you done
Hey, this servo arm looks PERFECT for a project im looking at making, so i was wondering where you bought your servos, cheapest i saw for all servos was about $42 or so. If i do end up building ill be sure to let you know.
Sir I am a final year Electronics student pursuing my degree of B.E. I have planned to make a robotic arm for my final year project.
I saw your work and was truly amazed.I know you must be very busy with your work.But it would be a favour if you can guide me as in how to go on sequentially to implement this project.I have searched a lot about the project but too many ideas and too many links are doing nothing more than confusing me rather.
So I’ld really appreaciate if you can take out some of your precious time to guide me.
Thank you.
( I know I’m asking for too much at this point of time.But I’m very much interested in robotics and am looking forward to do muchmore in robotics.It would be very difficult at this level to understand all aspects but i want to try and achieve it.)
I’m willing to help you, but you have to tell me on which subject you need help. Soon I will be posting the electronics of the robotic arm.
As I told Sir I’m making a robotic arm for my final year project.Wat I’m told by my Profs. is tat I’ll have 2 design d whole arm myself.So I’ll have 2 take care of all d load handling capabilites & freedom of movement which seems a bit tricky at dis point of time since I haven’t started my work yet.U said U’ve used 4mm thick hardwood.Tats wat I wanna know d material used by U,d ratings of d servos(type,rpm,torque),d weight-lifting capacity of ur arm.Also its freedom of movement since servos r used.Also if u can tell me places wer I should take care wer u must’ve faced few difficulties.
The only reason I’m being too cautious is tat I don’t want 2 waste much time in places wer ur guidance can help
Hi, I’m not sure I can help you on all these topics, but I will give it a try.
The servo’s I use are the cheapest ones I could find (Conrad: http://www2.conrad.nl/goto.php?artikel=233751 (you can find the torque here), but choosing these servo’s results in the fact I have to use a spring for compensate the mass of the arm. For the weight lifting capacity I’m not sure, I’m still working on the software and electronics and have not tried much lifting yet. You can try to calculate it, if you know the servo’s and materials you want to use. All the servo’s can be set at almost 180 degrees of freedom (depending on the servo specs). For difficulties the most important thing (I think) is to make a proper and small design for a gripper which closes parallel. I did looked a lot at other existing arms, especially the lynxs 6. Maybe it is a good idea to first make a list of what the arm has to do: degrees of freedom, velocity, lifting capacity etc.
I hope this helps you a bit!
What is the material used for arm and gripper
Hardboard 4mm or mdf 4mm
Quick question, the bolts you used on the gripper, maybe you have a link with a closer view of them? Or maybe a place where to order them?
Hi I updated the article with a new picture, with a close-up of the screws I use. (http://jjshortcut.files.wordpress.com/2010/04/img_5461-1024×7681.jpg)
Hi there,
I have built the grippers and all is OK apart from the gears which I am having trouble with as I have cut them out of 4mm PCB material and filing them to suit is a real pig of a job by hand , Have you any spares I could buy off you from the NC machine. For other people building this print the drawing of the parts then use the photocopier enlarge feature to match the size to the servo motors. I am using PICAXE 8 to drive them.
Hi,
I saw another method, if you don’t have a milling machine, maybe you can use the method discribed at http://www.diniro.net/fabbblog/2008/03/diy-how-to-build-a-robotic-arm.html
For the geared parts e-mail me: mail
For people put off by complex software to drive the servos try
http://www.rev-ed.co.uk/images/full/AXE024.jpg This will allow a beginner to write code in basic to drive the gripper arm. The board will drive three servos and there are more complex chips to expand this to eight. If you download the data sheet in pdf and copy and paste the examble code and load it into the chip via serial leadand software provided then that code will allow you to set up the gripper using two servos with no modification to the software. You will need to match up the position of the servos to suit.
can you plz giv me a snap shot of the back side of the gripper where the servo is attached with it, so that i might get an idea that how exactly i need to attach it with gripper
hi, what sized screws did you use to attach the servo horn to the structure?
Hi, I used 2.0 x 10mm screws, you can see them in one of the pictures.
hmm ok. i measured the holes of mine but it measures around 1mm+ about 1.4sorta. did you enlarge yours?
I drilled the holes with 1.6 I think, and I used the 2.0mm screws. But the size of the hole depends on the size of your screws.
hi, may i take alook at your power supply? i most prob will be using a modified PSU to use the 5v and solder it somewhere to drive the servos.
I first used 4 AA battery’s, but now I use just a regular power supply of 5V 3Amps. You need quite a big buffer for driving all the servo’s at once.
ah yea i would have thought so. did you get a regulated lab supply or? my servos are hs 422, around 700mA to 800mA each :O five would take up 4amps..
Hey nice arm..
I m really very much confused
do i need to program the servo(gripper one) in a loop to get a grip or it will work without writing the code in loop ?..
i know thats a stupid question but i would like your help..
Thankss.
I use an Arduino for controlling the servo’s, and if I control a servo with it, a PWM signal is created to control the servo and it continues the PWM signal until it is changed (or if you cut the power). So the Arduino creates a sort of loop to control the servo, so you don’t have to take care of it.
how will it work for picaxe 28X1 ? …hope you know some basics about picaxe..
and yeah thnx for your informative repy..
Sorry I actually don’t know anything about the picaxe, but I think it will not be that hard to control a servo.
actually the main problem with me is that..am making a robot which has a arm on its base to pick up cans/bottles..etc..so in case of programming it..i will have to make a loop which is called the “main loop” of the code…so if i make a “main loop” ..then it wouldn’t be possible to put the servo code in another loop in the same program…
hope u understand..
I’m not exactly sure about what you mean, but I think it works with interrupts at a certain time interval. I can’t help you on the programming of a picaxe, but I think there must be enough tutorials about controlling a servo.
sure…anyway thnx..
Nice robot… What is the weight of this whole robot..? And how much weight it can lift..
Hi,
The weight of the whole robot including the servo’s is about 487 gram. For the lifting I actually don’t know, depends on het voltage at the servo’s and the servo’s itself. I think it might be something like 100 gram.
hi. my final year project is to built a robotic arm to lift a tennis ball. i am wondering if u could help me in the design of the gripper. could u send me the design for the gripper? tq.
You can find drawings on Thingiverse, the links are at the end of this post.
hi there. its hard to find a cnc machine around my area. i am wondering if u could help me to make the gripper without the servo. maybe i can pay u?
Maybe you can make the parts like the method described here: http://www.diniro.net/fabbblog/2008/03/diy-how-to-build-a-robotic-arm.html
make another one!
Is it possible to get the drawing in a 1-1 scale pdf?
I can’t export the files to pdf directly, but I’m sure there is a way to convert the drawings. I think Inkscape can convert the dxf files to pdf.
hi…i m a diploma student and preparing a pick and place robot as my final year project. your idea is a innovative and helped me to create my design for a robotic arm. as a 3rd year mechanical student i’m facing some problems while designing it further. i wanted to know the type of motors you used with their specifications. would be waiting for your reply. and i must say a good project made by you….
Hi, you can find the specification of the motors used in this arm at conrad.nl order numbers are 230500 – 89 and 230500 – 89.
hii frnz.. can you please send me that documentation
What documentation do you need?
Hello,
I am currently working on my own robot, and one of it’s components is robotic arm equipped with gripper. I find your solution very attractive, and would like to use it in my solution(Of course if you don’t mind)
Is it possible for you to send me schematics of mini gripper like those depicted here:
http://thingiverse-production.s3.amazonaws.com/renders/81/61/f0/3d/53/total_sheet_gripper_rounded_gears_display_medium.jpg
but in some sort of CAD format? I could then use it in CNC like tool. Or maybe tell me how did you
Also what are the dimensions of mini servo that you used? Since servo is attached to one of the elements(shape and screw-holes are clearly visible) maybe i just need to rescale your project to my servo’s dimensions which are 23×12,2×29 mm.
I am looking forward to hearing from you,
Regards Arek
Hi,
For drawings check out my Thingiverse:
The whole arm:
http://www.thingiverse.com/thing:2433
and the gripper:
http://www.thingiverse.com/thing:2415
There are .stl files and a sheet with the whole robotic arm in .dxf format.
For info about the servo’s please check out the Thingiverse object, it has all the information about the type of servo’s.
Thx for quick answer! I didn’t notice the dxf file when i was browsing thingiverse.
But i don’t fully understand that sentnce:
“For info about the servo’s please check out the Thingiverse object, it has all the information about the type of servo’s.”
Do you mean by that those stl files? I’m not familiar with that format. Is there any easy way just to rescale whole project to size that would match my servo?
Thanks in advance,
Regards Arek
Hi,
The servo’s I used are:
TopLine mini-servo ES-05 JR
TopLine standaard servo RS 2 J/R
Check for the dimensions of those. If there is a difference, which I doubt, you can rescale the whole drawing sheet (.dxf file) to your servo’s but It’s better to just rescale the servo hole in stead of the whole sheet because the screws won’t fit anymore.
.stl files are a simple universal format for 3d objects. Thingiverse is 3d-printed oriented and a 3d printer can handle stl files, but for milling a .dxf file is as good as because almost everything is just 2d.
Thank you for answers:)
Hey,
I’ve been researching for a long time on building a cheap robotic arm and I must say, this is one of the best I’ve seen.
I’m planning to go ahead and try to make one of my own (might take time due to lack of proper resources here) but the only thing that I’m doubtful about is the programming part. First part of my project is related to manually controlling the arm with the help of an Arduino and Processing/PS Remote. I was just wondering if you could suggest some reference material which would help me program it. I don’t have much programming experience,but I hope to change that with this. Thanks!
Hi,
Programming the robotic arm is very simple with an Arduino, you just control the servo’s with the servo function which is very nicely described at the arduino site. If you open a example of the servo in the Arduino software it is realy simple. So just look at the Arduino site and examples provided in the software.
Oh thanks for the reply. Will surely check it out. Although, I’m trying out a different gripper design than yours. Don’t really have a CNC milling machine nearby!
Thanks again.
Hello again,
An Arduino can run 6-7 servos at once. I was wondering if a servo controller for this project is required or not?? If it is then can you suggest me one which I can buy? The ones I found online are not custom made for an Arduino, as in, directly plug it into an arduino and control the motors. Can you help me out with this??
Hi,
Make sure you check out http://jjshortcut.wordpress.com/2010/08/17/multiply-the-robotic-arm-and-electronics/, there I described the electronics I used, an Arduino with shield. The shield is not much more than connections from the pins of the Arduino to the servo’s. You do not need a servo controller because the arduino is controlling the servo’s. You just buy a standard servo motor and connect it (directly) to the Arduino. In fact that’s where I made the shield PCB for (with some fancy stuff like leds etc.)
Hey,
Well I am almost finished with my arm chassis… Is it possible for you to mail me the pics of the arm which show the other side of the arm (opposite to the servo shaft)? I wanted to check how you have put up the bearings??
Hi,
I used a plastic part as which looks like this for the bearing. I used double sided tape for connecting it to the back of the servo check http://thingiverse-production.s3.amazonaws.com/renders/28/ef/01/fc/30/IMG_4278_%5B800x600_display_medium.jpg
You see on the picture the part on the back of the servo.
hello
great work…
So if you have your DFX file is it enough that I import them into Mach3 and use like 1.5 mm tool or do I need some additional adjustments???
thx in advance
Hi
You can cut the part using a 1.5mm I guess, the parts are at the right size so..
hello
i figure out that i need to make a diferent toolpaths in artcam and then export them to mach3, and 1.5mm just do fine.
hello
great work..
is there any servo arm that using a digital gate ? because now in my school, i work on the science fair and i want to make a servo arm, but i totally don’t understand about programming the robot, just called me newbie or beginner. And how i get the remote control for controlling the robot ? i am confuse right now, because my school only give a 12 bucks to make it. low budget.
sorry if my language was bad, i am not an america :p
thanks a lot
I’m not sure what you mean, but making the robot arm with only 12 bucks can’t be done. The servo motors only are priced at 5 to 6 dollar each..
hello sir you are doing a great job …I want the circut of this gripper it will be really an honar for me… thankx
regards
Ahsan
department of mechatronics engineering
University of engineering & technology Taxila chakwal campus
All the drawings are on thiniverse and the pcb is on my blog.
I am a bit weak in programing kindly i want a code too
first test
great stuf thx J-J..
Hello!
). Thank you in advice!
Nice project! But I have a question – which type of servo you’re using? Because, in every micro servo the position of the mounting screws are different (actually, I mean that the length between the mounting screws is different
Best regards,
Bobby
Hi,
On the thingiverse site are the drawings of the arm with, of course the dimensions. He used type of servo is also descibed there.
Hello and happy new year!!
Unfortunately the servos you used are too expensive for me and the shipment to Romania is hard. I found some other ones in China via eBay but I don’t know if they will fit.
Can you please provide some compatible alternatives? I already made the arm I don’t want to get any servos and risk that they will not fit.
Thank you
The robot arm is compattible with the servos I used, but I think most other standard servos will fit as well. You just have to check the dimensions…
41x20mm
hello. please help me. I have a doubt. how is the other corner of arm is attached to servo motor. one side is shaft fixed and other side what they fixed for the wooden arm
please help me. I have a doubt. how is the other corner of arm is attached to servo motor. one side is shaft fixed and other side what they fixed for the wooden arm
I used a plastic part as which looks like this (http://thingiverse-production.s3.amazonaws.com/renders/15/91/ce/ba/df/bearingwrist_display_medium.jpg) for the bearing. I used double sided tape for connecting it to the back of the servo check http://thingiverse-production.s3.amazonaws.com/renders/28/ef/01/fc/30/IMG_4278_%5B800x600_display_medium.jpg
You see on the picture the part on the back of the servo.
The links are broken. Do you have any updated links?
hey i have planned to make this arm…… so plz help me in doing the same…….. i hope u will……
hi,
At present am doing my final year project which requires a pick n place bot. When i searched the web i stumbled across this work of yours. I intend to use this design of yours for designing the arm of my bot (limited 2 D.O.F.).
It would be of great help to me if you could give me the exact dimensions of your work.
Thanks in advance.
P.S.: I am an electronic student & hence i’m not acquainted with the cad tool.
The exact dimensions of the objects in the image “IMG_4262[800x600]” would suffice, because i intend to design the gripper alone..
Thanks in advance..
Hi,
Check thingiverse, there are the drawings of the gripper also.
Nice work !!!! please can you send me the programe arduino to commande this robotic arm and the circuit schematics.
Thanks.
it is really easy to control servo try matrix flowcode
ok, thanks, but i what to do with a PIC18f2550 and USB Connection.
I want to control manually and with the computer.
well you could use a lot cheaper mcu and bluetooth modul with spp protocol.
http://www.youtube.com/user/grunftz?feature=mhee
Looks very cool! Do you already have a complete arm? Looking forward to see it controlled by an Android phone!
soon…… today i done some cuting on my CNC at work, wil be fully controlled via android phone, but that is a really easy, app is build with appinventor….
Sadly I do not own an Android phone.. but what bluetooth module did you use? Good luck on the build!
the cheapes one from dealextrem
http://www.dealextreme.com/p/wireless-bluetooth-rs232-ttl-transceiver-module-80711
O yeah I already used one of those for making my 3d printer print wireless. How did you connect them to your phone?
with andorid app, just need to turn on bluetooth on the phone and paired with the module, then with the app from phone make a connection and scan the acelerommeter data and make some ” if-then” statement, basically it’s all serial communication….
Oke it’s just serial communication, I did not know this could be done by a phone app. Good to know
on my HTC wildfire original firmware (froyo 2.2) SPP refuse to work so i had to route my phone and install custom rom CyanogenMod 7.1 gingerbread 2.3.7, and since then everything works just fine, but i lose a warranty for phone
I mean root my phone not rout
, fast typing……
I myself do not have much experience with PIC microcontrollers so I can’t help you on this..
Yes, i have a complete arm. I’m working now on the firmware (PIC18f2550) and software (VS C#).
when finished I’ll post some pictures of my servo arm.
I’ve just subscribed to your sites feed, thanks a bunch for all the hard work you put into the site.
Hi!
This is my arm: http://imgur.com/KIqbj
Hope you like it.
Super cool! nice to see you finished it, I definitely like it
How did you make the “bearings” at the back of the servo’s?
I’ve cut 1cm cilinder from a orange plastic rod that dad used for fishing and superglued it in place. It’s pretty solid.
The elbow servo it’s kinda weak. I’ll need to find a spring or some rubber bands to help it lift weight.
I’ll keep you posted.
helloo
here is my frist hardware test with C# app in early development stage…
and some of my students hardcoded first test
That looks very neat, I’m looking forward how things are developing! Will the program be released? Or open source?
Sharing is caring….:)
everything is going to be a open source of course i work as a teacher so it is my obligation
….when me and my students make a bet version you wil be first to known!!!!
all the best, greeatings from Bosnia
Nice! I’m looking forward to see it
Very nice work! Please post follow ups. What MCU are you using ?
I also wanted to make it out of acrylic/plexi but the costs were to high for my budget.
Best wishes from Romania.
There’s a follow up post, check at the bottom of the page
There’s a bit code as well but not much.
Sir, how can i contact you personal? I have some questions to ask you.
Please do this in the comments since others would have advantage of it
Can you please send me the dimensions of your robot arm such as the diameter of the base and the length of the lower arm. I’d greatly appreciate if you did because the 2D design program I use changes the size of the sketch.
Hi, for a reference you can take the holes in the arm, those are 3mm (the most used drilling holes). For example the hole in the bottom right corner are 3mm.
jjshortcut is right but I have a suggestion. I had a lot of trouble finding 3mm screws. First look at your store for 3mm. If you can’t find them, chose 3.5mm ones because they are easier to find. The whole arm will be a bit bigger but the servos(if you choose the ones used by jjschortcut) will do the job just fine. Another advice, try to minimize the number of screws used to keep the whole assembly light. 2 screws for each servo is enough.
Update from my project:
I managed to hook up all the stuff, the arm is working just fine, although I didn’t hack into the servos to do an analog read like jjshortcut did. I will post in the following week the code for the arduino and a python(pygtk GTK2 more precise) written program to control the servos via serial port. Note that the program works only under linux. I used the one of the 3 buttons to switch from IR control or serial control(or both), and the other 2 to make something automatically.
This is my collage final project. I will post the written part as well, but it will be in Romanian so I don’t know how much it will be usable for this open project. Who knows.
Regards
Could you please tell me the diameter of the base, thats what I’m having trouble with.
The base, which has the mounting holes, is 95mm, without the mounting holes pieces so just the diameter of the round circle of the part.
Thank you, greatly appreciated, you could check out my blog at opensourceroboticarm.blogspot.co.uk
What servos did you use for everything except the gripper an wrist?
check the thingiverse site, I mentioned the type there, there standard and mini servo’s
thanks
hallo janjaap
ik heb een vraagje
is het ook mogelijk om de robotarm manueel te besturen?
mvg Steven
Je kunt de robotarm aansturen als je een afstandsbediening en ontvanger voor modelbouwservos hebt ja
zo’n f14 is de controller?
Dat is in het filmpje de afstandsbediening ja, futaba F14 afstandsbediening
you know the bars that run in-between the two sides of the lower arm, could you tell me what they are called, I’d like to buy some. I tried using other methods, they didn’t look as nice.
Hey, the’re called threaded (Hexagonal) spacers, M3 is what I used.
Hello again
I got back to contribute.
Here is my arduino sketch and a webpage to control the servos. It uses the php_serial_class..
https://github.com/adrianrly/robotic-arm-ir-php
Awesome, cool!
Very nice and neat gripper… How do you calculate the stress needed to grip an item?
Dude.. can i ask what type specific type of hardboard you are using.. we’re having a quite problem using plexi glass for the gripper. Thanks by the way,, this has been very helpful.
I’ve just used normal hardboard 4mm, this is kind of MDF but with a lacker layer on it…
thanks dude
great help.
hello. if you dont mind sir. can you give some idea? i need other application of robot arm gripper for my thesis. thanks! More power to you.
Please send to my email the pattern of the original size robotic arm(inch).i want to make too
Please check the thingiverse site, this has all the drawings.
i want to make a best project for my semester
as one of my project got leaked and the idea was submitted by another group i was rejected later
now i have only one week for dead line of another project
can u help me make me or suggest me to prepare a best project
Hey hai.I am doing a similar project 4 my final year project. I am not able to understand how u connected the servo motors.Please.if possible,put up a tutorial so as to how the motors are connected.Please reply to my mail id so that I can ask 4 ur help when im in need .my email id is araditya93@gmail.com
Also please guide me regarding ,how the servo motors are attached at the shafts of the arm
and also guide me so as to how springs are used to balance the arm when no external power is being supplied.
awesome man!
I love it. keep up the good work
Dear JJ,
I am a Phd student working on intelligent automation at Cranfield University, UK. I wanted a 6-DOF robot arm for my research and figured out thanks to our detailed blog that I can build one cheaply and quickly. I am glad I did it and learnt a lot during the process. I will cite your blog wherever I publish my work using the robot arm and keep you updated. Please let me know if there are any preferences you may have on providing citations to your work.
Thanks for this wonderful work!
Kind Regards,
Vinayak
sir can u give me the dimension of each part of a robotic arm gripper……
You can download the drawings of the robotarm on which you can find the dimensions
pls send on my mail id shorya115@gmail.com
but sir i didnt find the right link pls send the link
sir plzz help me quickly
plz
Here you can download the files
http://www.thingiverse.com/thing:2433
Mr. admin please post the size detail of arms and mechanical parts… and which servo you are using
I just used regular size servo’s, TopLine standard servo RS 2 J/R and TopLine mini-servo ES-05 JR.
Hi JJ,
Really cool arm and also the other stuff that you do (CNC, etc’) are pretty awesome !
I’m currently trying to clone your arm for being a part of my final project at school.
I’m wondering which bolts and nuts to buy and how many,
i read in your posts that you used M3 bolts and different spacers.
do you maybe have a list of all the bolts and nuts that you used and how many from each type ?
it can make things easier since i’m using the same parts as you did…