Some time ago I bought a Shenhui laser and while the power out put is about half of what is stated mostly it cuts thin card which is what I need. It took me a long time getting the machine to an operational state, as with most people who buy these I had a lot of teething issues.
Last week a new customer wants me to cut some complicated precision gaskets (5 different parts) out of a 0.25 thick gasket paper. The cutting of the paper is not a problem, the main problem is that it doesn't cut any of the five designs accurately.
A couple of the more complicated parts have about 120 elements. eg 3mm to 20mm circles, small ovals and rectangles etc. To the naked eye it looks like it's cut spot on, but when you overlay it to a 1:1 printed drawing everything is a fraction out, but not in a consistent way - there are discrepancies all over the place. In some areas the holes are cut say 1 to 2 mm in the wrong place "north east" of where they should be, some areas they all might be in the wrong place say south west. while others are very close to where they are supposed to be.
Also the overall shape might be too big in one dimension (y) and ok in the other (x) but might be different on another part. I've tried calibrating x and y in the vendor settings but because there is no consistency with where everything is cutting incorrectly, this corrective measure is useless.
Could there be other settings in the vendor file that would affect the precision?
One other unlikely cause might be when I created the vector files. Maybe when I imported the customers design into Corel Draw could be the problem by I doubt it. The customer sent me dxf files with an isometric projection (3D representation in 2D) - when I imported into Corel there was a lot of "noise" that I had to delete, what I mean is that the part was accurate, but all the dimensions and isometric drawing got corrupted and flattened out all over the place so had to meticulously go through and select and delete everything before I saved it and imported it into the cutting software Laser works V6. I know my cutting file is accurate because I sent back to the customer to double check and they said it was spot on. I printed them out and checked myself and everything seems to be in the right spot. Maybe Corel can print it accurately but somehow it opens in Laserworks incorrectly?
If your machine normally cuts correctly then I would blame the conversion of the drawing. I use Turbocad and Cambam so not sure if I can do anything for you. Can you open the drawing in a cad program and clean it then, if not I could open for you in Turbocad and send you back a clear dxf
hi lagore thanks for your reply.
The customer has since sent me washed dxf files with nothing but the cut lines, no dimensions, layers, border etc.
Its helped a lot, I can get almost there now. so I import their dxf in CorelDraw, and then export to a format that laser works can read. I can also import the dxf directly into laserworks
I've checked outer dimensions are exactly correct in corel and laswerowks but when I cut however there is a slight skewing going on.
if I could drag say the bottom right corner 1mm diagonally down & right while pinning the top left corner as the anchor point I'd probably get pretty exact.
Its really weird and got me stumped.
If you can convert to a dxf I can use I'd be very appreciative.
not sure through this forum how to send you files?
Precision cutting issues
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