Focussing an Epilog?

[James Mooney]

I recently got a new 4" lens. Just like the 2" it has the ability to auto focus using the plunger mechanism or manually focus using the triangular measure. Obviously the manual measure is longer on the 4" (by approx 2" :)) The quandary I have is that when using auto focus, the object on the bed is set about 4 5/16 from the lens; this is 1/4" longer than on the manual measure - in fact even longer than the manual measure were to extend to should I loosen the screws and reset it! Both seem to laser ok but I assume that's due to the forgiving nature of a 4" focal length.

Sorry, that's a very long winded way of asking which is the optimal/correct distance! :o

PS. I don't even know if you can adjust the auto focus setting to correct it if needed!

[Doug Griffith]

How about using a riser block that you place on top of the surface to be lasered?

[Joe Pelonio]

Isn't there a tiny set screw on the side of the plunger that allows it to be adjusted to the exact 4"? In your case you need to push it up 1/4".

[Frank Corker]

I'm curious to know what the benefits of the 4" lens has, if someone wouldn't mind explaining it in s i m p l e terms for me

[Jack Harper]

Frank - I use a 4" from time to time. The main advantages are greater focal length, broader beam which translates into faster lasering by reducing resolution and finally smother images, especially for glass where you might see some lines appear. The trade off of course is a reduction in power but if you did not need 100% power to begin with, you just up the power to compensate. I have found this very helpful when lasering denim material where you might have seams that cause a change in focus.

[James Mooney]

I'm curious to know what the benefits of the 4" lens has, if someone wouldn't mind explaining it in s i m p l e terms for me

Frank, in your case it would be of benefit cutting 20mm acrylic. In this instance the longer focal length has a more acute angle resulting in the cut being more perpendicular (especially noticeable when cutting thicker materials) and the beam will remain in focus over a greater distance resulting in a concentrated (focussed) beam throughout the thickness (depth) of the material. The net result being a smoother/straighter cut in thicker materials.

[Peck Sidara]

James,

There's a way to adjust the auto-focus to match the manual focus. The question is...which one is set correctly?

Tech support can walk you thru checking your focus using an anodized aluminum plate. From there, you'll adjust the manual focus to match the new corrected distance.

Once complete, there is a "auto-focus" adjustment mode on the front display of your laser. Each number represents .001". We'll match the auto-focus to your new manual focus point. The owners manual also covers the "auto-focus adjust" parameter and states the higher the number, the lower your focus point will be from the lens.

303.215.9171 will get you there.

[James Mooney]

... The question is...which one is set correctly?


This is the essence of my dilemma! Thanks Peck, I'll contact tech support as you suggest.