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Topic: GIANT Servo setup (Read 2217 times) previous topic - next topic

msamford

This should not be a topic that has been covered before, or at least not in this way.

I have a 24 volt dc motor geared down to 16rpm.
I have a small rc servo that I have taken apart.

My plan is to put a gear on the motor, replace the potentiometer in the servo, add a gear to the top of it, and connect it to the gear on the dc motor.

In my understanding, this will give me a giant 24volt servo.

If all the above is correct then here is my issue:

I will need a motor controller to operate the motor.
I will run the 3 wires from the servo motor to the arduino pins of +5v, grnd, and digital pin 7.
The other end if the positive and ground wires will run to a motor controller.

The motor controller will be connected to a seperate power supply that drives the dc motor.

will this setup work the way I am expecting it to or am I missing some key component?

All feedback is greatly appreciated. Flame away if you will.
If this topic has been posted before, I apologize. I spent about a week researching to come up with this design.

The reason the servo needs to be so large is it will be rotating about 100 pounds of steel with large resistances.


zoomkat

Quote
If this topic has been posted before, I apologize. I spent about a week researching to come up with this design.


The idea of using the guts of a servo (servo pot at the point of movement and servo motor leads driving the large motor h-bridge) comes around fairly often. The usual slowing down issue is the cost of the large h-bridge to operate the big motor (which should not be a factor in weather the setup will work or not). I've got this particular plan for a giant servo (below) on the back burner while looking for the h-bridge solution.

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msamford

Quote
The usual slowing down issue is the cost of the large h-bridge to operate the big motor


This is the part that is completely foreign to me. I am trying to figure out exactly what I need to do for this, but im still unsure.

I was hoping that by using the motor controller that this wouldnt be an issue.

zoomkat

Quote
I was hoping that by using the motor controller that this wouldnt be an issue.


An appropriate motor controller (which usually contain an h-bridge) for the motor could work. What is the size of the motor and the motor controller you want to use?
Google forum search: Use Google Search box in upper right side of this page.
Why I like my 2005 Rio Yellow Honda S2000  https://www.youtube.com/watch?v=pWjMvrkUqX0

msamford

The size of the motor is 24vdc.
I am not sure what the amp usage is.

I am actually thinking of purchasing a new motor so that It can be 12v and known amps below 10.

I understand that the arduino motor controller only goes up to 2 amps so I have downloaded a tutorial for building an h bridge that I will use with it.

I am not sure that the one I downloaded will work though because it has 3 inputs from the microcontroller with seperate spots for forwar and revers which wont work for me.

I am still working on finding a hbridge design to build.

zoomkat

#5
Jul 15, 2012, 09:23 pm Last Edit: Jul 15, 2012, 09:38 pm by zoomkat Reason: 1
Quote
so I have downloaded a tutorial for building an h bridge that I will use with it.


Be aware that many "intrenet H-bridges" just don't work in the real world. Below are previous post on DIY h-bridges that might be worth reading.

http://arduino.cc/forum/index.php?topic=53425.0

https://www.google.com/search?hl=en&as_q=h-bridge+build&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=http%3A%2F%2Farduino.cc%2Fforum%2F&as_occt=any&safe=off&tbs=&as_filetype=&as_rights=
Google forum search: Use Google Search box in upper right side of this page.
Why I like my 2005 Rio Yellow Honda S2000  https://www.youtube.com/watch?v=pWjMvrkUqX0

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