On 2010-06-13, Wes wrote:
Roger, I thought about G code, but not too much. I know that I can
handle G code and generate it in fun way with perl and such.

I'm sure you can. I suspect your G code is going to be heavy into
using macro functionality since you are a coder. My first
production PLC program didn't look like most PLC programs because I
wrote it like a guy used to procedural languages. The plant
electrician thought my approach was a bit weird.

I don't know yet Wes. Maybe I will make G codes with procedural
languages. If so, then G codes will look kind of dumb.


My main concern right now is producing a system that is SAFE to
operate (properly takes all safety inputs into account) and that is
properly designed to be usable and not weird. Then I will try to make
sure that it is accurate by defining various parameters correctly.

Make sure you have e-stops where you can get at them. Over travel
limit switches to protect the axes. Sane parameters and circuitry
so if the control system determines there is a problem, it can force
an e-stop.


I agree. I think that my plans are solidifying a little bit.

My first priority is installing encoders, and hooking them up to Jon's
PPMC box and that, to CNC. The axes would not be powered by servo
drives.

I will make up a little mill control, from a little DC power supply,
X-Y-Z selector, and On-Off-On switch, hooked up to the servos.

I would operate this control manually by hand.

With that, the mill will be manual controlled and will use PPMC as
just a DRO display.

The objective here would be to see if all the iron works, to debug all
estop logic, limit switches, inhibits, etc. The mill will be 100%
manually operated, but with the PC and PPMC working as a DRO.

Then I will try to fit it with a VFD.

At that point, it could be used for milling, like a regular Bridgeport.

I would then make sure that all auxiliary things run correctly, like
speed control air valves, coolant etc.

The next step would be to hook up the drive power supply (military
battery charger) and AMC servo drives and imlpement proper automatic
control.

The advantage of this is that I could spend a couple of weeks
debugging this mill's safety and other functions, being almost 100%
safe due to manual control of the positioning.

i