Australian Facetors' Guild Limited

Gemmasta Motor

  • 24 May 2020 5:58 PM
    Message # 8989477
    Deleted user

    Hi Everyone, I just bought a secondhand Gemmasta GE3 and never even got to finish my first stone. :(
    It was intermittently making a loud clunky sound from the motor and in speaking to the seller, I added some oil to the top of the motor and spindle (The motor sits below the platform). It seemed to help and I thought everytning was fine. Today it started making the clunky rattly noise again so I oiled the motor and let it sit for ablout an hour. When I turned it back on, the motor made a loud whirring sound along with the clunks and just stopped. It won't turn back on! :(
    I am assuming that the motor has crked it and the seller is happy to refund me my money but I think I would rather replace the motor... Where on earth would I find one???

  • 25 May 2020 6:21 AM
    Reply # 8990491 on 8989477

    Gemcuts at Ballina is the new manufacturer of Gemmaster.  I don't know if Brian has parts for the GF3, but a phone call to Gemcuts will soon tell you if you can get one or need to retrofit a different motor.  

    I don't know much about the GF3 motor, but if it has brushes, and the windings are not damaged, you may be able to have it repaired.



  • 25 May 2020 10:11 AM
    Reply # 8990696 on 8989477

    This may help you to find someone close to you who can help with your machine.  It is a list of Victoria's Lapidary Groups, scroll down to get to Victoria and see who is near you.

    Last modified: 25 May 2020 10:12 AM | Anonymous member
  • 25 May 2020 12:20 PM
    Reply # 8990800 on 8989477

    Replacing the motor with  a DC motor is a good investment. Many members have been able to do it themselves - if not Gemcuts at Ballina are reliable. I would suggest if the rest of the machine is OK the motor replacement  would be a good move but could cost up to $500 if you have to get someone to do it for you . Are you a member of a Lapidary Club.? I know most Clubs can't operate at the moment but a phone call may put you in touch with someone near you who can give you advice Good luck .

  • 25 May 2020 2:18 PM
    Reply # 8990888 on 8989477
    Anonymous member (Administrator)

    I would as Paul the President of the AFG to send you the modification  

    for 12 Volt upgrade he has done



  • 26 May 2020 7:06 AM
    Reply # 8991996 on 8989477

    Hi Tania,

    John Broadfoot wrote a good article in Facet Talk on replacing a Gemmaster motor with a 12vdc motor.  I can't remember which issue but think it was in the last 2 years. 

    If you go for a 12v conversion, Motion Dynamics in Sydney sell a range of 12v motors and speed controllers called pulse width modulators (PWM).  A 90w 12v motor plus PWM should cost under $100 including parcel post.

    Also a Switch Mode  power supply is a module that wires to the mains and supplies 12v.  They are used in computers and virtually all modern electronics.  They work at high frequencies so the transformer in them is much smaller than a traditional power supply, so they are a fraction of the weight (<500g vs >2kg) and cost. 

    You'll need a power supply with a rating of about double the power of your motor because you will often run the motor at low speed, the motor draws more current at low speed and when starting.

    For a 90w motor, I would buy or build a power supply of 150 to 200w.

    Last time 1 looked a switch mode power supply of 200w cost about $100 from Jayco.  The transformer for a 150w traditional supply costs more than $150 before any of the other parts and labour. has a large range of PWM speed controllers and switch mode supplies pretty cheap, but takes about 6 weeks to deliver so a local source is better.  There is not a lot of price difference between different power switch mode supplies.  Last year a 120 w switch mode supply from Banggood was about $25 and my 300 w supply was about $40.



  • 27 May 2020 12:13 AM
    Reply # 8993137 on 8989477
    Deleted user

    I am having someone look at it from my club and we will sort it from there. I was hoping to get a motor mounted underneath the platform but we will see as a new one is out of my pricerange at thye moment. :)

  • 30 May 2020 8:59 PM
    Reply # 9002786 on 8989477

    Gday Tania

    I have the same machine for a quick fix hunt around dump shops or second hand shops singer sewing machine motors (wernard), bolt strait in not as powerful as the purpose built ones but work okay. Mine runs in anti clockwise direction but I just cut in the leading edge works fine.

    Hope this helps


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