Crazy Machine

[Steve Krahn]

So I am having this problem with my CO2 laser. I have two machines which are both chinese based. Same wattage tube and everything. The one is showing up like it is supposed to when engraving at 350 mm/s, 24% power, and 350dpi.

457220

The other one is showing up like this:

457221

That was the same exact file, from the same computer, and the same program in both runs. So far, I have checked cleanliness, alignment and I have replaced the controller, PSU, and moved the tube from the other machine into this one, all leaving me with the same results. Does anyone have any idea what I could try to get this working again?

[Bert Kemp]

the only thing I can think of is the wood is different somehow.

[Steve Krahn]

Bert, I don't think that is the problem. I have tried on baltic birch, solid poplar, and solid spruce. All with the same results. Here is a picture with both machines on the same piece of wood. The top is the machine in question:
457243

I can't explain it well, but this chart kind of shows what is happening. The power seems to ramp, and not stop where it is supposed to stop:
457244

[Bill George]

I would contact the people you purchased the machine from. I hope it was Ray Scott at Rabbit USA he is the owner and gives wonderful support to his customers!

[Bert Kemp]

I agree get in touch with Ray or Carol , even if you didn't buy from him he can proabaly help. They are awesome when it comes to helping.

[Steve Krahn]

I bought my Rabbit from him, but I bought my second one closer to home. I have experienced first hand that Ray and Carole are excellent to deal with, and the guy I bought this one from is as well, but it seems to be a problem that people haven't seen before. I am sure we will get it figured out.

[Bert Kemp]

please keep us updated especially if you find the solution . I have a Rabbit too.
I bought my Rabbit from him, but I bought my second one closer to home. I have experienced first hand that Ray and Carole are excellent to deal with, and the guy I bought this one from is as well, but it seems to be a problem that people haven't seen before. I am sure we will get it figured out.

[Glen Monaghan]

I'm guessing this is an example of how longer stretches and shorter stretches of engraving can differ due to speed/power profiles. It often is first noticed when engraving text that has ascenders or descenders (such as the bottoms of "g", "j", "y") and the ascenders/descenders don't engrave the same as the main body of text. The laser head has to sweep across the full width of the main body of the text, but the software may try to decrease job time by making shorter sweeps across just the portions of letters that extend above or below the main body. Example: "This is some text having a sole descender in the middle." That one "g" in the middle is the only place where part of the text drops below the main body so, after engraving the main body of text, the laser can either plod along sweeping the full width of the text even though it only fires briefly at the descender, or it can finish the engraving much quicker by making very short sweeps to raster just that descender. Those short sweeps frequently won't engrave the same as longer sweeps due to different ramping speed and power profiles.

In your example, I'm guessing that the head on the "good" machine is rastering the full width of the design all the way from top to bottom, giving the entire engraved area a uniform look. In contrast, the head on the "bad" machine is likely rastering across the entire upper and bottom bars, but skips the blank area and only rasters across the narrower middle section. Watch each in action and see if this is true and, if so, compare settings to see what is different. You may have settings to tweak the speed or power for that situation, or you may have a setting that prioritizes speed vs quality for raster jobs. Prioritizing quality causes the laser to raster across the entire artwork bounding box on each scan, while prioritizing speed causes the laser to skip/ignore any blank space on the left and right sides of each scan and raster only from the first non-blank pixel to the last non-blank pixel. FWIW, while installing a Trotec last week, I noticed that they have a raster quality setting for exactly that purpose.

[Kev Williams]

I've experienced similar issues with my Triumph, mostly when trying to run Cermark too fast. I can't find my pics but this is kinda what happens:
457349
the upper version would happen at higher power, the long expanses would over-cook the Cermark to gray,
while the short expanses would be nice & black...

The lower version is what happened when attempting to lower the power to compensate;
the long expances would now be nice & black, but the short expanses would wash off because
not enough power was applied to fuse the Cermark properly... very frustrating!

However, Cermarking stainless is the only time I've noticed this issue, engraving plastics and wood isn't a problem. It DOES do it, but it's only noticeable if you look for it.

I believe this can be corrected, at least somewhat, in the controller's settings. But what settings to change, I have no clue!
Here's some of my Triumph's Lasersoft/PhCad parameters:
457350
I would love to find an explanation as to what all those parameters mean! I HAVE made some changes that's resulted in WAY less laser head overrun and much cleaner curves when vectoring, but I couldn't tell you which ones! ;) But I'm thinking some of these numbers may temper down the difference between the power applied over short v long expanses...

[Steve Krahn]

Glen, I added a border around the engraving to make sure that it was going the same distance for the whole engraving, and that does not fix the problem. So I don't think that this is the issue.

[Steve Krahn]

I've experienced similar issues with my Triumph, mostly when trying to run Cermark too fast. I can't find my pics but this is kinda what happens:
457349
the upper version would happen at higher power, the long expanses would over-cook the Cermark to gray,
while the short expanses would be nice & black...

The lower version is what happened when attempting to lower the power to compensate;
the long expances would now be nice & black, but the short expanses would wash off because
not enough power was applied to fuse the Cermark properly... very frustrating!

However, Cermarking stainless is the only time I've noticed this issue, engraving plastics and wood isn't a problem. It DOES do it, but it's only noticeable if you look for it.

I believe this can be corrected, at least somewhat, in the controller's settings. But what settings to change, I have no clue!
Here's some of my Triumph's Lasersoft/PhCad parameters:
457350
I would love to find an explanation as to what all those parameters mean! I HAVE made some changes that's resulted in WAY less laser head overrun and much cleaner curves when vectoring, but I couldn't tell you which ones! ;) But I'm thinking some of these numbers may temper down the difference between the power applied over short v long expanses...

Hello Kev, I have played with just about every setting available. I have matched settings with other lasers that do the engraving with the exact same file perfectly. Thank you for the input!

[Glen Monaghan]

Beats me then...

[Steve Krahn]

Ok, so here is an update picture. Still haven't figured out the problem, but perhaps this can give some more clues.
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I exported that file to the laser at 350 sp, 20% power, and 300dpi. I slowly started increasing the power by .5% at a time. You can see that when I got to 22.5%, it jumped. This is engraving from the top down. After reaching 24% which is where I noticed the problem in the first place, I started going back down by .5% increments, and it jumped back up at 21.5%. I am so clued out as to what is going on here. We thought that maybe it was perhaps the software, but we have tried multiple computers, I have uninstalled and reinstalled, but to no avail. The controller, power supply, and tube have all been replaced. All which worked flawlessly in the previous machine.

[Bill George]

Have you checked your mirrors to see if you have a loose one? Out of alignment? Lens, I had one I swore was tight but lo and behold the magic fairy must of loosened it in the holder, because I KNOW I had it tight.

[Steve Krahn]

Have you checked your mirrors to see if you have a loose one? Out of alignment? Lens, I had one I swore was tight but lo and behold the magic fairy must of loosened it in the holder, because I KNOW I had it tight.

Unfortunately that was not the issue.

[Bill George]

Unfortunately that was not the issue.

So what was the issue? I am guessing you have checked all this first, along with the connections.

[John Lifer]

No two chinese lasers are the same. Even if they are supposedly identical. But are the tubes from same manufacturer? It looks to me like the power is way higher on the second machine than the first. And that could be from actually different tubes, or even as simple as the power supplies putting out more/less power at a set percent. None of these have the same ramp also. 20% for one is 25% for the other. But we would like to know if you resolved it.

[Steve Krahn]

No two chinese lasers are the same. Even if they are supposedly identical. But are the tubes from same manufacturer? It looks to me like the power is way higher on the second machine than the first. And that could be from actually different tubes, or even as simple as the power supplies putting out more/less power at a set percent. None of these have the same ramp also. 20% for one is 25% for the other. But we would like to know if you resolved it.

Still trying to figure it out. I have tried nearly everything, and to no avail. Yesterday I was able to do some pretty nice engravings when I only engraved files with one object. BMP didn't work or a vector with more than one object. Today that isn't working either. Nothing consistent is happening, so it is very hard to test. We will be testing a new controller tomorrow with a new computer to see if there is somehow a bug in the software. I had thought originally that it was a hardware issue, but there are no consistencies. One day it works to do this, but not that, the next day nothing works. Then just part of the file will engrave properly, and then not. It really is making very little sense. I have already tried a new controller, power supply, and tube. I've gone through the wiring that I can, and everything seems to be connected properly with no worn out wires. This machine has 60 working hours on it, so it hasn't seen a lot of use. I really am at a loss here.

[Steve Krahn]

So at this point, we have tried just about all we can. Nothing seems to be working. None of the tests are showing consistent results of any sort, so the supplier is going to be trading my machine with a new one while they try to get this one going so that I can get back up and running again. I will do my best to keep you updated when I get updates on the situation. Thank you guys for all the suggestions and your time!

[Steve Krahn]

After two weeks of struggling, it was the USB cable... I had tried a different one in between, but that one apparently didn't work either, so I didn't think it was a fix. I am now up and running again though!

[Bert Kemp]

After two weeks of struggling, it was the USB cable... I had tried a different one in between, but that one apparently didn't work either, so I didn't think it was a fix. I am now up and running again though!
Awesome thanks for letting us know:D