Back of material marring during cuts Helix 40

[Makrel Johnson]

I have an Epilog Helix 40w that when using the vector grid and cutting, I get burnt hexagons from the grid on the part. It looks like it might be vaporizing something in the grid but I'm not sure. This just started recently and I'm not sure if it means I need to clean out my grid better or the settings are off. Is this flashback?

I did just clean the grid last week with Super Clean and an older synthetic brush but I think need to get some big, fuzzy pipe cleaners to scrub out the honeycomb so it doesn't take 2 hours to clean.

I tested on a tongue depressor, but I'm getting that mark as well on laser-able finished Alder and it's marring the finish in the exact same shape...

Example:
Depressor Markings.jpg

P.S. HI! First original post - digging the cumulative knowledge here!

-Mak

[Glen Monaghan]

Did you by chance mash some of the edges of the honeycomb over, causing more reflections/scorching off the hexagon sides at those locations? Did you wash away all the gunk and cleaner, or is some of that still there, vaporizing onto the back of your substrate?

[David Somers]

Makrel,

It looks like your tongue depressors are placed where the parts are being cut? Can you place them in between the parts so the depressors themselves are not being cut?

Can you clean the soot off but rubbing the part with a cloth soaked in DNA? (Denatured Alcohol?)

Regarding cleaning your honeycomb. I have been using LA;s Totally Awesome cleaner/degreaser that I picked up at a Dollar General Store following someone's suggestion. Gawd help me....it is "as seen on TV!!!!" but it also seems to work well. I spray it onto my honeycomb, let it sit a bit, and then hose it off with a forceful hose or a power washer at a distance so I dont hurt the honeycomb with the force of the spray. My honeycomb is steel and it has not caused problems with the metal, or with the aluminum frame. If I need to be more aggressive inside a honeycomb I use a bottle brush that is just a bit larger than the honeycomb. I also do not let my comb get that dirty before cleaning it. The process goes faster and easier than if I let it get really scrungy.

Hope that helps.

[Michael Hunter]

Could be that you have the power set too high.

I would reduce the power until it just cuts through cleanly. For wood or ply, I would then bump the power up again by about 10% to make sure it **always** cuts through cleanly (as wood is rather variable). With lower power, the flashback should be much reduced.

For critical stuff, I put transfer paper on the back as well - the marks peel off afterwards with the transfer paper.

[Mike Null]

I believe Michael has nailed it.

[pete hagan]

Michael is spot on. Use transfer tape and if you can make yourself a bed of nails for the item to sit on. Really solves the flashback issue.

[Keith Winter]

Its a dirty honeycomb + flashback

[Makrel Johnson]

Thanks for the replies - I took it out and had a good look and I think it's most of the above: still a little dirty (but no bent fins) and maybe some cleaner left, though I rinsed pretty thoroughly.

I'm going to give it another cleaning and back off the power like Mr.Hunter says. I think I'll also raise the piece off the grid too with backing paper JUST to be sure.

@David Somers - The depressors were what I was test cutting to see what was happening and the gunk was what was left on the back. I cut the alder before the depressor by itself. This is why I was worried.

I'll give it a go and report back... Thanks!

-Mak

[john passek]

Michael is on the mark, I was getting the same thing so I dialed the power back and don't have issues anymore.