1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Lathe Motor

Discussion in 'Electrics UK' started by John_S, 14 Nov 2017.

Tags:
  1. John_S

    John_S

    Joined:
    14 Nov 2017
    Messages:
    5
    Thanks Received:
    0
    Country:
    United Kingdom
    Hi, I'm new to diynot, but not new to diy; this is my first post so please forgive me if I say too little or too much.
    I'm trying to restore to working order a mid-1900s wood lathe - good quality and in overall good condition, and one particular problem is the motor. It's non-standard but I don't want to change it unless I have to because it seems in fine condition and fits the bracket on the lathe. It's 1hp single phase 230V AC capacitor start, and although it has a 3-pulley block it runs too fast at 2850rpm rather than preferred 1425rpm.
    Is there any practical way to reduce the speed electrically rather than try to find a mechanical reduction system? A friend said try a Variable Frequency Drive but I want to get a second opinion before I start spending money on a solution that might not work.
    Thanks for reading this.
     
  2. Sponsored Links
  3. Jackrae

    Jackrae

    Joined:
    20 Nov 2012
    Messages:
    2,229
    Thanks Received:
    376
    Location:
    Dumfriesshire
    Country:
    United Kingdom
    Basically there's no "decent" method of reducing the speed of a 1Ph capacitor start motor as it will have a centrifugal switch installed to switch out the capacitor once the motor is up to speed and so must run fast enough to operate this switch. VFDs are excellent but for that you'll need a 3-phase motor with a winding suitable for 230v phase to phase. Your choices are, change motor for 1425 version, install different pulleys, install lay shaft to build in multi belt pulley system or change to a 3-phase motor via a VFD. Note that "domestic" 3-phase output VFD units designed for operation with a 1-phase supply are readily available.
     
    • Thanks Thanks x 1
  4. stillp

    stillp

    Joined:
    21 Sep 2009
    Messages:
    4,496
    Thanks Received:
    338
    Location:
    West Midlands
    Country:
    United Kingdom
    Unlikely that a VFD will help - they are a good solution for 3-phase motors, but won't work with a capacitor start single phase. How many poles is your motor? (How many terminals are in the terminal box)
     
  5. John_S

    John_S

    Joined:
    14 Nov 2017
    Messages:
    5
    Thanks Received:
    0
    Country:
    United Kingdom
    Thanks for the information so far. Beginning to look like I'll need to get a 3ph motor and fresh bracket made. But to answer stillp's question, there are 4 terminals on the motor (excluding earth which is straight to the casing). Does that get us any further?
     
  6. Jackrae

    Jackrae

    Joined:
    20 Nov 2012
    Messages:
    2,229
    Thanks Received:
    376
    Location:
    Dumfriesshire
    Country:
    United Kingdom
  7. Sponsored Links
  8. stillp

    stillp

    Joined:
    21 Sep 2009
    Messages:
    4,496
    Thanks Received:
    338
    Location:
    West Midlands
    Country:
    United Kingdom
    It does, but not in the way you want - it confirms that you cannot change the speed of that motor.
     
  9. conny

    conny

    Joined:
    30 Jun 2008
    Messages:
    13,960
    Thanks Received:
    783
    Location:
    Suffolk
    Country:
    United Kingdom
    Your motor is a 2 pole and you want a 4 pole. There is no way to convert it. You will have to buy a 4 pole or use reduction gearing.
     
    • Like Like x 1
  10. John_S

    John_S

    Joined:
    14 Nov 2017
    Messages:
    5
    Thanks Received:
    0
    Country:
    United Kingdom
    Thank you all for comments & suggestions. I'm working on the results now but it'll doubtless be after Christmas before any useful progress is made.
     
  11. Taylortwocities

    Taylortwocities

    Joined:
    28 Jul 2006
    Messages:
    20,431
    Thanks Received:
    2,113
    Location:
    Oxfordshire
    Country:
    United Kingdom
    Wow, that's one heck of a party that you are going to. Can we all come?
     
  12. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
Loading...

Share This Page