On 9/23/23 18:10, John Dammeyer wrote:
Oops. Forgot to include my numbers:
[JOINT_3]
TYPE = ANGULAR
HOME = 0.0
FERROR = 1
MIN_FERROR = 0.25
MAX_VELOCITY = 180.0
MAX_ACCELERATION = 720.0
# The values below should be 25% larger than MAX_VELOCITY and MAX_ACCELERATION
# If using BACKLASH compensation STEPGEN_MAXACCEL should be 100% larger.
STEPGEN_MAXVEL = 225.00
STEPGEN_MAXACCEL = 900.00
P = 1000.0
I = 0.0
D = 0.0
FF0 = 0.0
FF1 = 1.0
FF2 = 0.0
BIAS = 0.0
DEADBAND = 0.0
MAX_OUTPUT = 0.0
And if I give it an G0 A1440 it does 4 revolutions at an indicated velocity of
10800.
John
First, my numbers are for a nema-23 3 phase stepper servo, a closed loop
setup with an optical encoder on the rear of the motor that feeds the
controller. All lcnc does is feed it steps.
This has 3 advantages. 1. If it loses home for any reason, it can stop
lcnc in the nest millisecond. Well tested but has never occurred in use.
2. it uses the error signal from it own internal a/b decoder as the
currant control for motor current, Unless you are driving them at
rediculous speeds, very little motor heat. 3. I use them at supply
voltages approaching the 50 volt controller rating, in the case we're
discussing I have a 5/1 worm driving the output chuck so at 300 full
steps so its 1500 steps for one turn of the worm shaft. At my current
settings its doing 864000 degrees a minute, or 40 rpm's. It also 2400
rpms at the motor armature, well above the torque fade for the 24 volt
versions. And a full stop after I remove my finger from the keyboard is
maybe 5 degrees. I have one of my vise screws mounted, can g0 a500,000
and burn my hands trying to stop the 50mm diameter screw while the dro
is reporting 864000 degrees/minute velocity. A 40 rpm A axis for under
$200 including a 48 volt 3.3 amp supply to run it. I think I'll keep
it. Oh, there is not a PID in the signal path. PID's are for slower stuff.
Me and the new PID are having a big argument. The autotune does not
work for me, and it left my bs-1 quietly hunting a fraction of a degree
& wiped out a $125 motor in the 3 minutes I was looking for the odd
noise, it was that quiet.
Take care and stay well, John.
[...]
Cheers, Gene Heskett.
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/>
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