Help for interval in scanning mode

[Jean-Christophe]

Hi,

i ordered a Ruida RDC6445G controler for update my chinesse laser.
i add 2 stepper motor (X & Y) because the motors were directly connected to the old controler, and i set the ruida controler without problem. I have no precision problem (thanks to this forum and to Russ videos). i can cut a 10cm squarre with less 0.1mm precision, but in scanning mode i have a problem i can't solve. i'm looking for it since a week, and i don't understand what's wrong.
The engravings do no bother each other : when the head goes from left to right, the engraving start 1.5mm before the expected starting. When the head goes from right to left, this is the same thing. This problem appears when the speed is 500mm/s. If i reduce the speed, the lag is smaller. If the speed is 50mm/s or minus, the problem is not visible.
the laser lights up approximatly 3ms early (time needed for 1.5mm at 500mm/s), or the X motor is late.
I tried to change parameters for my stepper motors (400 steps/rev or 1600 steps/rev) but the problem is still here :

scan mode.jpg

scan mode at 500mm/s (power 8%)

i obtain two circles in scanning mode instead of the blue one.
Have you any ideas what's wrong ? Can i change an parameters on controler ? (my old controler was perfectly able to scan at 500mm/s)

scan mode2.jpg

The shift is reduced when the speed is slower

Sorry for my bad english, this is not my native langage.

[Pete Cyr]

Your English is much better than my French.

1. I believe anything greater than 400mm/sec is too fast.
2. Go to the webpage linked below...perform the checks and see if that resolves the issue

https://cartonus.com/how-to-improve-eng ... r-machine/

[Jeffrey Aley]

Try going to the menu at Config -> Setting.
Tick the box labeled "Scanning (Reverse Interval)".
Add the reverse interval and Offset for the speed you are using (500mm/s).

Notice that the Reverse Interval is in the units of DISTANCE, so you will have to calculate the correct interval based on the TIME and SPEED that you have observed.

In your case, if it is true that the laser fires too EARLY, you may need to enter a negative number for the Reverse Interval.

[Jean-Christophe]

Hi Pete and Jeffrey !

Tanks a lot for your help ! That was the solution for my problem.

before-after.jpg

So i added this parameters to test :
Speed (mm/s): 500 | Reverse Interval (mm): 1.5
It's fine, i will add intermediate values for more precision.

this is what i can see on my controler after i added this parameters :

controler.jpg

Thanks again !!