Roskrow,
Your inverter manual is available for download here (E300, from Sunfar):
http://www.kunaimpex.com/admin/images/gallery/pdf/806263833.pdfremember I know absolutely nothing about the GX6060 or the leafboy motion controller, but I'll try to give some suggestions given your first request was how do I bypass mach3 and test the spindle, hence there is a fair bit of presumption in this post (you've also noted the GX6060 came pre-wired).
Leafboy manual here:
http://leafboy77.com/files/USB_Motion_Card_AKZ250_Manual_v1.17_CN-EN20121102.pdf.zipOk, the leafboy motion controller outputs a PWM (pulse Width Modulation signal from two of its pins to the spindle).... poor diagram in the manual (pdf page 8/80), two others on 58/80 and 59/80....
Looking at your inverter manual, its controlled via a 0-10v analogue input signal (inverter manual pdf pages 13/42 and 15/42).....
key words analogue and 0-10v (inverter), and PWM 0-5v (leafboy)
Although a PWM signal can look a bit like an analogue signal with a voltmeter and mimic it... its not analogue.... hence unless they have done it properly you may experience not quite the linear profile you thought later on.... but it may work (again no leafboy expert).
within the leafboy manual there is a "hack" to get it to run with a 0-10v analogue signal on page 59/80
there is a clearer (non Chinese) image here:
http://www.mycncuk.com/attachment.php?attachmentid=13647&stc=1there is a bit of a discussion here although its not about your inverter some of the consideration should be the same with the signal (analogue is not the same as PWM in simple terms without doing something to it).
http://www.mycncuk.com/threads/7992-Denford-Novamill-Mach3-conversionOk....
to get your spindle to work in manual mode (as we'll presume it came pre-setup to run with mach3 and pre-wired)...
Have a look at pdf pages 21 & 22 of the inverter manual
as you can see "F0:0" provides the spindle control signal .... 0-10v external or from the potentiometer ... by selecting either 0, 1, 2 or 3 .... the default setting should be 3.... but as your machine probably came pre-configured they probably changed it to "1" ... external 0-10v control.
The same the "F0:2"... it is probably set to "1"... changing it to "0" should bring the control function back to the inverter keypad so you can control the spindle without mach3.
Note.... the F0:2 I say should as they are not clear about the 1st and second digits.... hence have a look at what the F0:2 number is before changing it
Best advice.... write down all settings before you change any....
Access to the functions is listed on pdf pages 17 and 18
And the "simple" (non mach3) operation is listed on page 19 & 20.
Rob