Science Buddies: "Ask an Expert"

D o you think the difference in magnet compounds in electric motors is a good project?

Hi:

Could you be a little more specific as to what you are thinking about studying in your project? What exactly would you study, and how would you test your hypothesis?

Often the best approach is in the terms of a question like, "What is the effect of x on y?"

Are you intending on building the motors, or comparing similar motors with different magnets (probably hard to find such similar motors)?

Accually, I have a couple 130 size motors I don't really need. I can use the stock magnets that came with them (I'm not sure what they are made of) adn I can order neodymium magnets off of the internet. I want to test and see which magnets will have more performance on the motors.

OK. I also found some sites with neodymium magnets. You will need to match the size with the present magnets, so that the only variable you are changing is the strength of the magnetic field associated with the different magnet materials.

You will need to come up with a plan for measuring the performance of the motors. Have you thought of how you will do that? There are many ways to do this. You will need one that can show a difference between the magnets you choose (which might only be a slight difference.)

You may also want/need to measure the magnetic strength of the magnets you use (or purchase ones of known magnetic strength).

The project is a good one if it interests you. If it gets you to dive into the research and enjoy the process of performing the experiment, it's a good project.

Thanks, and I'm going to see which motor powers which car better, which I will grade in 3 catagories:

1. Highest incline able to climb
2. Top speed
3. Run time

Thanks, and I'm going to see which motor powers which car better, which I will grade in 3 catagories:

1. Highest incline able to climb
2. Top speed
3. Run time

The first two sound fine. I'm not sure how run time would relate to the motor magnets (more like a test of a battery source.)

I stumbled upon your post, and as someone who has worked with neodymium magnet (a semi-successful Maglev project last year), I thought I should warn you to be VERY careful when working with multiple magnets. If two of these magnets get to close to each other they will attract and collide and very high speeds, which can--and will--shatter the magnets. Most rare-earth magnet websites recommend using goggles whenever handling them, as shards of the magnets will fly off at high velocity when this happens. And believe me, no matter how careful you are it will happen at least once!

Also, if you're playing around with them like my roommate was, you could seriously hurt yourself like he did. The magnets crushed the cartilage in his ear and it is now permanently mishappen. So do not play with them!

http://www.atomicmods.com/ProductInfo.a ... ctid=12305

this is where I want to get my mags from.

Looks reasonable.

I agree with DKirby's post about taking care with the rare-earth magnets. I have a pair that I use to clean my fish tank glass (0.75" glass). Each magnet weighs about a pound. One time I accidentally got them stuck together. It took a huge crowbar and vise to remove them, and fortunately, I didn't lose any fingers. Fortunately, your magnets are much smaller.

I'm assuming that you will be using a 130 sized motor. I'm also assuming that this is a standard sized motor for an RC car. Let me know if this isn't correct. I only saw the one set of Neodymium magnets. Using the original set makes two types of magnets. You should at least include one other set of magnets of a different strength. (You will want your variable to have at least 3 separate values.)

Do you have any idea where you can find them?

Start thinking about what will be your controls, and variables.