Hi,
I will study it a bit later however why only 5000cpr are required (seems low) ?
If the effective cpr is 5000 and the distance traveled is 5mm ( the pitch of the screw) in one revolution:
resolution=5/5000
=0.001 mm
=1um
As I posted earlier 1um resolution is entirely adequate. I could have much more resolution but why?
Does delta encoder have any some special encoding (X4?).
Yes, in fact the B2 series encoder has 40,000 lines which (x4) means 160,000cpr. The numerator and denominator
of the electronic gear ratio are based on 160,000. No need to confuse yourself with lines vs counts per rev.
You can program the drive to output a simulated encoder of anywhere from 4 lines to 40,000 lines should you require an
encoder output stream, that does not affect the basic encoder built into the servo nor the numerator/denominator
of the gear ratio.
Lets imagine that you wanted the max resolution that the servo can achieve, in this case 160,000 cpr or
8.1 arc sec (31nm if direct coupled to a 5mm pitch screw) then at 3000 rpm the required step rate would be:
step rate=160,000 x 3000
=480 MHz
That is well in excess of the step rate of the ESS and you could never signal a servo drive down a cable at that
frequency anyway.
Note that the B2 series Delta servos can be signaled at 4Mhz in its highspeed differential mode. But still the question
is why bother? I have used my existing mini-mill for years with a 1um resolution and never had need for finer resolution
so why do I require more with this new mill......I don't. That decision has made the design of the signaling that much simpler.
I am not familiar with Argon but Yaskawa is of course justifiably famous.......and about twice to three times the price and quite
frankly, they are not anything like two to three times as good.
There is only one instance that I would consider Yaskawa an that is if I required Ethercat, Yaskawa has a market leading position
in Ethercat capable servos. Mach4 at this time is natively step/direction. There is a current development by Kingstar/Interval Zero
that has made Mach4 Ethercat capable but it is not yet mainstream. I have, at this time, no need to step up to Ethercat so
why bother with (expensive) Yaskawa servos?
Craig