building a motor (1 Viewer)

[sexandwetex]

i've built a motor. the only problem being that IT DOESNT FRICKIN WORK!!!!!!:burn:
i was wondering whether some1 could help me with my dillemma with suggestions and the like. please and thankyou.

 

[Riviet]

It's a DC motor right?

There are many things that can go wrong in a motor, it took me quite a long time to get mine working.

Maybe you could post up a picture of your motor.

 

[sexandwetex]

ok. heres the photo. theoretically i think i should work because the current goes to the coil but it doesnt. at all. not a twitch. and yeah its dc.

 

[insert-username]

You might not have enough current just out of the battery - we connected ours to a power pack for some more juice. You can also try strengthening the magnetic field (we had two sets of three bar magnets taped together for a nice strong field). Also, you may need to hold the connections on the commutator together - we found that ours wouldn't go unless we physically held the connections in tight.

Apart from that, make sure the axle can spin freely, that you've sanded the ends of the wires, etc. Tinker with the design as you go to make sure everything fits the theory as best as possible. Don't worry if you don't get it first go - they are fiddly to make and we needed three periods to get ours spinning well. Good luck.


I_F

 

[Eggbruce]

also make sure you're coil is completely surrounded by a magnetic field. your magnets often need to encompass all the coil, without it many stuff up.

 

[Laids]

hi, when we made our motors, i found that u had to have a large amount of loops in ur coil, (mine was 50 loops but probly did not need this many), and when theiur are so many loops a large amount of current is required, the voltage however is not very important, i suggest conecting ur motor to a power pack.

By making a larger coil and using much higher current, u dont have to have the motor as perfectly balanced and can have more room for error, but the motor still work, the smaller and less power you use, the more accurate and exact you need to be with everything you do

 

[kokuy]

Hey guys I m working on a project can one of you give me a sick design of DC motors. It doesnt have to like strong but easy to build and powerful enough to pick up 5~10 paper clip. Oh yeah i m still in high school and i m 20 i couldn't graduate for 3 years because of this stubid project~!!! (jokes)

 

[sammyd8]

yeah i no ur problem bozo ur gay

 

[sammyd8]

my physics teacher told me to check that all of the coils were wraped around corectly and that the brushes are in correct working order. she then said that u should place it in a large bath of water and then hop in the bath and turn the motor on. she also sugested using an existing motor found around the house such as ur mums vibrator motor.

 

[jeniii]

RivietIt's a DC motor right?

There are many things that can go wrong in a motor, it took me quite a long time to get mine working.



how long dus it take?? =/

our assesment for next year.. make motor from scratch under exam conditions within 2 hours T__T

gotta get own equipment .. can i get help for wat to buy? like under the list of tools, it tells us "any amounts of iron" *is lost*

 

[Riviet]

It took me an hour or so to set up everything and about 15 minutes fiddling and testing to see if the motor worked. 2 hrs is enough time.

I used a flat piece of foam as the base/support and poke 2 pairs of wooden sticks in an X shape to place the axle on top. A bendy metal thing was used for the split ring commutator. Try to make the motor as light as possible and keep the weight balanced on all sides of the motor to allow for a smooth spinning action.

 

[jeniii]

ahk. thats not too bad then. i tried making one today with wires from broken earphones, bobby pins and paperclips. dint work. =/

um .. bursting with more questions after reading text book ><

we have to use electromagnets rite. so dus that mean another separate coil thing? like theres already a coil that rotates. so i have to make a solenoid with another coil? so one coil that rotates and another coil with an iron inside that is placed near the first one?

did u use sum carbon/graphite thing for a brush? and the commutator.. so this is wat i get .. as the brush sets the charge, the commutator spins. therefore the charge affecting the wire changes depending on whether the commutator is touching positive or negative. is that rite?

"A bendy metal thing was used for the split ring commutator" so it can be any piece of metal connected to powersource?

one of the requirements is for motor to be 'self starting'. so if i turn it on. it moves by itself .. is that it

/=]

 

[alcalder]

we have to use electromagnets rite. so dus that mean another separate coil thing? like theres already a coil that rotates. so i have to make a solenoid with another coil? so one coil that rotates and another coil with an iron inside that is placed near the first one?

Yes, the electromagnet around the rotating coil is another coil solenoid.

did u use sum carbon/graphite thing for a brush? and the commutator.. so this is wat i get .. as the brush sets the charge, the commutator spins. therefore the charge affecting the wire changes depending on whether the commutator is touching positive or negative. is that rite?

Exactly. The direction of the current flow depends on whether you have negative or positive touching the end of the wire. Make sure you have the commutator swicth over in the right place of the turning coil (ie when the plane of the coil is perpendicular to the magnetic field).

"A bendy metal thing was used for the split ring commutator" so it can be any piece of metal connected to powersource?

The bendy metal thing as the commutator MUST be connected to the rotating coil. It is the brushes that are connected directly to the power source.

one of the requirements is for motor to be 'self starting'. so if i turn it on. it moves by itself .. is that it

Yep, that's right. So, you have to think how that is going to be achieved. Will it just happen?

 

[Forbidden.]

Are you a lenient marker with Physics tests, exams or assessments ?

 

[alcalder]

Are you a lenient marker with Physics tests, exams or assessments ?

Am I a lenient marker??

I'm a fair marker. If there are criteria set (which there are these days) it is fairly easy to say which is worth a certain number of marks. However, there is also no reason to demoralise a class of Physics students just for the sake of making Physics seem hard.

I ask myself: "what do I want to test on this exam/assignment/test?" and then limit my marking to that. eg. recently I marked an assignment that was testing just whether the students had correctly listened to and extracted certain information from a television show (Year 7 science work). My criteria did not include correct spelling nor grammar. One student, who is probably dislexic, still showed he could extract the correct information (although interpreting what he had written was interesting) and he achieved full marks despite the messy nature of what he had written - no correct spelling and letters incorrectly written. He had achieved the set task.

So, if I were marking the Motor Construction, I would have marking criteria that looks at design, correct implementation, effective operation and so on.

Always ask your teacher for the marking criteria and work towards it, making sure you fulfil all the criteria (and if SPAG is a criteria, then do it right - Spelling, Punctuation And Grammer - but try and do it right always).

 

[Forbidden.]

Am I a lenient marker??

I'm a fair marker. If there are criteria set (which there are these days) it is fairly easy to say which is worth a certain number of marks. However, there is also no reason to demoralise a class of Physics students just for the sake of making Physics seem hard.

I ask myself: "what do I want to test on this exam/assignment/test?" and then limit my marking to that. eg. recently I marked an assignment that was testing just whether the students had correctly listened to and extracted certain information from a television show (Year 7 science work). My criteria did not include correct spelling nor grammar. One student, who is probably dislexic, still showed he could extract the correct information (although interpreting what he had written was interesting) and he achieved full marks despite the messy nature of what he had written - no correct spelling and letters incorrectly written. He had achieved the set task.

So, if I were marking the Motor Construction, I would have marking criteria that looks at design, correct implementation, effective operation and so on.

Always ask your teacher for the marking criteria and work towards it, making sure you fulfil all the criteria (and if SPAG is a criteria, then do it right - Spelling, Punctuation And Grammer - but try and do it right always).

So you aren't my friend's Physics teacher then, because his Physics teacher teaches only at a senior secondary school (i.e Year 11 & 12 only), is a lenient marker and is "lazy" to put it directly.

I thought the words are spelt dyslexic and grammar.
Anyway what I am not happy about my Physics teacher is the extra-curricular stuff he often teaches in class such as the Maths Extension 1 trig stuff like sin(A+B) = sin (A+B)=sin A cos B + cos A sin B and sin2A = 2 sinA cosA
Most of us are able to diffrentiate the equations of projectile motion, but the poor General Maths student (who is currently the worst in the class) can't.

I also take his comment "Physics is easy" as quite sarcastic and biased (from our schools frame of reference), because our Physics class consists of only 12 male students where most of them are the the more academically-inspired types and no regular Year 11 student would dare study Physics , based on popular myth Physics is hard, while on the other hand my friend's school has 6 Physics classes, a far cry to ours (note he goes to a part-selecive school).

 

[jeniii]

im trying to build a DC motor with a 4 phase split ring commutator but i dont know how to wind the wire around my ammuture coil or how to connect the ends of the coil to the split ring face. since there are 4 faces i have to cut my wire into 2 rite?



or can you just tell me how to make a 2 split ring commutator self starting.



building a motor is such a guy thing =.= my skin feels all rough and flaky from sanding and sawing wood =[

 

[samtam]

Its almost impossible to get the electromagnets strong enough to work. I used a whole spool (~70m) of 0.2mm enamel copper wire on 2 soft iron cores and it's about 1/20 the strength of my permanent magnet. And I only just got it working with my permanent magnets.

I'm gonna talk to my science teacher tomorrow and discuss how this probably isn't possible/practical with electromagnets.

btw, if you're jeniii from BHHS, you can help me talk to him tomorrow XD

 

[alcalder]

I thought the words are spelt dyslexic and grammar.

OK, yes.

Anyway what I am not happy about my Physics teacher is the extra-curricular stuff he often teaches in class such as the Maths Extension 1 trig stuff like sin(A+B) = sin (A+B)=sin A cos B + cos A sin B and sin2A = 2 sinA cosA
Most of us are able to diffrentiate the equations of projectile motion, but the poor General Maths student (who is currently the worst in the class) can't.

I also take his comment "Physics is easy" as quite sarcastic and biased (from our schools frame of reference), because our Physics class consists of only 12 male students where most of them are the the more academically-inspired types and no regular Year 11 student would dare study Physics , based on popular myth Physics is hard, while on the other hand my friend's school has 6 Physics classes, a far cry to ours (note he goes to a part-selecive school).

Physics is not easy and IMHO with the addition of needing to write so much now it has been made trickier for those who would have done Physics in the past - the maths/science heads who have difficulty with english ie me. BUT, taught correctly and in an interesting manner Physics can be FUN and therefore not such a chore.

And with the electromagnet - how strong do you need it? MY son made a great Electromagnet with a few turns of wire around a nail and a 9V battery. It could pick up quite a few paper clips.

 

[jeniii]

@sam =O whered u get soft iron core from. no shop (jaycar/dicksmith/mitre10/bunnings) has a clue. and apprenty ms J said theres absolutly NO way they will change the criteria to permament magnets.

@ alcalder: an electromagnet strong enough to turn a dodgy home made coil of wire on a bamboo skewer

9v batt are soo crap! (ok .. theyre 1 dollar ones from the reject shop) and it only had 5MILIamps. the 6v batt (also from reject shop) had like 10 times more current. someone try connecting 5of them in parralel and tell me if it works .. =D

omg.. the other day.. smoke started coming out of my cork coil amuture thing O.O if i leave it long enuf.. will it catch on fire =D

edit: btw instead of me testing them all, does anyone know which type of battery gives out the most current - that has not more than 9 volts