What do I consider in chosing 5v DC vs 12v DC

Other Hardware General Electronics
1

I have 2 sets of DC motors and they are going to drive 2 antenna mounts. One is for rotation and one is for whatever it's called for the up and down motion.
For the 12v I will have to hook up 2, 7v batteries to get the desired 12v or go shopping for the 12v battery.
For the 5v I have the batteries.

So, what do I consider in choosing between the 2 ? Is it the weight of the antenna mounts plus something having to do with how easy they rotate and pitch ?

thanks

2

Azimuth and elevation are the terms you are looking for. You need to bear in mind windage and the load on the bearings.

3

Power is :
I^2 * R
V^2 / R
V * R
The practical upshot of this is that if you double the voltage (very roughly from 5V to 12V) you halve the current for the same power output.
So, a higher voltage means a lower current for the same power output. You should take the power output of the motors into account and the current they need to produce that output. The higher voltage motors will draw less current to do the same job, require correspondingly thinner wires and lower current drivers. They will also be less sensitive to losses caused by high resistance connections, for example loose connections, bad soldering etc.

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4

Please post full details of your motors. Can you explain the mechanical arrangement and and forces/torques
for this antenna?

The order to tackle this is first to sort out the mechanical details - what loads / torques / speeds are needed.

Only then can you know the power and gearing requirements for a motor. Yes you'll need gearing for something
like this, and you have the option to choose gears like worm gears that cannot be back-driven, which can be
useful.

And after you've some candidate motors can you know what voltages/current options are in order to
select a motor driver.

5

Well folks, I will have to get back to you with answers to your questions.
I am in the process of making a satellite tracking system, using an arduino and 2 servos connected to the mast and antenna. The system sorta works but I compared it to a high-school project that I saw that I think was better. It was a lot smoother and it used the dc motors to control the movement rather than servos.

The original servo project is here:
Servo tracker

and the DC motor tracker is here:
DC Tracker

Had I of seen the DC tracker 1st, I would have started there, but here I am.