Not sure if I am in the right category for my question, sorry if I screwed up.
Omtech 60W/50W cutting. Speed 15mm/sec, Power Max 50% Min. 50%, one pass.
I noticed today when running some test pieces that I had what I will call ghosting.
I was experimenting while cutting on the face side.
Tried a piece with the image on the down side, as I normally do. The backside had this same anomaly of bare plywood.
My first thought was maybe I have the air assist too high, 25psi, have been using that setting for a couple weeks.
Cleaned the mirrors, nothing on them. Cannot clean the lens since it is glued into lens tube. I took the nozzle off to see if there was any contaminant on the hole etc. Had a very small amount of residue at the end of nozzle and also slight buildup on the end around the hole which I cleaned off.
NOTE: I haven’t run another piece since I cleaned, supper time and I am tired.
Any possibilities are welcome. I will post tomorrow when I do another cut.
1/8" aircraft ply.
Ran a new Ramp test just before this cutting. The best cut is at 10mm. Tried several others which of course gave me too wide kerf on the surface. Kerf on backside is perfect.
Ferg, its really hard to tell what your looking at using this image.
your using a special table to support these pieces while cutting. any chance the table has an effect? could it be from variation in the plywood…although aircraft ply is fairly high quality.
I removed the dratted honeycomb several weeks ago. I have stainless steel mesh resting on the aluminum bars. I put the ply directly on the mesh and level with wire hooked over the edges that may not be flat. The wires are connected to weights hanging about three inches below the bars. I cut one complete puzzle this morning with no ghosts. The next two had the ghost.
Look close at the edges of the pieces in the photo. You can see white on the outside and inside edges which is the white photo paper. This particular photo is of the photograph side which I done to see if the ghosting was on both top and bottom. I cut with the photo on the bottom side. I tried one that I turned over with raw ply being lasered side, it had ghosts also.
I done nothing different from morning until afternoon. As I stated above I didn’t cut another piece after I cleaned the machine including mirrors and nozzle. I will do that tomorrow.
I have two pieces of the stainless steel mesh, I will place the clean mesh in the laser tomorrow although the one I used today has very little to no residue.
I second faint line is often caused by part of the laser beam hitting the side of the nozzle hole. If the nozzle is getting warm after using the laser, this is a further indication.
