View Full Version : Checking your focus

Ross Lowry
11-07-2008, 3:03 PM
Ok I have a theory on how you can easily check to make sure your machine is focused properly, let me know what you all think.

Take a thick piece of wood and manually set your focuse and vector a straight line.
Now drop your table 1 click and move your vector line down a bit.
Vector the line again.
Keep doing this until you can tell your line is widening.
Now find the thinest line and that should be your focal point.
For example if your thinest line was at the spot you dropped the table 5 clicks, then set it manually again and drop it 5 clicks and reset your manual focus gauge.

Would you guys and gals agree with this?

Bill Jermyn
11-07-2008, 3:06 PM
I find anodized aluminum is much fussier than wood as far as focus goes. I would probably use that

Tom Cole
11-07-2008, 3:11 PM
I have done that with my machine. Also have made a guage (ruler type) to measure the distance from the lens holder to my workpiece (1.5 or 2"). On the mini, the distance from the bottom of the lens carrier is a constant because of the way the lens is mounted in the carrier. this is especially helpful if you do a lot of thick or very heavy, such as granite blocks, that the table adjustment motors can't handle (take the lens to surface measurement and add the thickness of the work and set your table to the measurement, then put your workpiece in and remeasure.

Ross Lowry
11-07-2008, 3:20 PM
I have a Epilog 45 watt mini so would that be 2"?

Rob Bosworth
11-08-2008, 10:17 AM
Ross, the easiest way to set or check your focus with your Mini is to run a piece of anodized aluminum. Send over a black filled rectangle at the suggested power and speed for your machine. Focus the machine onto a piece of anodized aluminum. Press start. While the machine is running, raise and lower the table while the machine is running. When you get the brightest spark, that should be focus. After running the test, set your focus gauge for that distance. Then you should set your autofocus to that height also. (Use your manual focus gauge, which you set in the above test, to set your autofocus height.)

Good luck.

Eric Allen
11-08-2008, 10:37 AM
I've used the vector line method in wood. I ran several lines from what should have been out of focus on the high side and then went substantially lower. I cut the lines in, then used an automotive feeler gauge to find the thinnest line, worked like a charm:)