Gecko g540

[Richardtweed]

Hi everyone I'm looking for a bit of help regarding the gecko g540, I have got following cnc,

https://www.ebay.co.uk/itm/1-5KW-CNC-6040-Router-Engraver-3-Axis-Woodworking-Milling-Carving-Machine-DHL/352699767174?epid=1971650033&_trkparms=ispr%3D1&hash=item521e8b5986:g:R-sAAOSwSe1dFcr7

And I'm a complete noob regarding the inner working of these machines so I wanted to know that if I upgraded to the gecko is it a straight forward swap or is it more complicated than that?

[john swift]

going by the photos of the CNC router

To replace the original stepper drivers and breakout board with a G540

you need to find out what motor current the original stepper drivers are set to
very often there is no motor part number or details provided

( you may have to guess and set the current to 2A for example
test the motor when connected to the G540
check the temperature is not over 70C with the axis stepping
note - when the axis is idle the G540 reduces the current
if it gets too hot reduce the current and re test ! )

once you know what the motor current should be
you just need to fit a resistor to each 9 pin plug as described in the Gecko manual
( 1000 ohms per amp upto the maximum or 3500 for 3.5 amps )

more details of the VFD used in the CNC router will be needed
to determin if the VFD can power the G540's PWM to analogue converter
or if you need to add a low power 10 V DC supply

John

[Richardtweed]

Thanks for the help. I'm confused now. I was hoping I would just have to plug it in and away I go lol

[john swift]

without seeing inside the machine the chinese machines look the same outside but
the electronics used inside can be a mix of whats available at the time

a picture of the inside of the control box will help

John

[JAZZCNC]

Thanks for the help. I'm confused now. I was hoping I would just have to plug it in and away I go lol

No need to be confused because it's quite simple to get working. The gecko needs a resistor placing between terminals 1 & 5 to limit the amount of current going to the motor. If don't use this resistor your motor won't run correctly and will over heat.

Now don't stress if don't know your motors current rating because worst case they just run rough and get hot they won't burst into flames or explode or anything daft. However it's best to use a resistor that is close to what you think the motors current rating could be and adjust from there untill they run like you'd expect or want.
A good starting point for that size motor like John mentioned is 2A. So the Resistor calculation is 2.0 x 1000 = 2K This means you need a 2K 5% 1/4watt resistor which you'll find at any decent electronics seller.
You then just connect this resistor betweeh pins 1 & 5 on the G540.

Regards the VFD then to make it work the G540 needs a 10Vdc supply voltage which it can use for the reference voltage(0-10v), this can come from an external power source or as often the case from the +10v output from the VFD.
To get VFD speed control working with G540 you'll make 2 connections coming from the VFD analog connections plus the 10v power source. Often the the Analog connections on the VFD are labeled AGnd & A1. However often these labels change depending on VFD manufacturers but usually it's clear which are analog connections.
So what your looking for is Analog Gnd, Analog 10V(A1), +10V Ref voltage. If your unsure just post a picture of connections on VFD.
This just gives Speed control, you'll also need to use a output from the G540 to Start/Stop the VFD. Often this is done using a Relay.

If the old controller didn't control the speed then you'll need to set some parameters in the VFD to make it work. For this you'll need the Manual or list of parameters for the VFD.

If your unsure of the connections post pictures of the VFD connections and model number.

One last question.? Why G540. While they are neat, they are expensive and there's better options for same or less money.
For same Money you could buy Ethernet based controller that runs much faster/reliable than parallel port and separate drives which give much more scope for upgrading or moving to bigger better machine.