Small electric motor to power something along a track?

I want to build a circular track and power a pretty light cart along the track... doesn't have to be fast... only 2-3 mph. I need a way to power it.

I thought first of making a center pole with an extension cord coming out, but as the cart continues in circle, the cord would twist and twist then knot.

I then thought I could power the wheels with a car batter(ies). However, I don't know the first thing about how long a charged battery would be able to power a light motor, etc. I don't know the first things about electricity, so any help or reference material would be appreciated.

Is there a better way to do this? A rotating plug on the pole, for example? Simple diagrams to show how?

Thank you so much!

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maxlds (author) 6 years ago
Okay, all! Thanks for your help. Along the same lines... let me give you more definition:

Box made out of plywood (or foam?) 3'x2'x3'
Track made out of plywood as well? Slot car design.
Metal wheels and axles (propel with back wheels?)

1. I could create a giant circle track out of plywood and router a slot down the middle. How would I lay the metal/what metal do I need to use? This should be able to be taken apart

2. What size motor to power something like that? I'd add 20 lbs of stuff inside, too

3.Transform 120v house wiring to what?

Thanks, guys! This makes a big difference! :D
You'll also need to route out grooves into which you'll place the rails. For a slot car type approach, the best approach is the make the rails stand just slightly proud of the FINISHED "roadway" surface, one on each side of the center slot (if you plan to paint the roadway or apply surfacing materials, I'd installed the rails as a lest step, and not just because they might get paint on them, the paint and any other material will build the surface up...!)

I'd transform down to a maximum of 24V. And although 24VAC *might be practical, I'd also be inclined to make that 24VDC just to be safe. The final voltage will be dictated by your choice of motors.

Whoa. Twenty pounds? Erm...what are you planning again?

That is, how big are you planning on making the vehicle?
maxlds (author)  seandogue6 years ago
Yeah, so motor size is going to be a problem... hence I need the suggestions as I've not done this before. So, I could make the rails using aluminum wire, correct?

So, let's say I want a 20 foot diameter circle
3 foot by 2 foot by 3 foot plywood box
Then I'm just guessing a random 20 lbs in the box.

Motor size? Torque?
Would one power source work to power an aluminum rail with a 20 foot diameter?
You said transforming down to 24VAC, but 24VDC to be safe.

It's just a prop, but I'm quite concerned about someone touching both lines at once. I don't want a lawsuit on my hands What's safe?

All of your guys' thoughts are VERY helpful... Thank you!
~63 feet is fine, as long as the conductor is heavy enough to supply the current required for your application. The thinner the conductor and heavier the current draw, the larger the losses in the conductor and so reduction in the voltage that reaches your motor. I'd consider something along the lines of 10-12 gauge wire, like you'd find in household wiring.

24VDC. DO NOT use 120VAC to directly power the rails under any circumstances.

the "truck" itself, well, I can't really advise you on the specifics. That you're going to have to figure out. See if there's an electronics surplus store nearby, where you can purchase relatively inexpensive motors, so you can do a bit of trial and error.
maxlds (author)  seandogue6 years ago
Perfect.... 10-12 gauge. And would aluminum work best then?

I knew 120 VAC would be a VERY bad idea. Is the 24VDC completely safe then? As in, if a kiddo touches it, will it not hurt them? Like at all?!

What about mA on the rails? I know nothing about this stuff, but I wanna be safe.

I think I can figure out the "truck". So long as I have a rough idea on this other stuff.

Does the attached drawing look like it makes sense?

You may want to drop it to 12VDC if you're really concerned, it will be wet, etc. Technically, 24VDC is "safe". However, since I cannot guarantee your setup (since I'm not actually building it), I'll suggest 12V, although that could be problematic for driving your motor. (12V is commonly used for indoor HO raceways and rail)

One problem though. Losses in the wiring will be more evident, especially when the large currents required for pulling a heavy load are in play.

For a +20lbs load? You're looking at an amp or more, at a guess. All depends, and honestly, you're going to need to do a bit of experimentation on your own for the specifics.

Your drawings look to be in order.
maxlds (author)  seandogue6 years ago
seandogue - Looks like it's time to order some materials and try this out! Thanks for all your help! I feel confident about this now. I think I'll go 24vdc
Burf6 years ago
Check out model railroading, this problem was conquered decades ago. Electrify the track, low voltage to each rail, AC or DC from 6 to 24 volts.
kelseymh Burf6 years ago
That's how slot cars work as well.
Burf and kelsey good answers. +1 and +1.
maxlds (author)  Burf6 years ago
How this didn't cross my mind, I just don't know. Makes a lot of sense... now I'm looking more into it to see if it will work in my situation! So, thanks!

Keep the ideas coming people!
seandogue6 years ago
Now, what would be cool is if you could power it inductively. Once upon a time, I started sketching out a maglev toy much like a model road racing or rail set that would have employed such a method, but the tech wasn't nearly there and the naysayers were in such abundance that I pitched the idea into the trash bin. So long 1980, Hello cave.
maxlds (author)  seandogue6 years ago
No joke! That crossed my mind... Ah we're closer!
lemonie6 years ago

How about using magnets and building it above a (olde-fashioned "record") turntable?

maxlds (author)  lemonie6 years ago
Awesome! However, I'm building it pretty build and outside.... hmm...
That is a cool idea. brillig!