CNC mill

• Research and preparation  - this posting
• Assembly
  
• Software setup
• 4th axis - TODO 
• RS485 spindle control

Just ordered myself a chinese CNC mill. Model "YOOCNC 6040Z+S80" from "carving-cnc".
I thought GoCNC first but they use threaded rods instead of even trapezoidal spindles and employ Dremel and Proxxon as spindles. This one used a ballscrew and comes with a water cooled 1.5KW drive.

I know, it won't be a high end device. It can barely do metal but it should be sufficient for light wood, acrylic and wax with it's supplied 1.5KW spindle.

So far I found out that I have to check the following:

1. Check for loose bolts and righten everything down.
2. Mill a perfectly flat bed. 
3. Check grounding and cooling on all electronics.
4. Replace stepper-wires with shielded ones.  Test all stepper wires for broken ones.
5. Add 2 end stops for each axis. (pins 11,12,13) with a 500 Ohm resistor from +5V to pin 15
6. Add a probe input (pin 15)
7. Insulate the spindle from the case to avoir random interference into the x,y,z steppers. 
8. Check heatsinke for the possibility of them creating shorts due to not being deburred. 
9. "I then read the download manual that came from site and all configurations seemed correct, until I downloaded a Mach3 manual which show that in the configurations the dir pulse is active high and should be active low, note when you change this you will need to reverse direction of motor, as it changes direction." 
10. Add a connector for a probe. 
11. Replace the water hose and pump. Check the original hose for kinks.

The plan is to  use this for parts that are difficult to do on the 3D printers or require materials I can't print or print molds for.
I'll post about the progress and issues with this machine under the tag "CNC", so others can read up on how these machines perform and where they fall short.

• manufacturer website
• Video of a YooCNC at Nottingham hacker space 
• Wiki of Nottingham hacker space 
• Software (g-code to; steps via parallel port) I should read up on 

• CamBam looks line to start with but doesn't support the 4th (rotation) axis.
• deskcnc (how to buy just the software?) and
• deskproto (995eur for multi-axis version) have a 30 day trial and can do this 
• MecSoft FreeMILL seems to be limited to carthesian 3 axis but is free
• PyCAM also 
• GcodeGenerator runs from inside Blender 
• maybe enhance this Java software to create 4 axis g-code for following the surface normal 

• added end switches
• Videos about modding the 6040 control box  
• Blog post leading to a solution for the random stepper movements. 
• settings 300steps/rev. 1500mm/min(Z=500mm/min), 300mm/s^2(Z=150), 10us steps/pulse, derr/puls=5
• Video about using a probe with the PCB
• jewelers forum 
• line card analysed for shortcomings. 
• spindle controller manual

Things to get:

• PC with parallel port (maybe a touchscreen pc) and RS485 port for spindle control
• some more milling bits (here or here or here)
• planar metal milling bit to even the work-surface
• flexible, thick, shielded 4-core wire for the steppers (ebay may be cheaper despite customs). steppers=1mm/18 gauge 4 core, spindle=1,5mm/16 gauge 3 core (perhaps these and these or from here)
• additional fans
• stable 4-pin connectors for the steppers
• Gecko G540 and a power supply. 
• machinable wax for first low-risk tests ( here or here or this with this with some more tools)

timeline:
2012-08-08 ordered and payed via paypal (so I can dispute and get my money back if they don't ship)
2012-08-08 no order confirmation but a hand written email with details about the shipping process and customs
2012-08-16 Machine arrived !!!

specs:

X,Y,Z Working area：	580×380×60mm
Max. Feeding height：	≤100mm
Outside dimension：	880×660×520mm
Table size：	745×480mm
Lathe structure：	6061/6063 Aluminium alloy
Stepping motor：	two-phase 57/3A (2.2-2.5mH inductance)
Drive unit：	1605 Ball screw
Sliding unit:：	Chromeplate shaft
Maximum speed：	0-4000mm/min
Engraving speed：	300-3000mm/min
Repeat positioning Accuracy：	0.05mm
Spindle：	1500W VFD spindle motor
Spindle speed：	24000rpm
Cutting tool-holder：	ER11-A: 6mm and 3.175mm( =1/8" )
Interface：	Parallel port
Software Compatability：	Mach3/Emc2,(Type3,Wentai, ArtCAM)
Command code：	G code/.nc/.ncc/.tab/.txt
Weight：	55kg