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Author Topic: Rhino SCARA Robot  (Read 1971 times)
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Memphis, TN
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Hi Everyone,

I'm new here, but I'm using an arduino for this project, so I figured this would be the best place to seek help/guidance. I'm working a project and have run into a couple of questions before I proceed. A little background info first..The project uses a Rhino SCARA (See first link below) and an Arduino uno. My objective is to eventually get the robot interfaced with the arduino so that it can be programmed to do simple tasks (such as picking up an object, placing somewhere and moving back to the home position) for the purpose of getting this robot worked back into the cirriculum at the university. The robot's wiring has been completely obliterated by whoever was the last to mess with it, so if you checked out the link to view the SCARA robot I'm working with, picture that, but with no wiring.. The robot was bought by the university back in the 70's (which is why finding info on it is difficult). Since the robot is so old and has apparently been through a lot, my first step of the project is to test all of the components on the bot. I've tested all 5 motors to assure that they are still functioning, which they do.  My next step is to figure out a method for testing the encoders attached to each motor's shafts. The second link below has somewhat detailed info on the encoders. The company (Rhino Robotics) is awful about communicating back and the manuals aren't worth a crap..They responded to one of my emails a couple months back and have not done so since, so I know the company still exists.   smiley-confuse ..... Anywho, could any of you suggest a method for testing these encoders?

1). http://www.rhinorobotics.com/scara.html

2). http://www.rhinorobotics.com/xrencoder.html
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Dubuque, Iowa, USA
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According to the doc the "optics" encoders appear to be quadrature encoders. This tutorial shows an encoder knob that is functionally and electrically equivalent to what you have.
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The picture of that robot is pretty poor, but from the look of things, those motors appear to be Pittman DC motors, with encoders. Have you tried contacting the current manufacturer of these motors (whomever they are) for datasheet info (and hookup info for the encoders)? If they are Pittman, contact info here:

http://www.ametek.com/locations/pittman-location.aspx

Note - be nice, state what you are wanting in plain language, offer to pay for the information (literature shouldn't be too expensive - but I can tell you that the gears in those motors are not cheap, so don't break them!).
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Thanks for the help guys!

According to the doc the "optics" encoders appear to be quadrature encoders. This tutorial shows an encoder knob that is functionally and electrically equivalent to what you have.
I read this and tried to run the code for the encoder without a pushbutton, but did not receive results. Two problems on my end that are causing no feed back with the program provided on the page you referred me to are 1). I don't know how much voltage these encoders are supposed to be supplied with (I've tried 3.3V and 5V). Having said this, when I connect power to the encoder, it's not drawing any current. 2). As cr0sh and I are discussing, I have not found a way to get a datasheet on the motors/encoders to figure out the information needed as stated in my first point.

The picture of that robot is pretty poor, but from the look of things, those motors appear to be Pittman DC motors, with encoders. Have you tried contacting the current manufacturer of these motors (whomever they are) for datasheet info (and hookup info for the encoders)? If they are Pittman, contact info here:

http://www.ametek.com/locations/pittman-location.aspx

Note - be nice, state what you are wanting in plain language, offer to pay for the information (literature shouldn't be too expensive - but I can tell you that the gears in those motors are not cheap, so don't break them!).

Yes, their whole website is poorly put together. Anywho, you are correct about the motors being pittman. I tried to email them on January 9th, but they did not respond to my email. I also offered some type of compensation for the information, but still nothing. As I mentioned above, when I apply power, the encoder is not drawing any current. I've tried connected to three of the five just to see if one or two may be bad or something, but I don't think that's the problem. I've got the red wire connected to power, the black to ground and the blue and green wires are Channels A and B (if encoder in the link that Chagrin posted is similar to the ones on these motors) of the encoder which are connected to pins 2 and 3 on the arduino.  I think I'll try and call Pittman to see if I can speak with someone directly because datasheets would be extremely helpful.
« Last Edit: January 14, 2013, 12:48:08 pm by Jeffro » Logged

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