Re: [CAD_CAM_EDM_DRO] Bridgeport CNC Mill???

"hanermo" - CNC 6-axis Designs wrote:

>
> Corrected ... servo update rate at 1 kHz is enough BUT,
> EMC sw servo control is not (as teh max rate is far too low in software).
> So, again, it is not by any means necessarily clear-cut, simple, easy
> and or cheap.
>

Huh? You seem to be contradicting yourself. EMC2, by default closes
the servo loop at
a 1 KHz rate, but higher rates can be selected by changing one line in
the ini file. 10 KHz
is probably achievable on most hardware, some can be selected for 20 KHz.

WHAT "max rate" exactly, is "far too low" on EMC? I just mentioned that
a torture
test I did showed over 750 G-code blocks per second on a 600 MHz Pentium
III, it
certainly would be higher on a modern CPU. Do you have a figure for Mach?
I could send you the program if you'd like to compare.

>> Higher resolution means that your
>> encoder counter hardware has to run faster. Both Mesa and Jon's hardware
>> will count at several MHz.
>>
>>
> Yes they will.
> Neither is a recognised industrial supplier, with compatible funcionally
> identical hw available from several sources.
>

Fine, if you MUST have Fanuc, Kollmorgen or Allen-Bradley, pay their
prices and don't
complain to us when a 3-axis setup runs to $50,000. And, if you try to
swap out a Fanuc
servo amp with a Kollmorgen, I suspect you will find out the plugs don't
just plug
right in. There WILL be some reconfiguring and adapting required.

> Advanced is anything on a lathe with multiple axes;
> more than 4 axis mill,
> with servo-indexed spindles,
> live tooling,
> multiple spindles,
> multiple turrets
> and so on

You really need to check out what Stuart Stevenson has done with his
Cincinnatti 5-axis
machine. He has some interesting Youtube videos of it doing a ball test
showing the
accuracy of 5-axis coordinated motion. I really don't think you can do
this on Mach.
And, I know you can't do the kinematics corrections in Mach that he has
done to
correct for all the inaccuracies in the construction and installation of
the machine.

Jon