CNC 3020 USB

Finally, after so much time spent in thinking, I’ve bought a Chinese CNC. I’ve choosed the model “3020T USB” from CNCEST manufacturer because it have a USB port; other cnc’s need a pc with parallel port and I have no pc with it! I’ve just a MacBook PRO with Windoze7 running on Parallels…it must work!  I’ve bought it from ebay seller “top5zoom” that shipped it from Germany via DHL for free.

The machine arrived into two big boxes. The packaging was made very well with 5cm soft plastic foam that protect and stabilize the machine into the box. The total weight of the two parcels was 35kg!!!

The machine is very noisy during operation. I’ve enclosed it in thick foam boards to reduce it.

The first thing to do after unboxing was assemble it. Just screw in 4 power supply connectors. Simple and easy. The second was check the ball screws,all 3 axes are moved on ball screw, and greas it with heavy aeronautical grease “Anderol” from US Army surplus. Probably standard grease will do the job but I’ve preferred my military grease.

Power on!

At first I’ve found that the VFD controllor had a corrupted configuration. Following the first part of this post that I’ve found on a forum, thanks to user “gmungas”, I could have it running well.

This is the VFD controller.

PRT-E1500W vfd settings

The post:

"I finally figured out the VFD and Mach3 software settings for my 1.5 kW, 110Vac, 400Hz Spindle with the PRT-E1500W VFD in order to run the spindle either in manual mode or with PWM control through the PC. Here's the procedure I used. (Note I didn't change the 220V setting to 110V in the VFD since there isn't a mechanism for generating higher voltage than the VFD supply and it doesn't appear to be necessary, but this should be vetted by another party (CHIMERA1960?) prior to long duration running).
 1) Reset the VFD to factory settings
 a) Set D001 to 1 (may be able to skip this step)
 b) Set D176 to 1 and press Func (this resets VFD to factory settings)
 2) Reset the VFD to 400Hz max operating frequency rather than the 50Hz default:
 a) Set D002 to 400 (need to set this before D000)
 b) Set D000 to 400
 c) Set D003 to 400
 d) Set D009 to 400 
 e) Set D021 to 400 
 f) Set D093 to 400
 3) Set VFD to receive input frequency setting for spindle throttle control from the AVI terminal:
 a) Set D031 to 1
 4) OPTIONAL but I would recommend for additional debug/safety reasons: Set VFD to allow manual spindle "stop" from terminal even when running from PC
 5) OPTIONAL: Set AVI terminal to readout spindle rpm instead of VFD frequency:
 a) Set D039 to 1
 6) To run the spindle manually with variable speed directly from the AVI terminal:
 a) Set D032 to 0
 b) Make sure switch next to AVI terminal is set to "Manually"
 b) Use AVI "Pot Dial" to set spindle rpm
 c) Use AVI "Run" to start spindle
 d) Use AVI "Stop" to stop spindle or turn down Pot Dial to 0
 7) To run the spindle from the PC (note the PWM signal from Mach3 adjusts the setting of the AVI terminal as if it were the VFD Pot. The PWM signal is NOT going directly to the spindle motor):
 a) Make sure you have the right Port/Pin settings in Mach3 (see example settings below)
 b) Set D032 to 1
 c) Make sure switch next to PRT is set to "PC"
 d) Very important: On Mach3 User Panel, make sure you select and input the max spindle speed (i.e. 24000).
 e) Select the actual spindle speed by adjusting up/down arrows or dragging the column up/down for relative speed setting changes.
 f) Use "Spindle CW F5" button or "F5" to toggle turning the spindle on/of
 Mach3 software settings that work for my spindle and wiring configuration (if you have an issue with the X,Y,Z position controller settings let me know, but I think most don't have this issue):
 A) Ports/Pins
 1) Port Setup and Axis Selection
 i) Port #1 Enabled
 ii) Kernel Speed Set to 35000 Hz (this worked for my 2.9 GHz desktop controller, but you may need to use the lower 25000 Hz setting for slower machines)
 2) Motor Outputs
 i) Spindle Enabled = Active
 ii) Spindle Step Pin# = 1
 iii) Spindle Dir Pin# = 0
 iv) Dir LowActive = Active
 v) Step Low Active = Active
 vi) Spindle Step Port = 1
 vii) Dir Port = 0
 3) Input Signals
 i) EStop Enabled = Active
 ii) EStop Port = 1
 iii) EStop Pin Number = 10
 iv) EStop Active Low = Active
 v) EStop Emulated = Inactive
 4) Output Signals
 i) Enable1 Enabled = Active
 ii) Enable1 Port# = 1
 iii) Enable1 Pin Number = 14
 iv) Enable1 Active Low = Active or Inactive
 iv) Output#1 Enabled = Active
 v) Output#1 Port# = 1
 vi) Output#1 Pin Number = 17 (this should NOT be the Motor Output Step Pin (e.g. Pin #1 in my configuration) as may be indicated in some of the user manuals)
 vii) Output#1 Active Low = Inactive (important to make sure Spindle is On when Mach3 Toggle Switch is on. May need to change this setting if switch appears to be operating backwards)
 5) Spindle Setup
 i) Select "Use Spindle Motor Output"
 ii) Select "PWM Control"
 iii) Input "PWMBase Freq." (I used 421)
 iv) Input "Minimum PWM" ( I used 0%)
 B) Pulley Selection
 i) Pulley Number 4
 ii) Min Speed = 0
 iii) Max Speed = 24000
 iv) Ratio = 1
 Good luck! Hope this helps!"

The machine comes with some accessories:

  • 4th axis with it’s accessories
  • USB cable – power chord
  • fixing screws – clamps
  • some wrenches
  • 4 flute mills
This is the 4th axis with it’s wrench

The 4th axis after an hevy greasing works well. It’s not precisely machined but it works.

Mill bits

The spindle is water cooled, included into the package there is a water pum. I’ve made this super-simple water cooling system. It’s work without any problem but is ugly!

Water cooling

I’ve tested this CNC with Mach3 software. The setup is very simple. Just download USB 4 axis 3020 and unzip it into your Mach3 main folder, typically “C:\Mach3”. Pay attention there is a licence file in it supplied by the CNC’s seller, probably is fake/illegal/cracked/cloned but is working. Buy a licence of Mach3 if you like it. The VFD uses “RnRmotion.dll plugin”. Select it if Mach3 ask you during startup wich plugin must be used for motion control. With the supplied package you obtain a correct motor/step contiguration so there is no need to change it.

More testing/video soon… stay tuned!