Looking for value(cheap) 12v battery/motors for my project

Community General Discussions
1

This question is a few parts, too related to each other to make seperate questions.

I currently am using the same type of 6v motors that came with the starter kit. My current robot is partially a pickle bucket weighing about 10 lbs under full load with stuff mounted. I cannot get good enough power to the wheels to go over a lip up to carpet. 

I ordered a 12v to 5v stepper. My current motors get 1A shared at 5v. Would giving it more amps from the converter make a bigger difference, or would putting a 12v line through a cheap 6v regulator do better? I'm on a budget, but if I would need higher voltage motors, could you recommend cheap motors/wheels?

Again, the robot currently weighs let's say 10lbs, and I don't have a 12v battery yet. On that note, what decent but cheap battery would you recommend I get? I calculate he 12v battery amp draw from the battery would be 1.6A  for the logic, then either:
-1.6A(max) for the 2 servos and current motors if giving them a total of 3A@5v; or
-However many amps the 12V motors take, then I connect the servos to the logic and raise it an amp.

So, with the current motors, I'm looking at 3.2Ah draw. I need something that can last it a few hours. I have a 5V battery pack I can use to extend the life if the need really be.

I'm also posting for help on the control arm in the 3D printing forum here, if you find it related.
Also, sorry if this seems sloppy. My thoughts are all over the place, and I rewrote this probably 4x. XD 

2

Thanks, I’ll look at the

Thanks, I’ll look at the motors in a minute, but on the battery, those are all rated only 5Ah, when that might be done in under 2h, depending on how much the robot is doing.

The stepper for the batter is this: 
http://www.ebay.com/itm/261322520291

3

Your cheapest alternative
Your cheapest alternative for a battery is a 12v SLA (sealed lead acid). I would also prefer LiPos, but a 10 amp-hr 3S cell would cost a lot more and weigh less than the SLA.

As for motors I’d look at 12 volt motor on eBay and see what they have.

4

**cheap 12V motors **
You can get 12V motors designed for automobile electric window openers. The ones I have come with heady duty right angle gear boxes. The gea rheads are different for the left & right doors.

George

5

I’m just pointing this out,
I’m just pointing this out, because your use of the word “stepper” confused the hell out of me. The item in question is called a “voltage comverter” and a few other names having to do with voltage, such as a “switching voltage regulator.”

6

Or step down voltage

Or step down voltage regulator. Stepper is usually the short for stepper motors.

7

Or just one 12v motor

 A 60RPM 12v geared motor should be enough to pull 21lbs at 1m/s^2 with a wheel of 4cm. Add servo steering on the front wheels and should be good to go. Or 4 6v motors.

About batteries NiMh AA are a great way to discover how much current or voltage is needed. Get 5 in series to make 6v, 10 to make 12v, in parallel to get more charge; then get a Lipo that suits the needs.

Battery adds weight too, and lipo are more energy/weight efficient.

8

Thanks

This was the first response I saw today, and after what Duane said, I was thinking Lipi too.
For the motors, thanks for the numbers, glad to know someone was able to understand my chatter and give me numbers! XD 

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That was my intention

I’d care about max RPM, torque and wheel size.

10

How about these?

Again, considering my robot may be… ~10lbs, do these look like they may be suitable?
http://www.sourcingmap.com/45rpm-6v-n20-dc-geared-motor-rubber-wheel-for-diy-robot-smart-car-p-314484.html

11

I don’t see much in the way
I don’t see much in the way of real stats in the link you gave us. It’s made for a small robot and goes 45 RPM, and I suspect the gearbox will tear itself apart if pushed too far. It’s got a 3mm shaft, which isn’t much.

However I don’t know enough to be sure. Also, these are six volt motors and you’re asking for 12 volt motors?

12

I said I’m willing to accept

I said I’m willing to accept 12v motors if those will do the job better, though I prefer ones that will work on 5v. :slight_smile:

There’s a whole thread about friction here now, but hardly any recommendations on what I could get for cheap, with wheels I could use on the said axles. :/ 

13

Look at the used market, and
Look at the used market, and get two matched motors. I like the idea of using automobile window motors. Now, they aren’t the most efficient motor possible, but they are usually inexpensive. They’re available at most auto wreckers and many surplus outfits.

I’ve heard of truck windshield wiper motors also being used.

An SLA (sealed lead acid) battery is the cheapest battery you can usually find, but it’s also near the heaviest.

Some times I feel deciding on a motor and battery combination is like running the Red Queen’s Race, where you have to run as fast as you can just to stay where you are.

You may have to make a huge that connects the motors to the wheels. This can be complex as a machined aluminum hub, or as easy as a short length of garden hose tightened down on both ends with a hose clamp. Or even a PVC pipe. It all depends on the motor and the wheels you can find.

I like the motors from Paralax that Duane suggested. I ordered myself a set but they haven’t arrived yet.