View Full Version : Establishing Parameters

Robin Lake
12-08-2005, 3:50 PM
In a current ongoing thread a poster wrote:

I use a 10X loupe to check things. I draw a .003 hairline on the vertical, about 1/8" in length. Engrave @ 30 pwr, 40 spd, 300 DPI and observe how the dots align and apper in uniformity.

This caused me to wonder if there were recommended test procedures to apply to a newly acquired laser. Engrave a ruler, a circle, a triangle, vector cut to a specified depth, that sort of thing Essentially, these tests would result in items which establish a baseline of performance. They could be saved and compared to the result of the same tests a year or more down the road. Would this be helpful in recovering, or reestablishing optimal performance, after the inevitable future malfunction?

I know that I would be able to make my own test products, but a newbie such as myself would not necessarily know what was most important to test (if that is the right word) for.

Thanks for reading.


Shaddy Dedmore
12-08-2005, 4:32 PM
There are a few trouble shooting things that might be applied to this. Use some scrap and vector a circle or square in the upper left, upper right, center, lower left, lower right. If you use just enough oomph to cut through, you can compare cuts across the table. (if you used excessive power, it would likely burn through just fine all over, and not be a valuable test). You could vector a large enough circle then carefully measure height and width to make sure the circle is, well, circular (or rotate the circle in the cutout, if slightly oblong, it should catch while rotating). ummmmmm. Oh, also raster in the corners and center and compare.

When doing the corners, you don't have to use a large sheet, you can use same thickness scraps in the right spots.

in the other forum, there was talk about rastering thin material (LaserLights) and how some people need to put a vertical line on the left and right of the raster image because the acceleration of the laser causes inconsistancies, but the extra lines causes the head to already be up to speed when it gets to the image. So you might raster an image, then put lines on the sides, and run it again with the exact settings then compare. If it looks exactly the same, that's good. I think it doesn't matter on stuff like wood and acrylics, but the really thin stuff like laserlights has less of a tolerance for change.

That's about all I got off the top of my head.


Joe Pelonio
12-08-2005, 5:40 PM

That sounds like a way to test the alignment I had to do when I changed my tube (while on warranty). Epilog sent me a tool that overides the door closed security feature, and I had to mount a target, manually position the head in various locations and briefly fire, then adjust the angles of the various mirrors to get consistent focus over the whole table. Your suggestion would make sure the new laser is set up correctly. I think it's also a good idea to make sure that 0,0 is in the right place in the upper left, so that when an object is in place to engrave it comes out centered to the same size and shape on your computer file. Of course it would be best if this was all done by A support person/tech installing for you, but many people are having them shipped and installing themselves.

Robin, I don't know of any actual procedure to follow for any of this. You have come up with a good idea though, that would save time when you get an actual job, by having all of the parameters for you machine for each material and thickness documented ahead of time. Later if you find those settings no longer cut through the same thickness completely you will know that something is wrong. I've found that the settings in the manual are a good place to start but I have changed all most all of them
for my machine. I was told that wattage can vary by 5-10 watts up or down for the same machine with the same wattage rating.

Bruce Volden
12-08-2005, 6:57 PM

I also wondered about this same idea~~evaluating my lasers performance. In the earliest stages of my owning a laser what I decided was I would engrave the smallest text size I could read. Back then I think if I studied it closely I could make out and read a 1 or less pica?? (now its a 12 ha ha). Anyway I put the 10 Commandments on a cherry block within a "bible" drawing. The bible measured `1.875" H X 2.125"W and I put the text within that area, 5 on the left page, 5 on the right. I made note of my speed, power, DPI and still to this day use that. My machines are getting older and more worn out now so I have to slow them down a bit to get the same results, but if nothing else proves the lens is A-OK!!!


Joe Pelonio
12-08-2005, 7:51 PM

In the earliest stages of my owning a laser what I decided was I would engrave the smallest text size I could read. Back then I think if I studied it closely I could make out and read a 1 or less pica?? (now its a 12 ha ha).

Bruce, I had to laugh at that. I have a sample on the wall to show people how high the resolution is on the laser. I took the graphics from an 18"x24" parking garage "disclaimer" sign with all the legal mumbo-jumbo and engraved it onto gold rowmark 2"x2". Even with my reading glasses on
I can't read it! It does impress people with good eyes though.

Dave Fifield
12-09-2005, 2:46 PM
If you do an alignment test and find that your laser is off, what can you do about it?

If I cut a circle with my Epilog Legend 24TT I find that it is off by more than I would like. The Y axis seems to have a little less gain than the X axis, resulting in an oval rather than a circle. There appears to be nothing in the manual about doing axis gain/linearity adjustment yourself.

Anyone know how I can increase my Y axis gain a little (or decrease the X axis gain) or is it broken and needs mending?

Dave F.

Shaddy Dedmore
12-09-2005, 3:44 PM
Might be a belt tension issue. I'd start with calling Epilog's customer support.