Yeah, Jeff admits that the documentation isn't that good. He and I
traded a lot of e-mails when I was setting up my machine in the
beginning. He likes the GS2 interface (I think that's what it's called)
because that what's on his big mill. What he wrote the software for in
I don't recall what pin the 5 hz PWM signal is on (it's been years since
I set mine up and it just works so I don't have to mess with it) but I
know it's there somewhere. He was actually having a problem with it when
I was setting mine up and had to do some fixing in the code.
My solution to yield a 0-10v isn't that elegant and doesn't produce an
instant change of control voltage to the drive but since I have to
manually change tools there is time for the interface to change the
speed control signal to the drive while I'm changing tools. It involves
a particular op-amp (don't ask me which one and I had to try several)
and a capacitor/resistor pair and a 12.something V supply voltage to get
the full 0-10v swing for the drive. It takes a few seconds to make
fairly large RPM changes but, if I program the speed change to happen
when I'm changing tools, the drive has already set to the new speed
before the tool is replaced with another. It certainly hasn't caused me
You might do yourself a favor and find an old, not good for much else
computer to run your CNC equip. I use old 386 and 486 machines to run my
mills and lathe. There just isn't any need for anything better/faster
when you're working in DOS. My big mill runs on a 386 off a compact
flash card (there is no hard drive). It boots in about 10 seconds and
there is nothing on the drive (the CF card) but the basic DOS files and
the program and NC files. It's wonderful.
Good luck. If you need some info on my op-amp speed control I can at
least get you the version of op-amp and maybe the resistor/capacitor
combo I used. I should have made a schematic when I built it but I was
just wanting to get it working.
On 12/2/2010 4:27 AM, Keith Cockburn wrote:
> Hi Tracy
> Thanks for the info, will be trying Zeus PWM soon. From the documentation there is no mention of PWM however but when I tried the demo pin is defined coolant2 /PWM. This was after having a tussle to get pure DOS going with dual boot from NT, with a 6G disc and up to F hardrive letters in DOS, G is not available for CD !!
> I have sawn up an old computer board for the parallel skt and will try ASP to get the speed of a washing machine motor under computer control.
> Best Regards Keith