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HB-25, fans questions — Parallax Forums

HB-25, fans questions

RontopiaRontopia Posts: 139
edited 2007-10-31 19:12 in Robotics
I have a pair of HB-25's that I am trying to mount in my bot. the motors are these
http://www.lynxmotion.com/images/data/ghm01.pdf

the question I have is about the fans attached to the HB-25's.. do I really need them? the doc for the motors says that at max load we they will only be pulling 233 mA.. which doesnt make since because the graph above says 1.8 amps.. at any rate, do I really need those fans for this small motor?

the HB's are supposed to be rated for 25 amps and if I were using motors that could pull even half of that I wouldnt even consiter asking this question.

oh and there are 2 of these motors per HB-25. so according to the graph, at the most the motors I have will be pulling 3.6.. I think that is like 14.5% of 25 amps. so do I need the fans for 15 % of max?

thanks guys.

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IC layout designer
Austin Texas

Comments

  • Tom CTom C Posts: 461
    edited 2007-10-21 02:03
    Rontopia,

    Save the HB-25's for that bigger robotic project with the bigger motors (>10A\side) and use a Sabertooth 2X5 RC motor controller to control the GHM-01s.

    I have successfully used the 2X5 with the GHM-04s on a 4WD1 Rover with no problems.

    Just a thought.

    Regards,

    TCIII

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    If you are going to send·a Robot·to save the world, you·better make sure it likes it the way it is!
  • RontopiaRontopia Posts: 139
    edited 2007-10-21 14:19
    thing is.. I already have the HB's with no plans to make another bot with 10 amp motors. not saying it wont happedn someday.. but today this is what I have on hand.

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    IC layout designer
    Austin Texas
  • RontopiaRontopia Posts: 139
    edited 2007-10-22 21:03
    heres a pic

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    IC layout designer
    Austin Texas
    DSCF0281.JPG
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  • RDL2004RDL2004 Posts: 2,554
    edited 2007-10-22 23:26
    I could be wrong, but from looking at the data sheet it appears your motors pull 233 mA at the rated load of 620 g-cm (0.62 Kg-cm) not at the maximum load. They want to be operated down in the lower left area of the graph. This is also where they're most efficient.

    The current draw is at max where everything else (but the load) drops to zero. The maximum current still does not look that high and the HB-25 has thermal overload protection. I would probably give it a try, but I would use small motor fuses on the HB-25s.

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    - Rick
  • RontopiaRontopia Posts: 139
    edited 2007-10-23 00:50
    thats what I was thinking. seems like such a small load


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    IC layout designer
    Austin Texas
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-10-23 18:31
    Rontopia said...
    heres a pic
    Rontopia, looks familiar...

    (forgot attachment)

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    Chris Savage
    Parallax Tech Support


    Post Edited (Chris Savage (Parallax)) : 10/23/2007 9:49:30 PM GMT
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  • RontopiaRontopia Posts: 139
    edited 2007-10-26 02:13
    thats cool, did you finish yours? do you have more pics? and some spec's

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    IC layout designer
    Austin Texas
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-10-30 00:08
    Rontopia,

    Sure I have more pics…This thing is still being tweaked but the specs will be posted once complete. =)

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    Chris Savage
    Parallax Tech Support
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  • Tom CTom C Posts: 461
    edited 2007-10-30 17:26
    Chris,

    I have one of the Thermal Sensor Arrays (TSA) mounted on a Lynxmotion 4WD1 using one of the Parallax PING))) servo brackets and servo.

    I adapted Steve Norris' TSA PIC software to work with a BS2p and presently have the 4WD1 tracking warm bodies around the house.

    Regards,
    TCIII

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    If you are going to send·a Robot·to save the world, you·better make sure it likes it the way it is!
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-10-31 19:12
    Tom, would you share your code with us?

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    Chris Savage
    Parallax Tech Support
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