if have adjusted it to run 28 mA at max power.
What did you mean by this… exactly how did you make this adjustment?
the first thing is to be sure you are using a suitable material… “plywood” covers a very wide variety of trees, type of ply and so on. You need something suitable for a laser cutter. Ply from the box store isn’t necessarily a good place to start.
Next up, focal height. Are you setting the height of the work-bed correctly below the lens assembly (the moving bit where the laser comes out)? I don’t know how specifically OMTech will have set this up on your machine, but usually a little bit of acrylic on a ribbon is provided to set the right distance between your lens and your work. For the machine I think you have which would be 700mm x 500mm bed size, the lens will usually be a 2" Focal Length. That means the work must be 2inches below the bottom of the actual glass part, the lens itself. I say this so you know that I am not talking about the lens assembly/nozzle.
Thirdly, you say your alignment is good… but is it really? Its very easy to get this wrong/get in a mess with alignment. Here’s a simple test you can do for alignment (before making ANY adjustments)…
and for downward alignment (where I suspect the alignment problem will be)
If the problem proves to be a software problem, then you can illustrate the issue by showing us screenshots including settings, speeds, powers etc (taken “inside” your computer please NOT with a camera phone) and some photos of your setup and the results.
if have adjusted it to run 28 mA at max power.
What did you mean by this… exactly how did you make this adjustment?