Let's Make Robots!

"Scrappy" the 10euro robotic arm

makes noise
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35-RealArm_target_circle.bs2_.txt6.76 KB
robotic_arm2.xls49 KB
2D_kinematics.pdf4.99 KB
3D_kinematics.pdf4.06 KB

As a total moron, I've deleted the previous robot page while trying to clean some attachments

 

So, let's start again..

Steve the disembodied robotic arm as been a source of inspiration for me

I've found tons of nealy free micro servos on ebay..  so I decided to give a try

 

For more than a week now, I've been working on my excel simulator, and BS2 implementation of my inverse kinematics algorithm,

 

which is now able to reach a X,Y,Z target using 4 servos

 

I've just recieved the servos today ;)

 

So I took some foam board and tie wraps... to make something tangible 

 

It's alive ! 

despites the fact that "on paper" the really low torque of those servos could lead it to be a total failure 

 

 

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serial connection

 

for the moment my excel app. is using a m$ specific component,

 

But I've just tested what I've discussed in my boebot page : we can still access a serial port as a FILE !

 

windows scripting example   (could be pasted "as is" in an excel macro) 

set oFSO  = CreateObject("Scripting.FileSystemObject")

set  f = oFSO.OpenTextFile("COM1:9600,N,8,1", 1) 'for Reading

'  f = oFSO.OpenTextFile("COM1:9600,N,8,1", 2) 'for Writing

'  f.write("abc")

dim buffer

buffer=""

do until len(buffer)>250

 Do While f.atendofstream <> true 

buffer=buffer & f.readall

   Loop

loop

msgbox buffer

  f.close

 

I will continue tests on this license-troubles-free serial port connection in Excel 

How are you interfacing with the PC/Excel? Are you using serial or usb? Just curious...

I've got some of these small servos and because of their low torque may I suggest that you make it out of balsa wood to begin with and use some rubber bands or springs to counter some of the weight. If you have enough servos then two working together at the base like "Steve" has would be a big advantage.

I'm interested in the inverse kinetics but I won't have a chance to play with it yet. When you next update this page can you put it in the tags so that I can find it later.

sorry guys, I messed up and have deleted the complete robot page while trying to delete the attachments

 

here is a link I'd like to share with you :

http://freespace.virgin.net/hugo.elias/models/m_ik.htm

http://freespace.virgin.net/hugo.elias/models/m_ik2.htm

 

I really like the configuration space approach,  but it's probably much to heavy to run on a microcontroller