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

[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.

[Dan Hintz]

There is no single source for a couple of reasons:
1) It would be a HUGE database
2) Every machine is different, so what works for one won't necessarily work for another

We can get you close on a material-by-material basis, but in the end you'll have to run some examples anyway to create oyur own database.

[George M. Perzel]

Shawn;
I recommend that you do not try to be a "plug in the numbers" laser operator. Each machine is different and even same models with same wattage lasers will give different results depending on many factors-even moreso with Chinese machines which have many parameters which can be changed.
The best thing is to try different materials at different settings of power, speed, focus, etc.-and keep of record of what works best for each. In the long run you will get to better understand your machine and how it works-and be way ahead of the game.
Best Regards,
George
Laserarts

[Rich Harman]

Power settings are not reliable because 100% on your 80W may be equal to 80% on my 80 Watt, it depends upon how the power supply is adjusted. Alignment may be spot-on on one machine and just "good enough" on another. Some machines measure speed in percent (silly in my opinion) while others actually give you a velocity (mm/sec).

Further, the spot size, and therefore energy density, varies with lens focal length - and focus distance.

[Shawn Ferry]

Thanks for the replies however I still believe such a database would be useful. Just like there are a million factors when I CNC mill or turn, tool manufacturers still give you something of a starting point from which you can fine tune. My experience may be limited with my new laser machine but I know enough about manufacturing that it would be possible to have a useful set of starting points compiled in one location. I will continue my search and in the mean time I will start my own database for my own reference. If I am able to I will post it once I have a substantial amount of information worth posting.

Thanks again.

[Dan Hintz]

Thanks for the replies however I still believe such a database would be useful.

No arguments about that... every 6-12 months, though, someone makes the same statement and rallies the troops to make up such a database (I was one of them, on other forums before coming here 7 years ago). Rabble rousing happens for a few weeks, sometimes a month or two, but in the end it always dissipates into the ether. Once you get a feel for how the machine operates and once you have that small database of materials you often work with, the energy required to continue compiling a larger database just looks too tiresome. The only people who care about such a beast are the new owners who want a quick boost into the user's seat, but once they're in the seat for a few months, they only really care about what's currently in the machine... if it's something they haven't worked with before, they'll ask, we help, and life moves along.

EDIT: My personal database consists of over 250 materials, ranging from various woods to plastics, metals, minerals, etc. I can often give people a good starting point, but that's exactly what it is and nothing more, a starting point. Once you know how one substrate reacts, you can generally make an intelligent guesstimate about how similar materials will react. Therefore, I don't hand out my database to anyone, but I'm happy to give them individual data points when they ask.

[Shawn Ferry]

Dan, I definitely hear what you are saying 100%. I've experienced it on both sides of the argument (not an argument going on here, just using the analogy) both as a beginner and an expert. That's why I didn't want to come off as someone looking to shortcut the entire learning curve, just a professional new to this particular aspect of manufacturing looking for some starting points on various materials. Your database alone, if made public, would be a tremendous starting point. There may or may not be potential for monetary gain by creating a website and posting the information but I'm sure it would help thousands of people getting into laser machines so long as they understand the information within is what YOU'VE had success with and does not necessarily mean THEY will have the same success. The information would be for reference only and mileage will vary.

As I said, if I compile enough of my own data and still feel compelled to share it I will do so at that time. Whether I get to that point or not only time will tell. The machine just landed at our shop and it isn't even set up yet.

[Bill George]

One point that maybe did not get that clear is just because a tube is rated at 80 watt does not mean it really 80 watts output. It depends on the current and the voltage plus the age of the tube. So you just can't say a 80 watt machine at 1/2 output equals whatever power. Speeds are another factor that may vary from one machine to another, and software readings may vary. I do not at this moment own a laser, but I've owned and operated several CNC machines. I am also a licensed Ham (radio) from the days of tubes and then transistors, and now IC's. So I kind of know a little about electronics and tubes. Not an expert by any means.

What I did when I had my CNC plasma cutter was make some test squares and circles and try different speeds and power settings on each cut and logged. I think that would be a way to start.
This Link if allowed may help on some of the suggested settings> http://rowmark.com/MARK/laser_guide/...tro.asp#Intro7

[Mike Troncalli]

I have to agree 100% with all of the responses. My machine is just over 2 years old. Like most here I have created my own database. My machine is one of the lower priced units and as such the tube is not the highest grade ever. But it is still going strong.. (Sorry I digress).. Anyway.... If you were to look at my notes you would see many of my entries scratched out and updated with new figures as my tube and power systems have faded a bit over the last few years... One item 2 years ago took 75% power and 50% speed to cut through.. Today it takes 100% power and about 30% speed. (This is an example only)... I guess all I am doing is to try and reinforce what everyone else has said... Don't waste your time with another persons database.. I really won't do you much good... Take the time and play and test on the materials YOU are going to use...

You offered to share your database, while I find that very honorable of you I personally wouldn't even bother taking a look at is as it would have ZERO references to anything my machine would do...

One last comment and I apologize is this comes across as curt... But you asked a question, 3 gentlemen with VAST amounts of knowledge (Dan, George and Rich) replied.. You're response pretty much just waved them off... Let me tell you... When these 3 fine gentlemen offer their help, Take it...

[Mike Null]

Shawn

Welcome to SMC. You'll find no shrinking violets here. What you're logically asking for is, in reality, just an exercise in futility.

Once you get started you'll find many volunteers to help you tackle any specific issues that confront you.

Good luck.

[Shawn Ferry]

Thanks for all of the responses guys however I did address a lot of what you are all saying in my initial as well as follow up posts. I appreciate the input but unless someone has some suggestions on speeds and power for certain materials and what their experience was with those settings it is a dead issue. I appreciate your input but as a machinist by trade I know there are ALWAYS some safe starting points from which you can make your own adjustments. You don't have to beat what I addressed myself into my head, just sayin'.

[Rodne Gold]

Hiya , Welcome
There might be a case made , if like CnC ing materials , you have all the parameters and they are the same for everyone , IE speed of feed , the same cutter , the same spindle power and so on..with lasers all these parameters differ from laser to laser.
We here would WELCOME any aids to productivity , yet you can see the idea gets at best , a lukewarm reception. That's cos we know its not a feasible idea,

[Glen Monaghan]

Epilog publishes tables in its user manual giving speed/power/frequency settings for different rastering and vectoring different materials with different tube power ratings (35W, 45W, etc.) but I found those values to never be really good on my machine, only rough starting values from which I had to do a bit of experimentation. Within a week or so, I quit even checking those values and just started with values I thought would probably be "about right" based on what I'd done to that point. A while later, I came across a table of settings from a maker site that had the same laser as I had. Its values were different from Epilog's published settings and different from what I'd found worked best on my machine. After a couple of days of messing with their settings, I gave up on them as well.

I began to keep detailed notes and even labeled samples, but soon got lazy and just went by memory. After a couple of months, though, I realized that I had experimented with so many things that I couldn't keep it all straight, and certainly couldn't remember the settings I came up with for a job months earlier and now wanted to duplicate, so I went back to keeping a notebook.

When I got a second laser, I basically had to start over because, even though it was the same manufacturer and rated power, the new machine was "hotter" than the old one. For some engraving jobs, I found it better to just lower power and keep the same speed, while most cutting jobs were done at the same power (usually 100%) with increased the speed. Although in some cases I increased both speed and power, I recall finding one engraving job that paradoxically seemed to work best by lowering both power and speed. I've again memorized the vast majority of settings that I need but still refer back to the notebook for occasional jobs and recently realized that I've had to drop cutting speeds from what they were two years ago... guess the tube is losing power.

[Shawn Ferry]

Epilog publishes tables in its user manual giving speed/power/frequency settings for different rastering and vectoring different materials with different tube power ratings (35W, 45W, etc.) but I found those values to never be really good on my machine, only rough starting values from which I had to do a bit of experimentation.

Best reply so far. Going to look into it now. Thank you so much. This fact alone that a major manufacturer posts such figures gives merit to the FACT that starting figures ARE useful. 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. So as not to let this topic turn into a "let's show the new guy how stupid he is" or a flame war or whatever, feel free to lock, delete or whatever. I got what I was looking for out of the post so much appreciated. Thank you all once again.

[Shawn Ferry]

Glen, using your keywords in a Google search I found this:

http://www.spsu.edu/architecture/fac...2013-02-22.pdf

I thought pages 44 and 45 might be useful to anyone who may come upon this thread assuming it is not deleted in the future.

Pages 196-200 of this:

http://www.epiloglaser.com/downloads...ix_4.22.10.pdf

May be useful to folks as well.

Thanks again for your very helpful post.