Scanning direction of engraving using LO X7 DSP

[bluecuriosity]

Scanning direction of engraving using LO X7 DSP.

Can this be reversed so that it goes up or down the sheet depending on preference? I don't want to change top left as home position or reverse everything... just toggle the steps so they go up rather than down, or vice versa.

I can't locate any setting within the software to do this without reversing everything via datum / axis settings.

[Techgraphix]

Why should you want this???

Kees

[Telrad]

I like to engrave from the bottom up to control any discoloration of the engraving by the current pass being burnt. If you start at the top and engrave down, the gas discharge(smoke) can discolor the engraving.

[Tech_Marco]

Never heard that issue before. Can you post image to show the distortion caused by smoke?

Just curious how smoke could cause any distortion on engraving, not to mention that one should have a ventilation fan installed.

Marco

[bluecuriosity]

When deeply engraving acrylic it creates airborne particles in addition to the vapor. These particles can adhere to nearby surfaces (especially the clean face of newly engraved path) as they are hot enough to melt back into the plastic.

This is of particular difficulty in my case because I use the engrave then cut fucntion to clean up any jaggyness of the engraved hole, but a problem exists if there is additional slag present. To be clear, I am using the engrave function to "mill" a depth of about 0.5mm into acrylic sheeting.

To counter my problem I could align a jet of air to blow cut material away. But the evacuation is at the back. Because this machine scans from top to bottom I would need to direct the debris toward the front. I would be blowing debris against the natural exhaust airflow, the debris is not collected efficiently, lenses and mirrors get dirty, and some escapes the machine.

[Techgraphix]

I understand what you mean.
It's not the evacuation that matters the most, in my machine, the evacuation is done below and with a few sheets of thick plastic foil I can contain the area. When I leave a hole in front the debris still melts down on the top of the line.
I even rotated the nozzle 180 degrees and still on the top..
A few things that help is to shut down all ventilation while engraving, although you will still have some debris melted down on the surface AND you have to clean the lens (with Acetone) after each job..
Another thing that helps is to leave the protective sheet on while engraving, but you can have a hard time to get every piece off. Transfertape (from a vinyl-cutting plotter) can make it easier.
Maybe that an airflow, real strong, may cool the particles so far that they don't melt down to the surface anymore. But you risk the danger that your work-piece may blow away then.
I don't think it will be much better when you engrave from front to top. I haven't tested it yet..
You could test that to mirror the image and reverse the motor direction temporarily (manually trigger the Y-home sensor while resetting as the gantry will go in the wrong direction when you leave all settings untouched)

I even tried to cover the surface with soap, water, lampoil etc but that made it even worse..

Kees

[bluecuriosity]

Yep, I realize that there are work-arounds. I am already doing some of the things you suggest.

I just didn't know if there was a way to reverse the scan direction... it's an option in moshidraw, heh..

[Greolt]

Yep, I realize that there are work-arounds. I am already doing some of the things you suggest.

I just didn't know if there was a way to reverse the scan direction... it's an option in moshidraw, heh..

I don't think it is a completely unreasonable expectation.

Using Anywells controllers for a few years now and once or twice in particular circumstances I have wished I could reverse scan direction.

[DonL]

did you try to extend the vent of the evacuation system to the other side of the work area or use a shop vac with two hoses, one drawing the smoke off your work and the other out the windows blowing the fumes outside. You can use an upholstry attachment or something like that that hooks to the hose and is flat and wide at the end.