Post by ozgeekaz on May 21, 2020 18:42:47 GMT
Here's a weird situation I'm experiencing with the MegaV XL and a JTech 7W Laser upgrade. Loss of laser intensity when traveling left...
Jtech 7W generic module on the Mega V with the following settings:
$30=100 (Maximum spindle speed, RPM)
$31=0 (Minimum spindle speed, RPM)
$32=1 (Laser-mode enable, boolean)
Using CNC.js Laser Test I can fire the laser from 1% to 100% with good control in between. Testing at 100% intensity appeared to match the 100% Constant Wave mode from the Jtech unit. All looks good, until I start moving about the head gantry.
The laser signal intensity begins to drop when traveling left (x-axis). So if I were to trace a square at 40% intensity, I get 3 even sides, and 1 much fainter side. This drop may even flicker a little. A bi-directional raster fill will also have alternating dark / light lines based on direction of travel. The loss of signal is not consistent, and appears to degrade during longer jobs.
The laser is connected without an extension cable suspending the wires away from the gantry, not using the wire tracks for the MegaV motor wires. Wanted to make sure it was not an issue with the cabling and connectors. Even a small square which produces little cable movement will have the 3 sided effect.
I understand the MegaV is running it's own version of grbl for the 4th axis. Could this be a software / timing issue? My next step is to put a multimeter on the pwm control signal wires and measure the voltage while traveling around a square. I can do this with the JTech unit unplugged just to see if the Laser signal voltage is dropping in a certain direction.
The JTech laser signal cable is wired to the MegaV directly to the Arduino Board with the + wire PWM and - wire on GND as highlighted in the (borrowed, thanks) picture below.
Jtech 7W generic module on the Mega V with the following settings:
$30=100 (Maximum spindle speed, RPM)
$31=0 (Minimum spindle speed, RPM)
$32=1 (Laser-mode enable, boolean)
Using CNC.js Laser Test I can fire the laser from 1% to 100% with good control in between. Testing at 100% intensity appeared to match the 100% Constant Wave mode from the Jtech unit. All looks good, until I start moving about the head gantry.
The laser signal intensity begins to drop when traveling left (x-axis). So if I were to trace a square at 40% intensity, I get 3 even sides, and 1 much fainter side. This drop may even flicker a little. A bi-directional raster fill will also have alternating dark / light lines based on direction of travel. The loss of signal is not consistent, and appears to degrade during longer jobs.
The laser is connected without an extension cable suspending the wires away from the gantry, not using the wire tracks for the MegaV motor wires. Wanted to make sure it was not an issue with the cabling and connectors. Even a small square which produces little cable movement will have the 3 sided effect.
I understand the MegaV is running it's own version of grbl for the 4th axis. Could this be a software / timing issue? My next step is to put a multimeter on the pwm control signal wires and measure the voltage while traveling around a square. I can do this with the JTech unit unplugged just to see if the Laser signal voltage is dropping in a certain direction.
The JTech laser signal cable is wired to the MegaV directly to the Arduino Board with the + wire PWM and - wire on GND as highlighted in the (borrowed, thanks) picture below.