I think I have dropped a clanger

  1. northwest

    northwest Member

    Messages:
    2,051
    Location:
    Manchester UK
    So, in the big scheme of things, when someone tells me they have it all worked out and a working system, I tend to believe them. This is the second time but I realise it is my fault, don't believe anything until you have tried it yourself. This is for a retrieval system, a small trolley runs up and down a stainless guide wire and is pulled back and forth by a simple 12 volt motor, a Johnson 600 Electric Drill Motor

    Now so far so good, have a real beefy power supply, structure is good, strong and everything installed. Turn the "Low Voltage DC PWM Motor " controller up, press the switch and it all stalls. Give it a bit of a shove and off it goes. Two things I think wrong with the system, the wires supplying the voltage ae "femme" and need to be heavier guage and the controller is just not up to it.

    I welcome suggestions please.
     
  2. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

    Messages:
    16,028
    Location:
    East Yorkshire
    Sounds like you are trying to start it at to low a speed. The motor will not have ant torque, the nudge helps it start
     
    slim_boy_fat and northwest like this.
  3. hotponyshoes Member

    Messages:
    3,377
    Location:
    Somerset. Uk
    Its the controller.
    I bought one of those once. the specs on them are over optimistic by a factor of about 10x.
     
  4. northwest

    northwest Member

    Messages:
    2,051
    Location:
    Manchester UK
    I suspected as much to be honest. Combined with the low torque as @Shox Dr alludes to, What are my options?
     
  5. eddie49 Member

    A true PWM motor controller supplies variable width pulses at the full voltage ( 12v ), so full torque should be available at any speed.
    The linked controller has no power semiconductors on it - it is only rated at 2 Amps. That is not enough - a Johnson drill motor can easily draw 5 or 10 Amps even in a poxy B & D drill. A high-end Makita or DeWalt or Milwaukee drill will draw upwards of 30 Amps.
    Use a much beefier controller, such as these:
    https://www.ebay.co.uk/itm/Dc-12-40...troller-Volt-Regulator-Dimmer-Bn/303773984365
    https://www.ebay.co.uk/itm/20A-DC-1...le-Motor-Speed-Controller-Switch/174376597700
     
    hazzabo, Wallace, Hopefuldave and 2 others like this.
  6. northwest

    northwest Member

    Messages:
    2,051
    Location:
    Manchester UK
    @eddie49 thank you for that.
    Would THIS ONE do as the ones you linked to are in China and I need them pretty sharpish.
     
  7. eddie49 Member

    Yes, that one looks more than adequate as far as power & heatsinks.
    I'm not sure that you can trust the "Location" in eBay listings. Some sellers do have a drop-ship onshore warehouse, others just pretend. Scrolling to the bottom of the listing you suggested shows:

    LONGYANBAIKANGXINXIJISHUYOUXIANGONGSI
    Youmei Jiang
    Xinluoqudongxiaozhen
    Longtengnanlu68hao
    364000 Longyanshi, 福建省
    China
     
    Wallace likes this.
  8. eddie49 Member

  9. northwest

    northwest Member

    Messages:
    2,051
    Location:
    Manchester UK
    The thing is you see, I don't need one, I need eight. At least, probably more.
     
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