View Full Version : Newbie to Engravers - Optics Question

Joel Matteson
03-02-2012, 9:49 PM
Greetings everyone,

I've been a lifelong hobby woodworker which is what brought me to SMC a couple years ago. My wife and I have tossed the idea of a laser around for three years now, and are finally close to taking the leap! We both have day jobs which, at least for now, we are not going to quit; however, we'd like to start part time and see how things can grow. We are almost certainly going to add a laser to our complete wood shop. I've taken the advice on this forum very seriously. We laid out all our options, our finances, the pros and cons, listed our most likely uses knowing they will change, and have begun to put together a business plan. I've even purchased Corel X5 so I can get a head start on the software learning curve. I have narrowed our options down to a 40W Epilog Mini 24 or the 40W Universal VLS 3.5. Because we are new to engraving, I know we'd quickly appreciate the convenience of the customer support of these two big names. We've had our Epilog demo and are soon getting our Universal demo. I've been comparing these two machines. I know both are good quality, and I'm not going to ask which one you'd choose ...... but I am curious about your thoughts on the difference in their optics.

The Epilog Mini 24 comes standard with Epilogs 'Radiance High Resolution Optics,' which is their upgraded optics as compared to the Zing series. Universal offers, 'High Power Density Focusing Optics,' which are an upgrade, not standard. Universal claims that with their HPDFO you can engrave on metal without cermark and using as low as a 25W laser. I'm not really buying this, BUT ... I would like to know if these optics really make such a difference in the quality and capability of the machine and if having upgraded optics should be part of my plan. In line with this question ... I've gathered that the optics of Universal are much more sensitive with different air assist requirements. Can I get away with a standard air pump with the Universal, or should I add much more to my 'budget' when looking at the Universal machine?

Looking forward to a lot of interaction on this forum ... hoping to have a new machine this spring!


Rich Harman
03-02-2012, 10:02 PM
This is a good question. The Universal High density optics has an additional lens on the lens cartridge. I would like to know what exactly it does. Epilog uses a beam expander/collimator, it goes between the laser tube and the rest of the optics. I seriously doubt that you are going to be disappointed with the quality whichever way you decide.

Scott Shepherd
03-03-2012, 9:28 AM
Unless you plan on cutting very small stuff, like model railroad parts, etc., I think you'll be happy without the HPDFO. With that, you get a very small beam diameter. You also get a very small beam diameter :) Which means.....if you are engraving, it'll take more time to complete.

I have a PLS 4.60, and we added the collimator without the fine lens. We were told it would make the beam more round and more consistent across the table. I honestly, to this day, have never seen a single thing I could identify as being better with that added. I don't find the engraving quality is better and I don't find the engraving to be more consistent across the table. I'm not suggesting it's not true, I'm just saying for the type of work we do (fairly fine stuff), I personally can't see it in our application.

I'd suggest that you'll not be able to tell the difference in engraving between the two, even if one claims to be better in quality.

I don't know your application, so you might want the super small beam diameter. If you're just doing normal engraving, you won't need the super small beam size of the HDPFO set up, in my opinion.

Ernie Balch
03-03-2012, 10:40 AM
It all depends on what your main use for the laser is, engraving or cutting. Engraving does not require much power but cutting is a different story.

For cutting you can either use a very small laser spot to get the needed power density or a higher power laser.

One disadvantage of using a smaller spot size is the reduced depth of focus. As you go out of focus the power is spread over a larger area and will not cut well. If you intend to cut thick items you will be wanting to get more depth of focus and should go in the opposite direction toward larger spot size (usually a longer focal length lens) of course cutting will be limited by lower power density.

In my case I needed to engrave my logo on steel knives and cut 3mm birch plywood, corian countertop material, and 1/2" acrylic. I found that an 80W Rabbit laser will do these tasks and was under my $10k spending limit. I am quite pleased with the ability to engrave stainless steel without using Cermark.


Dan Hintz
03-03-2012, 5:10 PM
Universal claims that with their HPDFO you can engrave on metal without cermark and using as low as a 25W laser. I'm not really buying this, BUT...
It can... though what they don't tell you is it is so unbelievably slow you cannot use it from a business point of view. Speed will be <1%. So, it's possible, and for that rare project that comes along where you need a one-off, it's prefectly useable. But don't expect to compete with fiber by any stretch.

Joel Matteson
03-05-2012, 7:13 PM
Thanks everyone for your inputs ... It seems as though I wouldn't need to add this to a Universal if that's the route I take. Our demo is tomorrow night, so I'm sure there will be more questions to come!