K40 40W cheap laser cutter ... issues

Hi HSbne

Long time reader… thanks for the interesting info / reading

I bought one of the k40 40W Chinese LC’s ($500) as a test machine to justify a larger more expensive purchase down the track.

I have it up and running, aligned the mirrors (still needs some more tweaking) and have it working.
I can cut paper and manila folder type material ok but if i try ply, mdf or acrylic it does not seem to really want to cut very deep. I have not made it through any ply in the 3/4mm range after up to 5 passes, MDF did not seem to want to work.

running up to 70% power at say 3-5mm sec etc when testing

I have watched plenty of video and some seems to cut 4-5mm ply like butter…

i am looking for advise and what trying to understand might my issues be

any help appreciated
cheers

Have you seen this https://www.reddit.com/r/lasercutting/wiki/k40/