Speeds and power for various materials for co2 lasers - specifically Shenhui 50w plus

**Travis Wizniuk** · 03-21-2014, 3:11 PM

Originally Posted by Shawn Ferry

Hello, I am new to these forums and as general forum etiquette goes I did search for what I am looking for before asking but I could not find an answer.

The information which I seek is specifically what speeds and laser power settings people use for different materials as well as what results people have experienced with those settings. I am hoping to find information specific to Shenhui co2 lasers in the 50w plus range. For instance, if someone has a 50w at 50% power or a 120w at 21% power both result in roughly 25w power. Using this example if both machines were used at 200mm/s the results should be nearly identical, outside variables being equal. I realize this is extremely general and likely to start a significant debate on many surrounding factors. I assure you it is not my intention to upset anyone and I intend to accept all answers as being within a constructive manner.

As to my question, I would like to know if there is a single resource where people have posted their results with different materials using varying speeds and power settings. I am completely new to this and I am trying to eliminate a great deal of costly "experimenting" and "trial and error" by using peoples experiences as a starting point and then varying those as necessary.

I think it would be very helpful to many people in my shoes if this information was available from one central location.

Thank you for your time.

When I started out I used this as a starting point (I have the same tube). It was fabulous as a starting point, but not one of my settings match this table now..

http://www.rabbitlaserusa.com/Manuals/SpeedsFeeds_RL.pdf

**David Somers** · 03-21-2014, 3:39 PM

Shawn,

Perhaps this will help you as well. My apologies for not posting this sooner, but I had trouble locating it.

This is a link to a forum thread where folks were discussing their preferred methods for testing materials for the correct laser settings on their machines. You should find a number of ideas in this and hopefully it will help you after you have tried the "starting points" that you were looking for.

http://www.sawmillcreek.org/showthre...ght=test+strip

For what it is worth, I am not yet a laser owner but have been digging through the forum a bunch trying to learn as much as I can before I commit to owning one. And during that time one thing I was impressed by was the HUGE variance in settings for a given material between seemingly identical machines, let along across vendors or tube types or power. I realized that the numbers the vendors provided as "starting points" for materials, while not exactly specious, were part of a big range of possibilities. Perhaps if you combine the numbers that most closely fit your machine and power and materials with the testing patterns described in that link you can come to your own desired settings without too much fuss. And do yourself a favor, once you do have some good settings dialed in for things keep track of them AND how they change over time. It can give you some good clues as to what is going on in your machine if there are problems with the effectiveness of its cutting or engraving.

Good luck! Hope this is an excellent venture for you!

Dave

**Dan Hintz** · 03-21-2014, 3:58 PM

Originally Posted by Shawn Ferry

This fact alone that a major manufacturer posts such figures gives merit to the FACT that starting figures ARE useful.

Your conclusion is faulty, unfortunately. The fact that every manufacturer includes such a list is based upon the need for new owners (such as yourself) to have some sense of where to start. You have 10 different parameters you can vary in fine increments each, so those cut sheets give new owners a warm and fuzzy feeling that they can start working right out of the box. As so many others above have said, those values are often not even close to what it actually takes. Guys like us who have been working with machiens for a while wish those cut sheets would disappear, but that's not going to happen because new owners beg for the security of knowing they exist (even if it's a false sense of security).

Originally Posted by Shawn Ferry

That and the fact that guys like Dan up above maintain a database for their own records clearly shows that these numbers are useful. If they were not and so greatly varied from day to day, maintaining a database of 250 materials would be fruitless because the lens may be dirtier one day than the next or the power supply may be out of calibration or the focus may be different or the alignment of the stars may not be in your favor or whatever. The replies are appreciated but only yours has had any information which I had not posted myself, mostly in my original post so while I appreciate everyone who has taken the time to response, yours has been very helpful and exactly the type of response I was looking for.

I think you've missed the point of what we're all saying entirely. I keep a database of those materials because my machine works well with those numbers (garnered through many many hours of testing). They will not work well on another machine. In fact, now that I have upgraded from a 60W ULS to an 80W Trotec, the database will have to be recalibrated for every material on it. The values don't vary from day to day, and if you keep your machine properly maintenanced, items like smoke-covered lenses don't happen or cause issues.

There are some similarities to this machine and CNC, but they are not identical by any stretch of the word... you've been forewarned, so ignore said sage advice at your own risk.

**Mike Troncalli** · 03-21-2014, 4:39 PM

I think unfortunately the OP has already made his mind up.. I used to be a member of a woodturners forum some years back. We had a new guy come on the forum asking all kinds of questions. At one point he told everyone how he prefered his tools to be dull so that he could "get a better feel" for the wood. Many of the seasoned and expert members tried in vain to explain to him the dangers of using dull tools not to mention the shear frustration... After about 6 months of turning he figured out how to actually sharpen his tools correctly. OMG.. Was he ever surprised at the difference it made... Eventually he became a good member of the forum.. He had to eat a bit of crow though for a little while, but he was big about it and realized if your going to ask questions maybe you should listen to the answers.... I have read many a post here from some of the more seasoned engravers and I have to admit some of them I wasn't entirely sure about myself.. But I realized these people had a whole lot more experience than I did so maybe I should keep an open mind about what they had to say... Now after 2 + years of using a laser engraver weekly (sometimes daily).. I realized that I might know less now than when I started... You will never stop learning... Granted a whole lot less materials go into the trash nowdays. Even after 2 + years I visit the forum on a daily basis just to learn...

**Dave Sheldrake** · 03-21-2014, 5:46 PM

Even between two machines fitted with everything the same there is a HUGE variance between them and their ability. Like Dan I keep a set of figures for the machines I have and between two machines purchased at the same time with same batch tubes they still vary enough to stop one machines figures working on the other.

cheers

Dave

**Shawn Ferry** · 03-21-2014, 8:59 PM