Feasibility: Moving targets DC Motor control w remote

I am planning on making a small wire pull system for moving air rifle target in my garage. Looking to control speed, direction, delay between cycles, and length of pull, preferably with remote. The entire project will be fitted within a plastic casing, with only a pulley wheel and on/off switch protruding from it.

I want it to start, travel a certain distance in controlled speed, stop, delay x seconds, return to start, and repeat.

Since this is my first project, I think I am going to make 2 iterations:

  1. Simple on/off control, and programming done in the coding only. The pull system will only follow the preset program. (1)

  2. Control using remote for on/off, and speed "settings". Perhaps most practical to code preset programs than being able to control details with remote. (2)

The plan is to simply strip an USB cable and use 5V USB to a phone charger adapter, alternative is 9V converter and a 9V power input?

From my extremely limited experience, this is what I am planning on buying:

  • Arduino Uno board (1)
  • L298N Motor Driver (1)
  • 5V stepper motor (19
  • 2272-M4 Non-lock 4-Way Remote Control Module w/Receiving Panel (2)
  • Cables (1)
  • 5V USB cable "stolen" from the house somewhere (1)
  • Plastic case to install in after testing (1)

From my initial list and plan, any thought or improvements?

Any tips for gear and shaft kits? I had a kit from one brand before, that I can't find the name of, but very practical with standardized kit where all shafts and gears fit that you can easily supplement.

My plan was simply using a curtain rail and looped wire, as it will be hanging under a shelf, but suggestions for nicer versions or rails are very welcome!

The L298N is really old technology. There's a lot better stuff out there.

If you plan on driving a stepper, then that's completely the wrong driver. For the common steppers you are likely to use, a dedicated stepper driver is essential. Select one from here.

Your power supply is inadequate too. The maximum a USB device can draw from a computer or charger without negotiation is 0.5A. You need at least 1A to drive a stepper adequately. You also need more volts. Volts=speed for DC motors, even stepper motors. A 12V 1A or 2A supply would be much better for this. You can even run from a 12V battery for a couple of hours, depending on the size of the battery.

Re-purposing a curtain/blind rail sounds like a good idea. Use the same kind of cord as what came with the curtain.

MorganS: The L298N is really old technology. There's a lot better stuff out there.

If you plan on driving a stepper, then that's completely the wrong driver. For the common steppers you are likely to use, a dedicated stepper driver is essential. Select one from here.

Your power supply is inadequate too. The maximum a USB device can draw from a computer or charger without negotiation is 0.5A. You need at least 1A to drive a stepper adequately. You also need more volts. Volts=speed for DC motors, even stepper motors. A 12V 1A or 2A supply would be much better for this. You can even run from a 12V battery for a couple of hours, depending on the size of the battery.

Re-purposing a curtain/blind rail sounds like a good idea. Use the same kind of cord as what came with the curtain.

At least one part of my idea was good :)

You think it is adequate to use a 9V input to the Uno board, and run it from there? Will simplify the design a lot, as I can run both USB and 9V through the casing.

I have a few 1,5/2A USB chargers, like the one for IPads, but it's best with higher voltage in?

Pardon my ignorance, but what is wrong with the L298N? It's my first project, and this is the one I find the most referenced, but maybe that's because of the availability.

The L298N is unable to send all of the input voltage to the motor. It has a fixed voltage drop due to the transistors used. On low voltage (like 5V and under) this is a huge percentage of the power available. At high power, like over 1A, the L298N gets hot. A modern chip can do 30A without getting as hot.

It's also the wrong thing for steppers. A stepper works best with a current-controlled source, instead of a voltage source.

Thanks for the quick reply!

Ok, so is this more suitable? http://www.dx.com/no/p/28ybt-48-stepper-motor-with-uln2003-driver-dc-5v-126409#.Wi3QL4yUmEc

Is it better to use an uno than say a Micro Pro? Seems i can then maki it much more compact. Planning on wiring directly.

That little stepper is going to struggle to pull a target along a long track, even if the target is just a piece of paper.

Grab a piece of the cord/string as long as you need and try to drag it along the floor, around a chair leg and back. Get some idea of how much force you need. Then convert that to torque using your desired pulley size. Then multiply by speed to get the power required.

The track is only 7-8 feet long, but I see where you're getting at. I'll probably try using the starter kit to do a mock-up, then order a 9 or 12 volt stepper motor.

Can I run the power throught the Arduino board, or will this reduce the voltage to 5V? I thought the VIN pin sent approximately the same V out as the input to the board?

Both the Arduino and the motor(driver) should have their own wires going to the power source. Don't forget to do the same for the ground as well as power.