Australian Facetors' Guild Limited

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.

Regards

Gordon 

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 .

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.

Banggood.com 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.

Regards

Gordon 

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

Cheers