Laser ignites slowly?

I have a strange thing happening when I hit “play” on a job. Everything is doing what it should motion wise, but the laser comes up to strength slowly and creates a “fade in” effect. I am doing a line art image so it should be 100% strength all the time.

Here’s some pics of what I mean…

What’s really strange to me is that it’s only on the beginning and end of pass. However in the center when the laser shuts off and back on in the negative area between the images it’s crisp and sharp.

The unit I’m doing this on is my homemade CNC machine that I mounted an AENBUSLM laser (with it’s own onboard compressor) that I sourced from Amazon. I’m driving it with an SKR Pro 1.2 controller running Marlin 2.1.2.

Does anybody know why this is happening?

Looks like a failing power supply to me, because the power is irregular across the entire pattern.

It could be a poor connection along all that wiring dangling in mid-air. If there’s no strain relief holding the cable to the Z-axis head, then I’d start by looking at that poor little JST connector on the laser.

The turn-off edge will always be cleaner, because that’s just the power transistor shutting off the juice.

Also: Nice MPCNC build! :grin:

Thanks Ed!

I’ll anchor that power tighter to the carriage with velcro and let you know if if remedies it.

The damage may already be done in the connector, but if the result changes then you’ve got a good clue.

Yeah, I will crimp a new JST on to be safe.