Servo Controller with wired armature/telemetry arm

Support Servo controllers and servos
1

Hello

I own a hobby shop and I am helping our local high school participate in a robot arm competition. I want to use standard RC servos and I was going to take apart a standard hobby radio and use the potentiometers to build a armature or telemetry arm like device for the kids to control it. But I have some questions now that I ran across your products.

  1. Will these servo controllers do a more precise job that a standard RC radio?
  2. What are my options when it comes to mechanical control? I do not want to use a computer, I do not need to have any scripts or automation at all. I would like to find a way to just use potentiometers with a homemade control/armature.
  3. Any thoughts or ideas on this project?
  4. Any good sources for parts I can use to make the arm allowing for rc servos as joints?

The arm will probably have 5 servos total, only a couple foot long and has to move some pennies around on a paper target. I want the kids to bring something to the event that was not just bought off the shelf, I want them to build this thing and make something unique.

Thank you in advance.
Mark

2

Hello, Mark.

I moved your post to the servo controller subforum. I have numbered my responses to your questions below:

  1. In general, the Maestros can more precisely produce a standard hobby RC servo pulse than other devices, like RC transmitters or servo testers. However, if you are adding a potentiometer as an input, and the potentiometer is not very precise, then regardless of the precision of the Maestro’s servo signals, the overall precision of your arm system will be determined by the potentiometer.
  2. You will have to write a script for the Maestro to read the potentiometer inputs and generate whatever servo signals you want based on those inputs. We have a “Using an analog input to control servos” example script, which you can use to get started programming. You can find that example inside the Maestro’s user’s guide, which can be found under the “Resources” tab of its product page. Once your completed script has been uploaded to the Maestro, you can disconnect it from your computer and power it separately. So, you do not need a computer connected to the Maestro in order to run your robotic arm.
  3. Not particularly. However, please feel free to share your project when you are ready! We are always excited to hear and see how people use our products.
  4. We do not have any specific recommendations, though if you are looking for metal components, you might try ServoCity.

Since you are planning on making a robotic arm that uses five servos, I recommend using the Mini Maestro 12-channel, which has enough channels to dedicate to each servo and a potentiometer to control rotation around that servo. (Each input and output in a system controlled with a Maestro needs a dedicated channel.)

-Jon

3

Thank you so much Jonathan.

So we do not have the people to do any script programing at this time. Do you think there are people on the forum who could do this for us and we can download the scripts?

Also, where and what type of potentiometers could I use for your boards? I would be interested mostly in the type of costs for a decent one, we talking $10 each or more?

Thank you again for your help. I will do some more exploring on these and other options.

4

You can try advertising for a programmer on our forum, but I suspect it won’t be as fruitful as using other websites or forums that are focused on connecting programmers to people with a project in mind. (We don’t have any particular recommendations for one of those websites.) Scripting with the Maestro might seem daunting if you are new to programming, but you can basically use the example I referenced above in the Maestro’s user’s guide with little or no modification in order to get a potentiometer to control a servo. So, you might just try it out, and if you run into any trouble, you could post what code you have tried, what behavior you are getting, and we can troubleshoot.

Something like a 10k potentiometer should work fine. We do not carry any, but you can try searching sites like SparkFun, Adafruit, or DigiKey.

-Jon