Converting a Manual Mill to a CNC. The Machine Control is written in C# since the AC Servos are not supported by Mach 3 or Mach4.
I bought the ZAY7045FG Rong Fu 45 clone from LatheMaster. I used my trailer lift to lift the mill out of the trailer.
CNC model. Each ball screw is 5:1 reduction. X/Y pulleys have a 2.5:1 reduction and Z has 3.5:1. My design rapids are 150IPM for X/Y and 200 for Z. Acceleration is 0.11G for X/Y and 0.09G for Z. I’ll probably change these latter as I learn CNC machining. All 3 motors are 200V 3000RPM with a rated torque of 0.95Nm and a peak of 2.85Nm.
Drilling oil passage holes for the oil channels.
Gears inside the head
Model of the HL Switch. You can also see the beer tapper table lock.
Oil line routing. X/Y Ball Screws are 20th Century 3/4″ dia. and Z is Kuroda 1″ dia.
A section view. You can see the brake for the Z-axis. It turns out that this is really not required and currently I have the brake removed from the machine during initial use. The machine weights are: Head 170, Column 120, Table 112, Base 110, Swivel 20 and Misc parts 40 pounds.
Front View of the Head.
HL Switch in Carpenter 416 Project 70 Stainless Steel.
Zay on top of the rack cabinet with the control arm in place. The control panel holds the LCD, Kbd, Mouse, VFD control and CNC control box.
Quick release hand crank for Z-axis. The z crank shaft has 2 positions; one for CNC and one for hand cranking. Having the hand crank is extremely nice for belt adjustments, head removal, etc. Just be sure to disengage for CNC use (I already forgot one time).
First Chips. I didn’t have way covers on and it took about an hour to clean this mess.
The control box. I’m not using the Mach3 control. There is a substantial effort in creating a driver. I can use no newer version of Visual Studio than 2003 (as of 2009). Mach 3 requires the use of MFC which I’ve used in the past but prevents use of Visual C++ Express. After reading and understanding most of the documentation for the mach3 plugin development, I cannot be sure how certain things will be implemented such as the ac servo loop, phase advance for field weakening and basic motor commutation. So, I’m limited to Aerotech’s u500 toolkit with minimal programmability.The control box can be removed from the control panel.
Here, you can see the control box sitting in the control panel. The mouse will have a larger pad area attached to the framing sometime in the future. The tooling plate is still under development. I have to decide how to implement sub plates. One sub plate for a M&M motor driven rotary table I have. Another for the 4″ Kurt vise. The quick change tool holder was a little cheaper than the Tormach tool system but the rigidity sucks. I’ll have to see how often that is a factor and use the TTS for heavy loads.
The Westinghouse VFD has a nice removable “operator” that I mounted to the foam board (old signs from flea market). The sign board is nice because I can cut it to size using the shear and it is light and rigid. The load meter is a 0-1V meter that can be driven from the VFD quite easily.
The Dell RAID 600 MHz outperformed my older 2.2 GHz machine on CAD regens and is a pleasure to use. The Aerotech DR500 is very nice but would be better if I didn’t have to make my own schematics. It has an 80VDC bus for the X/Y axes and 160VDC for the spare and Z axis. In the future, I may use (2) U500 cards (I already have) and use a DR500 with dual 160V busses (but using external power supply) and a DR300 with dual 80V buses.
The Y axis motor is mounted partially within the base. I don’t have my beer tapper table locks made yet. The handles are handy for table positioning when the power is off (which is quite often) and I’ll see if handles are really unneeded when I start using the machine.
The VFD is a Westinghouse MA7200. It is a very nice drive with a lot of flexibilty which helps in dealing with the inflexible u500 toolkit. For example: I was able to program 3 of the inputs for an 8 speed control with a lookup table entry for each speed. The u500 has no DAC. An ISA or PCI DAC card would require special stand alone programs or DLL’s that could be called from the u500 toolkit. If I do that, I think I’d rather write the entire control program in C# but for now the u500 toolkit will be fine for a basic intro into CNC (I really need to lean about the machining requirements before embarking on a long programming project-I wanna make some chips now).The large connector is for the 240VAC for the spindle motor. The middle rack cabinet houses the custom electronics for the interface between the DR500 and the VFD, Coolant, Z axis brake and main power.
I could picture spending hours in front of the control, so I made sure that it could be lowered for use from a comfortable chair.
I had a set of 4 roll-n-set casters that can easily handle the weight of the machine.