Science Buddies: "Ask an Expert"

I am working with 4th Grader daughter on Flippy the Dancing Robot project and we are currently facing a problem.

I have two 3V DC motors connected in parallel to 4.5V (3) AA batteries. The Motors work..but when its put on the floor , its unable to lift the weight. Can you please help,

On sparkfun : https://www.sparkfun.com/products/12866

This link brings up a chassis ..which I am not interested in.

Amazon has:
http://www.amazon.com/130-16140-12500RP ... AZDOWP300U

Would this work with 4 AA Batteries?

Thanks,

Hi diyas,

We recommend purchasing the chassis for that project because it comes with geared motors. The motors are geared so they spin more slowly but are much stronger (they have a higher torque), so they are capable of pushing the robot around. The type of motor you linked on Amazon is not geared - so it will spin very very fast, but will not be strong enough to lift the robot's weight.

You can buy those exact geared motors directly from the manufacturer of the chassis (Dagu), but for whatever reason a single pair of motors is almost as expensive as buying the whole chassis from SparkFun (and I think you also have to wait for shipping from China):

http://www.dagurobot.com/category.php?id=108

It looks like the same motors are also available on Amazon, but again at $7.63 each, it's cheaper to just buy the chassis from SparkFun:

http://www.amazon.com/Robot-Smart-15RPM ... B00BG9K8UG

The other advantage of the chassis is that it can be used for four of our other projects, if your daughter is ever interested in more robotics projects in the future. The chassis does not come assembled, so you can still just use the motors to start with:

https://www.sciencebuddies.org/science- ... p022.shtml

https://www.sciencebuddies.org/science- ... p023.shtml

https://www.sciencebuddies.org/science- ... p024.shtml

https://www.sciencebuddies.org/science- ... p028.shtml

I hope this helps, please let me know if you have other questions.

-Ben

Thanks a lot Ben..

Didnt think the motors being geared... I went ahead and ordered

https://www.sparkfun.com/products/12866

I will close the loop with you when we get it working.

thanks again,

Thanks - I will update the materials list of the project to emphasize that it requires geared motors.

Since you already have the regular 3V DC motors laying around, there are a couple other projects you can do with those (you will only want a 2xAA battery pack though):

https://www.sciencebuddies.org/hands-on ... s/brushbot

https://www.sciencebuddies.org/science- ... p014.shtml

Let me know how it goes, we always appreciate feedback on our projects. Happy New Year!

-Ben

Hi Ben,

Using the geared motors worked like a charm!.. The other projects you recommended with this kit are very interesting as well.
I will surely encourage my daughter to try them.

thanks a lot for all your help. Much appreciated!!

No problem, please let us know if you have any other questions or feedback. Glad it worked out!