Small Motor has me stumped.!

Discussion in 'General Electronics Chat' started by R!f@@, May 2, 2012.

  1. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    Once upon time there was a man who wants to build a CNC.[​IMG]
    Being free lance (AKA Jobless),.....what the ? :eek: I'm not jobless, this is what I chose.. So there?

    Any ways being free lance and all tht getting the parts to build his legendary CNC machine has been a bit difficult.
    It's difficult to build while surviving is because of his current location.
    Which by the way is mm away from a tsunami and even with what we are being ruled with an iron fist. No natural resources, and no factory's either.
    So he uses what ever comes his way. They say other man's junk is another man's gold...who ever said tht said it for a reason and I had to believe cause it happened to me.
    Time passes by and his hard work earns him some gold every now and then.
    Saved gold comes handy in getting things from the near by village which I need like the one shown below
    [​IMG]



    He never gives up. If he sets his mind onto something, he wud do it. What ever it takes or how long it takes.
    He continues to buy things needed for the CNC.
    To start with first comes a spindle motor. The guys in the near by village says that the spindle should be able to run to around 30,000rpm. Which is by the way not easy to come by. So he buys this and stores it.

    This spindle is driven by a VFD and it needs water to cool it. He is so happy he got a good powerful son of a gun for 400 bucks or so.

    As this man is always up to something. So while he is alone, he hunts for things in the junk which cud be gold for him. One day he found a little DC motor inside a broken vacuum cleaner.
    [​IMG]
    It was cracked and he can see the fan blades and motor. So not knowing much and for the fact tht motor might come in handy for something he picks it up and stores it.

    Time passes by, and he gets lonely fro, time to time . When he is lonely funny things starts to happen. He picks up tht small vacuum motor and gives it a 12V to see what happens.

    To his surprise it gave one heck of a whirl. It's like a he has a tornado on his bench.
    So he wanna know it's rpm. and this is was the result

    [​IMG]

    At 12V it gives a RPM of approx 20K.

    And he thinks why do I need a huge and expensive spindle to make his CNC when this little guy can do the same.

    Or is different ?
    Or did I waste my hard earned money for nothing ?

    [​IMG]

    Tell me, dear neighbors ?
     
  2. Markd77

    Senior Member

    Sep 7, 2009
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    Epic post!
    I wonder what the voltage of the vacuum cleaner was, if it was something like 7.2V then the little motor might not produce a tornado for long before it becomes a fireball.
     
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  3. R!f@@

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    U think I wouldn't take tht into account.

    I had the thing in my hand. 12V supplied the air intake helps it to cool down.

    Is it the long run that matters ?

    But still , U got to see the motor for ur self. It's awesome.
     
  4. MrChips

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    Oct 2, 2009
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    Oh dear! So what's the question?
     
  5. R!f@@

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    U got confused chips ?

    Q is could the vacuum motor be used as the CNC Spindle motor?
     
  6. CVMichael

    Senior Member

    Aug 3, 2007
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    The debree from cutting will probably be sucked by the air intake of the motor. I'm not sure if that's a good idea... Unless you attach a long shaft on the rotor?

    But even then, when it's starts cutting, do you think it has the strength to actually do the cut? I think it will stall...
     
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  7. BSomer

    Member

    Dec 28, 2011
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    I agree that the vacuum motor may not have the torque to do the cutting you want when under a load. You could try to test it somehow by putting some sort of side pressure on the motor shaft while running.
     
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  8. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Torque is far more important than RPM.... I'd expect that to be the issue.. along with lifespan of course.. Those spindles are air or water cooled for a reason..

    and you've got a spindle from a machining center.. why would you think about anything else.. Just consider yourself lucky and leave the vacuum motor alone...
     
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  9. spankey666

    Member

    Nov 30, 2011
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    apart from the logistics of getting a chuck to fit and run true under load, i would expect the shaft to bend under x-y load .and the bearings to shag them selves rather quickly. what are you making a cnc for ? just drilling / engraving pcb''s ? the first ones i built used a simple carpentry router motor.
     
  10. R!f@@

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    Aaaah! My neighbors are awake.
    I was feeling lonely in this village.

    Now I understand the problem. WIT (What in tar-nation) was I thinking. [​IMG]

    These times are rather hectic.

    But I gotta tell u, this motor is fast . [​IMG]
     
  11. MrChips

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    Oct 2, 2009
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    How about using an old Dremel tool? It comes with the chuck and everything.
     
    Last edited: May 2, 2012
  12. R!f@@

    Thread Starter AAC Fanatic!

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    U must have missed some of my posts
     
  13. MrChips

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    Oct 2, 2009
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    Maybe I did. What did I miss?
     
  14. mcgyvr

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    dremel tools suck for cnc..the runout/bearing wobble is a big issue..they are far from "precision"..
     
  15. strantor

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    Oct 3, 2010
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    my initial thought was "yeah it spins super fast with just an impeller load, but as soon as you put a load on it, there won't be any power". My second thought was "a small bit scratching away at a PCB is probably less load than spinning an impeller."

    I am officially undecided. I think it's worth trying (before you build the rest of the CNC machine to accommodate the motor).
     
  16. R!f@@

    Thread Starter AAC Fanatic!

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    As Strantor said which I was thinking by the way, the dremel is no different than the vacuum motor.

    And this motor quieter than the dremel which is a big plus for me.

    Now I can make two machines. One big one and one itsy bitsy for PCB making.

    How's that huh ?
     
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