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Glad I'm not the only one loosing 100 IQ points when setting up homing......your description is perfect lol.


If your homing switch is by the operator
Set y max to zero
Set y min to -145
Leave default homing.
Set your 0,0 in g54 after startup.

The above sets 0,0 to the upper left. Getting it to the lower left isn't possible without flipping an axis (right hand rule problems).....hence the g54 zero after boot up.


If your homing switch is away from the operator....this one gets rough.
Same idea as above
Y max is now 145
Ymin is zero
All homing is inverted. (Direction, latch, etc)
Then set the y offset to -145 and it should home then drive back to the operator

This is from memory so it might be wrong....but that's the general idea. I make sure my axis is moving in the correct direction, if it's not I flip it electrically, not in software, to make this easier.

While attempting to tune some servo motors, I see pcw often recommends setting the ouput_scale in machine units per second at 10v.
I like this idea, but am having trouble implementing it on my retrofit.
Machine units are inch.
These are old servos being controlled by a mesa 7i97t using analog 10v.
I can't find any info on the motors, but they say 3,000 rpm on top.
Can I assume that 10v will spin the motor at 3,000 rpm?

Regardless, I am struggling with the gear reduction math.
The motors have a 16 tooth pulley going to a 60 tooth pulley.
the 60 tooth pulley spins a 25 tooth gear that has a dp 20 pa 20.
I come out with 1 rev = 1.047".
(3000x1.047..)/60=52.35..ips.

Would this mean i set output_scale to 52.35 in the ini file?
Should max_output be 0?
Can I set ff1 to 1?(This seems like the best reason to scale volts in this way)
And just tune p for vibration?
Or should i just stick with jt and tommy's tuning tutorials?

Thanks in advance.

 

I am building out POC with Teknic ClearPath EtherCat servos and so far the Cia402 driver is working great.. I have a question around PID tuning.

I ran around in circles trying to get the right P, I, D, FF, FF1, FF2, etc settings and couldn't get the servo anywhere near its limits before it would fail out with a joint follow error.  

I got rid of all the PID settings and now it won't fail on following but it runs a f-error of about 5.8 when I do some long mock moves (the 5.8 on the scope is a nice trapazoid shape with a ramp up, flat top and a ramp down.. )

So folks with servos that have their own internal control-loop, how do you configure your PID or tune so that when you have 3 of these guys going their combined f-errors don't cause you to make wonky parts? 

Thanks in advance..  Since this is mostly a theory question I'm not posting configs, but happy to if folks ask.