gouges in background of pocket file

[Rocco.G]

I've been having issues with my Z position and it turned out to be a loose connection. Having corrected that i did some tests. I have a 6' x 10' PRS aphla, ATC (though have been running it in manual mode and changing bits - long story), 5 ph spindle motor, vac table and use Aspire. Now i did a couple of test cuts with some extra HDU and while the basic cuts came out fine, i'm getting random digs/gouges in the background. I ran the file twice and am getting pretty identical patterns of the marks. I ran this with a 1/2" two edge end mill (the one that came with the starter kit) to rough out, then with a 1/8" amana bit designed for cutting HDU. Yes, a 1/16" bit should have been used because of the small lettering but I don't have one at the moment. The cut depth is 1/2" and I haven't found a 1/16" bit with enough cut depth to do that - though I haven't really searched hard. I make sure to zero the Z axis between bits. i did not use the vacuum on these, just screwed the HDU to the table bed.
I'm guessing that a high build paint might hide these, but I think they really shouldn't be there in the first place. Also, I'm getting a tiny grove around the lettering/image. I did set the tool-paths to do a final pass as well. Would that cause the groves? I mainly make electrical signs (mostly thru-cutting aluminum, acrylic and such) and don't do much of this but have been getting requests from other shops to do just this. I can't send out wholesale work that comes out like this. Hopefully these will all show well in the photos.
I did the original file in corel X6 and exported it as an EPS into Aspire. The preview on the higest resultion comes out clean with no gouges. Suggestions?20220611_092938.jpg20220611_092957.jpg20220611_093018.jpg

[evan]

Not very familiar with Corel X6, but I believe it will export other vector file formats AI, dxf, svg,... you might try one of them. Or do the entire design in Aspire. ;-)
Personally, I've had issues with the final pass setting in the distant past, so no longer use it. I believe it has something to do with the floating-point decimal calculation.
Wish I could be of more assistance

[8Ball]

They seem evenly spaced. Could it be node points? Also, I wouldn't export in eps, since I've had issues in doing so. I would export in dxf, because it saves only the vector and not the additional script of eps.

[Rocco.G]

I'll try exporting as a DXF instead of EPS. I just automatically default to EPS because that's how I've exported files for cutting sign vinyl for decades. Shopbot Support mentioned that i should ramp the plunge moves as well. I'll re-run this with the new changes and see how it comes out.

[dlcw]

That looks a little like something with the X/Y V-bearings or bearing tracks. Could be a nick in a V-bearing. The pattern seems consistent. It could also be something built up in the V-bearings. I've had this happen. Found a small chunk of material wedged deep in the V.

[signtist]

Rocco.....I had the same problem for years and just figured it was a shopbot problem. I figured it out that when you clear out the background and then the final trim pass is cutting too deep....
it's because the panel is raising up slightly from the stress of removed part. You need to screw it down better....even if you have to put a screw into the center area to hold it down better.
I found when this happens.... it's almost never along the edge where you screwed it down.....test it next problem...you can actually tap in the center and see up and down movement...just slightly...this will do it.
Hope this helps......and yes a nice thick acrylic paint does hide most of it!