Building an AC Motor AND a DC Motor + other questions (1 Viewer)

[henry08]

Hi guys. I've read these forums for abotu a year and a half now and have learnt soem great stuff from BOS. Anyway, I need soem serious help with this, so I thought who better to ask?

First off, I have read through the 11 pages of topics in this subforum although didn't really find the answers I am looking for.

I have to build a DC motor, build a sperate AC motor and complete an analysis and report on thse. I've read about Beakman's motors, and paperclip/mathbox motors althoguh thse are too simple and we are not allows to do these. My motors will be similar to teh DC motor in teh Jacandra Physics textbook (which I never did get to work lol).

Some questiosn I have:
1. Where do I buy bar magnets? Bought some magents (rare Earth ones I think no lol) today. Were so powerful I can't pull them apart.

2. Are corks suitable to use as the commutato/armature base?

3. With the AC motor how do I supply power to it? I.e batteries are DC and I don't want to just stick the conecting wires into a power plug socket lol (i'm joking).

4. Is the only differernce between a DC motor and an AC motor the conenctions? with DC having split ring commutator and AC having 2 slip rings?

5. What would be the ideal materials to build an a motor from?

6. With the AC motor, how would I make split rings that actually work?

I'm sure I'll have more questions soon, so thanks to anyoen who helps me out.

 

[me121]

6. With the AC motor, how would I make split rings that actually work?

AC motor's don't have split rings they have slip rings. i.e. no gap just one ring for each terminal.

 

[henry08]

AC motor's don't have split rings they have slip rings. i.e. no gap just one ring for each terminal.

Sorry I am aware of that, just made an error when posting.

So what material would I make the slip rings from?

 

[namburger]

2. Cork is suitable as it doesn't have a high mass.
Easier for the armature to spin i guess?

 

[me121]

Sorry I am aware of that, just made an error when posting.

So what material would I make the slip rings from?

get a cork and put a ring around it. although you may not get them to fit, and it will wear out your ring.

 

[henry08]

get a cork and put a ring around it. although you may not get them to fit, and it will wear out your ring.

Sorry what exactly do you mean by a ring? As in one you wear on your finger?

Can someone pelase clear up this: With sliprings, must the brushes be physically connected to them or can they just be making conatct with them?

 

[henry08]

How do magnetic fields affect humans? I know about pacemakcers etc, but can they affect a perosn who has no metal inside of them?

 

[me121]

Sorry what exactly do you mean by a ring? As in one you wear on your finger?

I was thinking of any kind of ring, but it probably won't work to well. You could try something like a nut, except the outside is not circular on a nut.

Can someone pelase clear up this: With sliprings, must the brushes be physically connected to them or can they just be making conatct with them?

just making contact with them but not connected in a way that the ring cannot move.

How do magnetic fields affect humans? I know about pacemakcers etc, but can they affect a perosn who has no metal inside of them?

Umm.. I think reasearch is still being done in this area. For example there used to be a syllabus dot point about the affects of magnetic fields created by high voltage power lines on the residents near these main lines. This dot point is no longer in the current syllabus though. However, I think the text book said that there was no affect.

Of course is there was metal in a person, then eddy currents may form and the metal would heat up, obviously this is dangerous, but for a person with no metal i don't think there are many major side effects. But yeah.. i think research is still being done in this area.

 

[henry08]

I tried building the DC motor and the friggin thing won't work!!! The magnets are set up so that they will attract, correct? I.e N - coil - S. I was using a 9V battery, but would a 12V power supply really make that much difference?

 

[me121]

I tried building the DC motor and the friggin thing won't work!!! The magnets are set up so that they will attract, correct? I.e N - coil - S. I was using a 9V battery, but would a 12V power supply really make that much difference?

it should work with a 9V, adding 3V won't make that much a difference. Part of your physics course is to be able to look at your experiment and work out why it didn't work and what you can do to solve it. Lots of things don't work the 1st time, its a learning experience. So use some of your problem solving ability to try to figure it out.

 

[henry08]

Magnets are pretty strong so that is not the problem. Wiring was correct. Weight was minimal. How many loops of wire would be needed (i.e is there a minimum/maximum number?). I made the brushes out of aluminium foil and these were defiantly in contact with the commutator, although how conductive is aluminimum foil?

 

[me121]

How many loops of wire would be needed (i.e is there a minimum/maximum number?).

I think the more the better. As many as you can, without increasing the weight so much that it doesn't work, and keeping it practically possible.

... although how conductive is aluminimum foil?

Try it and see.. using a resistometer, or whatever its called.

 

[henry08]

Unfortunately I still can't get this to work.

 

[uberturtle]

make your motor coil lighter in weight

 

[henry08]

I got it sort of working. I used stogner magents and added mreo coils and when I connect wires up to it it works. Although I can't get the brushes/split ring commutator to work. How small shoudl the split in the comutator be? Mine is about half a mm and still seems too big.

 

[btmtww]

I have to build a DC motor too... and I'm struggling... ( >.<
I did build a simple motor with only 2 magnets, and coil attach to a 9 V battery... in some cases it turns.
But i wonder do i really need a split commutator, brushes and stuff...? Is there any different models of DC motor than the one in Jacar textbook??

 

[Sonata]

go on youtube and look up dc or ac motors, great place for ideas wen i had to build my motor

 

[Martyr-Reb0rn]

i am doing the same as well... i wanted to know where do you get/buy the parts? i been currently looking online for places to buy them, but am turning up empty handed...:mad1: