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Topic: I am a newcomer, about to get an arduino starter kit, any tips for a robot? (Read 825 times) previous topic - next topic

rooarko

Hi guys I am a newcomer to arduino, microcontrollers etc.
I am going to buy an arduino starter kit soon, and I am wandering if any of you could give me some tips as my plan is a robotic arm.
Brief idea is servos, but i am wandering if there are any other useful ideas out there?
Plus could you give me some tips on what programming to use. (NEWCOMER tips).
Thanks guys.

zoomkat

You could get some servos and pots and make something like below. Lot of arduino controlled robotic arms on youtube.  Remember servos will require an external power supply.



http://www.hobbyking.com/hobbyking/store/__3743__HXT_6_9kg_39_2g_16sec_Twin_bearing_servo.html

http://www.ebay.com/itm/10pcs-10K-Ohm-B10K-Knurled-Shaft-Linear-Rotary-Taper-Potentiometer-/260985203825

http://www.youtube.com/watch?v=nYG19lhlA3c
Google forum search: Use Google Advanced Search and use Http://forum.arduino.cc/index in the "site or domain:" box.

tbradt

I'm a newcomer too, so take this for what it's worth.

My only real tip would be to break the project down into smaller projects and buy the parts for each part as you need them at first. You'll learn a lot as you do your first couple of small projects. If you're anything like me, ordering everything right at the start just means that you will end up having to buy a lot of it again because you got the wrong part the first go round, or you find something that suits the task better.

I have a lot of spare parts lying around because of that. They're fun to have, but as I learn more I'm getting better at finding the correct parts for a task.

rooarko

Thanks guys I will definatly take the tips foreward, they seem quite helpful in my situation.
BTW I'm not alone as I have a friend who IS quite handy with this stuff like I am. So we will figure things out. By the way Zoomkat I haven't checked out the link bit I will. And tbradt the tips for specifically looking for parts is a good idea as this project I have in mind will require plans like that!

cr0sh

One tip you might find useful is to mount all motors or actuators as close to the "base" of the robot arm as you can; essentially, the more mass you put out beyond the base, the more powerful each motor has to be as it gets closer to the base, and the more mass it has to move (and stop!) - leaving less mass for you to lift, as well as making it more difficult to be accurate.

You might do well to take a look at various other small hobbyist robot arms - and I am not talking about the current crop of servo-based arms (though certainly look at them for ideas!). Instead, take a look at this one:

http://teachmover.com/

The TeachMover is a classic industrial automation training arm that is still manufactured today (old ones are considered collectible and fairly expensive; new ones are without a doubt very expensive). They originally were designed to be connected via a serial (or sometimes parallel) interface to a home computer or PC - though likely nowadays they use a USB connection of some sort (?). If you do some research on them, you will notice that they use a series of stepper motors located in the base of the arm to control all of the end-effector movements...

Also - take a look at this site:

http://www.rhinorobotics.com/xr3_flyer.html

Again - Rhino manufactures a relatively "classic" arm for training purposes - notice the positioning of the motors (in this case, DC motors with integrated encoders, instead of steppers), as well as the chassis design (open elements to reduce the weight of the arm, while enabling high strength). Note, though, that they did position a motor for the gripper at the end of the arm.

Also - take a look at this arm:

http://www.senster.com/alex_zivanovic/armdroid/
http://theoldrobots.com/clone.html
http://www.anf.nildram.co.uk/beebcontrol/arms/armdroid/

The Armdroid was another one of those "classic" training robot arms - but in this case made in a slightly different fashion from the others to reduce its (comparative) cost significantly, compared to the previous examples. The greatest difference is that the Armdroid used pulleys and cables to route the motion to the joints - instead of the more expensive timing belts and toothed cogs (TeachMover) or chain and sprockets (Rhino). This did, however, cause these arms to fail more often when the cables broke. It's design, though, led to a whole host of "clone" Armdroids being manufactured - mostly in Europe and (at the time) the Eastern Bloc countries; if you happen to find one of these machines being sold, most likely the first thing you'll have to do is "restring" it to get it to work.

The nice thing about the Armdroid, though, is that given the diagrams and information available about it, it should be fairly easy to replicate, if you wanted to do so; the most difficult part would be replicating the differential "wrist" joint, which needs 45 degree bevel gears (an easy way to obtain such gears, though, is to tear down cheap right-angle grinders; many makes have such gears in them).

Finally - on the subject of hobbyist robotic arms - check out this page (if you don't read Spanish - use google translate; it works relatively well for the pages at this site):

https://sites.google.com/site/proyectosroboticos/

It might also do you well to examine how regular industrial robots have been constructed throughout the last 60 or so years; there have been many designs and such that you might be able to replicate (the current crop of industrial robots, though, tend to have integrated motors at the joints, which will be difficult to impossible to replicate - such motors are either coupled directly with the joint, or through a harmonic coupling drive to reduce speed and increase torque - all of which makes for a very accurate, though expensive arm). Check out this site for some history of such:

http://cyberneticzoo.com/

...as well as googling terms on "industrial robots" and "industrial automation" - and the like...
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

JB_AU

http://www.lynxmotion.com/p-395-ssc-32-servo-controller.aspx

Is a 32 channel servo controller, its an independent system that can be controlled with an arduino.
You can also get a usb clone version

http://www.aliexpress.com/item/32-Channel-Servo-Motor-Control-Driver-Board-for-Robot-Project-and-Chassis/882082427.html

There is some good stuff out there for controlling, since both are rs232 (serial) devices.

rooarko

JB_AU I like where these are going as I live in the UAE and it does free shipping to the UAE, but could you give me some more info on what both are as I am a NEWCOMER and I don't understand a lot of what you're talking about. But trust me the stuff I do understand, is really getting me excited!
Thanks please rep.

JB_AU

Apologies for the late reply.

The boards are controllers for up to 32 servo motors, there is also a 16 servo shield now;
http://www.renbotics.com/servoshield2.php

That will drive the motors for your robots

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