Well I finally did it. I finally pulled the trigger and started to build a 5/6 axis robotic arm. This is an ongoing project so please check back from time to time to look at the progress and offer any ideas you might have who knows I just might include the changes. I have alot done so far. I will try to make this a step by step. If any of you need clarification or just more info on how i did that or where do i find that bit of software or that part etc. just drop me an email. So with that said lets get started. Please forgive any grammatical or spelling errors I am in a rush to finish this project please let me know if you see any.
If I win the Laser cutting machine. I will use it to produce more robots. After all even robots need skin. Not to mention all the projects I can make with such an awsome too. I use a larger one like it before and it was amazing the speed and quality of the finished parts.
So to begin with any robotic project no mater how complex you must plan, plan, plan, and then finally figure out or layout how you will go about it.. or "PLAN"...
Use your head when building anything. Use safety glasses when running mills drills or any power tool Your eye's are just little water balloons and can pop like a grape so protect them. I don't have time to create an instructable on how to replace your eye.
You're fingers hands and other appendages will lose any battle you engage in with a cnc, lathe or most power tools. Don't take them for granted. I have 30 years experience with machine tools and the building of robots I will try to make this easy. If you have a good design you can send out the drawings to have the major part fabricated fairly cheaply. If you don't know how to use a tool then learn, take a class, ask me or learn the trade. These types of machines have a mind of their own and must be respected, Safety first.
Now That the safety brief is out of the way lets get on with the show.
This picture is my last concept before i began. I created this layout with solidworks. that way i could test for any interference from moving parts in order to make sure they would all fit together just right. I also wanted to test for load bearing and lateral forces, as well as motor torque and loads. This information though not needed right away is a must for later on.
The mechanical layout is just a small piece of the design you must also consider all the programing that will be part of any robot you build especially a 6 axis robotic arm with inverse kenimetrics. More on that later. Once i had the basic layout I needed to make sure i cold afford the parts necessary to build this monster. I had to source the motors and find a supplier, as well as the gear/ drive train for each axis.
The motors i settled on were found on Ebay for 30.00 each. I bought 10 because i want to build more that one robot arm.
If I win the Laser cutting machine. I will use it to produce more robots. After all even robots need skin. Not to mention all the projects I can make with such an awsome too. I use a larger one like it before and it was amazing the speed and quality of the finished parts.
So to begin with any robotic project no mater how complex you must plan, plan, plan, and then finally figure out or layout how you will go about it.. or "PLAN"...
Use your head when building anything. Use safety glasses when running mills drills or any power tool Your eye's are just little water balloons and can pop like a grape so protect them. I don't have time to create an instructable on how to replace your eye.
You're fingers hands and other appendages will lose any battle you engage in with a cnc, lathe or most power tools. Don't take them for granted. I have 30 years experience with machine tools and the building of robots I will try to make this easy. If you have a good design you can send out the drawings to have the major part fabricated fairly cheaply. If you don't know how to use a tool then learn, take a class, ask me or learn the trade. These types of machines have a mind of their own and must be respected, Safety first.
Now That the safety brief is out of the way lets get on with the show.
This picture is my last concept before i began. I created this layout with solidworks. that way i could test for any interference from moving parts in order to make sure they would all fit together just right. I also wanted to test for load bearing and lateral forces, as well as motor torque and loads. This information though not needed right away is a must for later on.
The mechanical layout is just a small piece of the design you must also consider all the programing that will be part of any robot you build especially a 6 axis robotic arm with inverse kenimetrics. More on that later. Once i had the basic layout I needed to make sure i cold afford the parts necessary to build this monster. I had to source the motors and find a supplier, as well as the gear/ drive train for each axis.
The motors i settled on were found on Ebay for 30.00 each. I bought 10 because i want to build more that one robot arm.
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Signing UpStep 1: Motor and Gear Choice
This picture shows two of my motors with a controller. The motors as mention above were bought on ebay for 30.00 each. They are brushed DC motors and run on 60 volts peak. up to 8 amps. these are strong stable motors perfect for the job. A few things you need to be aware of when building any electrically powered device driven by motors. one is the voltage you plan on using this gets into available power sources. You have to be able to power your creation once you build it. I choose 60 volt dc because I could easily find a DC power supply for them, or if necessary build one myself. I will show you the power supply later on. You also need to consider the shaft size of the motor. This is important because you need to be able to find a suitable and low cost yet capable gear reduction system for the robot.
I chose to use a 10 to one reduction encapsulated in a planetary arrangement. this gives me great space savings as well as an efficient power out with good torque characteristics. These pictured were found on the internet and brand new cost me 150.00 apiece. Choose wisely when selecting your gear reduction or drive system. I made a mistake when i chose these units they should have been 30 to 1 not 10 to 1 as a result I will need to add a bellows system to help counteract the extra weight to avoid wearing out the motors and burning up the power supply. I will show you how I was able to fix this issue with very little effort though, sometimes you have to roll with the punches to get the job done. My solution was simple yet elegant and effective. I will install the Bellow system once I receive the parts i ordered should be here next week or so.
The last item you need to be aware of when picking a drive system is not only the motor and the transmission but the feedback system needs to be addressed. All robotic mobile systems need feedback otherwise they will not know where they are in relation to a known point, this is key to control of each axis. I have a 5000 count quadrature encoder on each axis this give me with the 10 to one gear reduction over 400000 counts per axis revolution, and as you may know the more resolution you have in your feedback loop the more accurate the robot is going to be. You can see the encoders mounted here in this pic they are located on the end of each motor with the grey cap. Renco makes these encoders.
I chose to use a 10 to one reduction encapsulated in a planetary arrangement. this gives me great space savings as well as an efficient power out with good torque characteristics. These pictured were found on the internet and brand new cost me 150.00 apiece. Choose wisely when selecting your gear reduction or drive system. I made a mistake when i chose these units they should have been 30 to 1 not 10 to 1 as a result I will need to add a bellows system to help counteract the extra weight to avoid wearing out the motors and burning up the power supply. I will show you how I was able to fix this issue with very little effort though, sometimes you have to roll with the punches to get the job done. My solution was simple yet elegant and effective. I will install the Bellow system once I receive the parts i ordered should be here next week or so.
The last item you need to be aware of when picking a drive system is not only the motor and the transmission but the feedback system needs to be addressed. All robotic mobile systems need feedback otherwise they will not know where they are in relation to a known point, this is key to control of each axis. I have a 5000 count quadrature encoder on each axis this give me with the 10 to one gear reduction over 400000 counts per axis revolution, and as you may know the more resolution you have in your feedback loop the more accurate the robot is going to be. You can see the encoders mounted here in this pic they are located on the end of each motor with the grey cap. Renco makes these encoders.
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ABSOLUTELY ! HAVE BEEN IN MANUFACTURING FOR 25 YEARS and
I can think of many uses for this, do you think this can drill change tool then tap
say up to 1/2 inch. sure would free up the cnc a whole lot, I would talk to the
robot from solidworks if possible
Oh ya and please vote for my robot arm to win the contest the button to vote is at the top of the page..
thanks
Warren
Not too long ago I Was where you are. Just took a positive attitude and a strong work ethic, Oh an no sleep...
Warren
you should post this on letsmakerobots.com
Nothing more to Say.. !!
You told about 7136 aluminium. Where do you got it from ? Is it possible to melt / cast this type of aluminium with a home furnace ?
Sorry if I´m dreaming toooo much.
And congrats for such a wonderfull work !
WWW.phantasm1.com
Ok, lets start with "for give" you have something in favor of giving!
You want "forgive".
Great instructable sort of out of the the do it yourself at home project but nevertheless very informative.
Ralph
fascinated to see what you do with this item. I'm a surgeon and I'm toying with the idea of building an artistic and anatomically accurate copy of the human hand and arm in brass, copper and bone ( beef - when bleached it's a great material to work with) .
Ideally, I'd like to motorize it and this seems to be what I've been looking for to do that, but I have to say that it's a big step up for me as my programming skills are rudimentary at best. Still, your exposition's really clear, so who knows.maybe I'll give it a go....
Well done sir.
your arm sound fascinating. send me the specs I will build it for you..
I will get to the errors you found i hope today.
please vote for my robot and tell your freinds about it. I need all the help I can get.
thanks
Warren
can you please post motor and gearbox part numbers?
btw. how is the robot arm behaving so far? it looks cool, and i like the fact that it can fold but will it be stiff enough when end effector encounters side load?
and what is the name of the software running on the PC and controlling the arm?
the software I am using is Servo Commander. written by Olly. at HVLABS check it out. also this software works via the controller this is important to understand. that the controller actually is the brains of the particular axis. it controls how the arm get to the commanded position and how it behaves. this is kind of like a neural network. the primary pc only issues the commands. I hope to move all the programing functions to the motor controllers. they more than have enough power to handle the job.
as far as programing. none is needed that is the beauty of the system. I build this to be easy enough for a 6th grader to drive and program. I will post further update with a video to show just what i mean in my next update.
in the mean time tell you friends to vote for this robot I really need that laser to help me in my work and robotics research.
please vote for my project to win.
Thanks for the kind words.
Will you have any more details on the programing of this arm?
Warren
Please, pretty please ... continue !
thanks for the comments please vote for my creation
Warren