Power Wheels motors and the HB-25 motor driver.
photomankc
Posts: 943
I scavenged the motors from daughter's old Barbie Power-Wheels car. Spent the weekend searching for some specs on them and from what I have found they are monsters.
Free Running they pull around 2A and can reach 70A in full stall! (Mother of baby Jesus). RS550 type body. ~16700 rpm with no load. So, I have been looking around at what I can do to use these and have discovered that planetary gearboxes are expensive. Motor controllers that stand a chance of being able to supply these things are also expensive. I'd expect that at 80 to 100:1 reduction that they would be frighteningly powerful given that I have not been able to stall them at the 1/2" pinion gear with anything at my disposal thus far without running the risk of the material bursting into flames. All looking like cool stuff for a an outdoor heavy-duty robot.
The thing I am concerned for is the surge current. The resistance through the coil is about 0.3 Ohms as my meter reads it but I'm guessing it's less than that really based on the specs. So would an HB-25 have any hope of running one of these beasts? I think the the continuous current is probably reasonable but I worry about the surge current and possible serious overload if they were to full-stall. The other thing I am looking at is a SaberCat 2X60A control that would be capable of handling all but the absolute stall current. They also make a 2X25A that claims to be able to handle 50A peaks so that's a little closer.
Since dead power wheels are everywhere owing to little more than bad batteries/chargers or kids that lost interest I figure getting more of these will be easy to do but the cost of the supporting cast to manage them may be more than it's worth to use them.
Planned use is an outdoor 4x4 rover with the ability to oh, say plow snow or tow a mower.
Free Running they pull around 2A and can reach 70A in full stall! (Mother of baby Jesus). RS550 type body. ~16700 rpm with no load. So, I have been looking around at what I can do to use these and have discovered that planetary gearboxes are expensive. Motor controllers that stand a chance of being able to supply these things are also expensive. I'd expect that at 80 to 100:1 reduction that they would be frighteningly powerful given that I have not been able to stall them at the 1/2" pinion gear with anything at my disposal thus far without running the risk of the material bursting into flames. All looking like cool stuff for a an outdoor heavy-duty robot.
The thing I am concerned for is the surge current. The resistance through the coil is about 0.3 Ohms as my meter reads it but I'm guessing it's less than that really based on the specs. So would an HB-25 have any hope of running one of these beasts? I think the the continuous current is probably reasonable but I worry about the surge current and possible serious overload if they were to full-stall. The other thing I am looking at is a SaberCat 2X60A control that would be capable of handling all but the absolute stall current. They also make a 2X25A that claims to be able to handle 50A peaks so that's a little closer.
Since dead power wheels are everywhere owing to little more than bad batteries/chargers or kids that lost interest I figure getting more of these will be easy to do but the cost of the supporting cast to manage them may be more than it's worth to use them.
Planned use is an outdoor 4x4 rover with the ability to oh, say plow snow or tow a mower.
Comments
What you might want to look into is the power wheels racing circuit
http://boingboing.net/2012/08/29/modded-power-wheels-racing.html
It takes a little searching, but some of these guys have done some stuff in this area, it looks like a blast! I have a barbie car that may be destined for HOG wheels.
The HOG wheels get you continuously variable transmission, and omnidirectioal stearing. Nuts, yes; improbable, yes; on the list, yes.
I've done tests on several auto salvage yard type of motors.
It would pay for you to do a simple test on your "daughter's old Barbie Power-Wheels car"
to see what it does.
Chances are that you will find, they will never pull 70 amps.
HB25 controllers are very good and very controllable.
The fuse that is incorporated into the controller will protect the controller.
While you may need something to limit over current other than the HB25 fuse, It would be worth your while
to bolt the Barbie motors to your workbench, if you have one (lots of people don't have a generic workplace)
The useful current drawn by the Barbie motors will more than likely be very usable.
I do repurposing of old stuff, and I've found that sometimes just protecting your new controller gear is more than enough
to get you started on a very good new adventure.
Thats my two cents worth.
Good luck on your projects.