Harrison make some good points. But the Paul I know from this list used to
rave about how fast AutoCAD 12 ran on an Athlon under DOS. DOS is still the
best OS Microsmurf ever made. It boots nearly instantly, is rock stable, no
longer changing. Doesn't start getting flaky after one power cut, etc. So
you can internet surf, but checking your email on your Mill controller never
seemed like such a good idea anyway.
DOS is used by the majority of the PC based controller software, because it
dosn't stop to inspect it's navel for 90ms at random. TurboCNC generates a
clean pulse rate up to ~50kHz (V3.24), with V4 having been optimised for
the Pentium class, it is beta testing at around 100kHz. Running 5tpi
ballscrews, direct drive with 2000 count (qudrature) encoders in 1/10
microstepping mode, this frequency whould be good for rapids to 60
Inches/minute, if thats too slow, the Gecko G340's offer selectable level of
microstepping down to 1:1
The PC based software that best gets around Windows lack of real time
performance is MACH2, which used some very fancy programming to get beneath
the OS. It is limited to 45Khz, and has an excellent reputation.
EMC uses either a red hat 6.xx kernal patch for real time perfomance, or Red
hat 7x with a different kernal patch. It was written with your tax money by
the NIST. It is probably the most powerful of the above, bt is tied with
Linux's learning curve (which you are already familiar with.)
On the near horizon, The Gecko G2003 is the USB device which has just gone
into production. Both Mach2 and TurboCNC software versions are being
developed at present to support this device. The Software will interpret the
G code, and output lower level motion commands, The G2003 will buffer these,
and produce a step/dir pulse stream up to 250Khz, with constant velecity
contouring in real time. Mariss's target price on these 6 Axis devices is
~$300!!!
To get well informed on this stuff, the Geckodrive forum
http://groups.yahoo.com/group/geckodrive/ ,and the CAD_CAM_EDM_DRO groups
are both full of very experience engineers.
http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/
Regards,
Mark
American Flyer wrote:
Paul,
Attached is the serial port info you needed. Sorry it took a while,
I'm just getting used to a new scanner. By the way, I said you
needed 14 amps to drive the motors. That's 14 amps per motor. They
are 1.5hp motors. I don't know what kind of info you got with
your Kasuga. I think you mentioned that you didn't get manuals.
In case you don't already know, they are rated 300 inches per minute
with 0.0002" resolution. Bed is rated for 500 pounds.
Mark,
That G2003 sounds like the right tool for the job! It sounds nearly
identical in function to the system I am just in the process of
designing. The USB port and buffering will of course eliminate any
Windows timing problems. You said it is 6-axis. Does that include
the 80v 20a motor drivers for all six axis, or would you need to
add G320s for each axis? We would still need to either add shaft
encoders or use a resolver to encoder conversion circuit. Analog
devices has an excellent chip for that job. It is a single PLCC
package which requires no additional parts, and it's outputs
emulate a 1024 line quadrature encoder (12 bit total resolution).
Harrison Young
Thanks Harrison. Glad to hear about the AD single chip resolver to
encoder conversion. The thought of changing the resolvers was a little
off putting.
Paul Lamar
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/
Copyright 1998-2003 All world wide rights reserved.