More issues with new Triumph TR6040!

[Vinny Vamos]

Hi folks,

So since my first thread post on here regarding software issues with my new Triumph 50W laser (TR6040) I have now ironed out most of the issues, and in many cases found workarounds to the quirkiness of it all! The USB interface is glitchy as hell. Every second or third time I try to upload to the machine I need to pull the USB cord and plug it in again. Weird...

Anyway! The reason for this thread is related to focusing the final laser lens/nozzle on this machine. I am getting a rather wide cut on the 4mm plywood that I use the most, and on close parallel cuts 3mm apart the material just goes up in flames sometimes. This does NOT happen on an Epilog 45W that I have been using for years. I have found that "tricking" the auto-focus system and making it focus 4mm lower than it should has helped a bit with the burning issues.

So far Triumph have been rather unhelpful really. I have been put in contact with an After-Sales Manager who seems to give me tips that just do not make sense. I have asked for information on how to focus this final lens, as it's position can be moved in relation to that final mirror above it. He states that the Z axis/table can be moved up and down to focus the beam, but he is missing the point. This will not affect the relationship between the mirror and the lens! I only wish that there was a comprehensive manual for their products. Or is there an independent wiki somewhere that frustrated users have compiled so as to share the golden knowledge of lining up these machines?

There are printed graduations on the side of the tube that holds the final nozzle. The auto-focus switch is attached to this tube and when focused should apparently sit 13.5mm above material surface. Does anyone have a good method for focusing this final nozzle/lens? Maybe if I shoot the beam into a super thick piece of plexi I could then see the shape of the beam as it goes through... hmm

Another big issue I have had is that the X and Y axes are not running perpendicular (I was shocked to say the least). They then sent me a PDF relating to a totally different machine, and have not given me any proper pointers as to how to fix this other than suggesting to tighten the belts. In much frustration I went looking myself and adjusted one end of the X carriage to correct this misalignment. Loosened one collar on the central stepper motor that drives the Y axis and moved the right side down slightly. Now it is pretty close to square. Anyone with wise pointers towards this issue? I would be glad to hear from you :-).

Overall, how have other people's experiences been with small Triumph co2 lasers? When I mentioned the XY squaring issue they said that this "happens a lot in shipping"... hmm ok...

[Kev Williams]

I have a Triumph 80w 1390, about 4x larger than yours, had it 8-1/2 years now. As to your USB unplug-replug issue, I've had that problem ever since I replaced the controller about 4 years ago. Mine has to be replugged EVERY time I send a new job. I have the machine plugged into a 4-port USB hub with switches. It's just second nature now to just press the on-off switch twice before sending a new job. I suggest you get one, much easier than physically removing the plug each time! Not sure the cause, but that's the only cure I know of--

As to your focus issues- What the service guy told you about moving the table to focus the lens is correct, the distance between the last mirror and lens doesn't matter; the ONLY distance that DOES matter is the distance between the lens and what you're engraving, and that distance is critical. My machine has no auto-focus, and it has a stationary table, doesn't move up or down but CAN be removed. Because I can remove it, I can engrave all kinds of weird stuff in it. In order to be able to focus on some of what I engraved, I had Triumph make me some longer lens tubes...
lenstubes.jpg
the shortest on the right allows me to use a 2-1/2" lens, or engrave/cut thicker pieces than I could normally with a non-moving table. The next larger tube is the length that came with the machine.

The longer tubes allow me to focus on abnormal items, like the tall SS box on the left, or on the cowbells I'm cermark-lasering on the right. Note my makeshift wood table-- hey, whatever works!
ll2.jpgll1.jpg
so as you can see, the distance between the mirror and lens doesn't matter. The beam DOES need to be aligned well so that it runs straight down enough to hit the center of the lens as close as possible.

Focusing is purely dependent on the distance between the lens and the work. To focus my lenses- even on my machines WITH auto-focus, I use precisely cut stubs of whatever plastic I have handy.
In this pic my 2" red 'stub' is in use, I just drop the lens onto it then lock it in place--
lns1.jpg

--same thing here only I'm using my 2-1/2" lens and it's measuring 'stub'...
lns2.jpg

To figure out my lens's true focus point, I do a "ramp test"-- I take a 8" long or so piece of scrap material, my favorite is laserable trophy metal. I prop one end of it up with something about 3/4" above the table, the other end rests ON the table. I pre-focus the lens to what I figure is about halfway down the 'ramp'. With my Triumph I just set the power to 5% and speed to 150mm/second on the machine itself, then manually fire the laser while slewing the firing laser from one end of the ramp to the other. The trick is to get the power and speed so that it just barely engraves only a small portion of the ramp. I typically get about a 3/4" long line that engraves brightly while it fades out otherwise. THE VERY CENTER OF THAT LINE is the dead-on focus point. I'll slew the 'off' laser over until one edge of the lens housing is right above the center of the line. Then I take some posterboard or other thin cardboard and carefully trim it until it just fits between the bottom of the lens housing the engraved part, then I make a 'solid' copy of it.

I do this for ALL of my lasers and all the different lenses I have for them. While one 2" lens will be close to another, they may not have the same exact focus distance. This is particularly true with different types of lenses; I have a couple of 2" GaAs lenses whose focus distance is nearly a full 1/8" closer to the work than my ZnSe lenses...

Another thing you'll notice in my pics, I DO NOT USE CONE NOZZLES on my lens tubes! The first day I had my Triumph I found the beam was hitting the cone, so I just took it off. My other 3 C02 machines never had cone nozzles. For air assist, I just cobbled together a bent piece of copper tube and found some flex tube that fit between it and the machine's blue air feed tube. I have a couple of other air hose setups. I just use whatever's handy to make what I need to get the job done!

Anyway, I think you'll find that, if/when you do a ramp test, you'll find your ACTUAL focus point to be much different than the one your starting fires with!

hope this helps

[Bill George]

Kev you need to write a book!

[Vinny Vamos]

Thanks SO much for this very detailed reply Kev! And I must apologise for my ignorance towards the focal setup, as I was so sure that the distance between final mirror and lens mattered. I guess it doesn't. I tried your focusing trick today and now the nozzle sits about 9mm proud of the material (as opposed to the 13.5mm that the manual recommends). I will make various test cuts tomorrow and see if I can get a cleaner cut with less burning of the plywood.

with the trueness of X and Y I am very close now but need to tweak it a bit more. Any advice on tensioning of belts would be most helpful actually! Triumph have just told me to "tension the belts" but without any further guidance. Of course they should not be too tight...

[Vinny Vamos]

I have one question regarding cutting of materials on the Triumph co2 lasers. I have for years had no issues cutting 4mm birch plywood on an Epilog 45W machine, but since getting my Triumph TR6040 I have yet to succeed in cutting 4mm birch plywood. I have tried this whole week, experimenting with focus (thanks to Kev's tips), air supply intensity, and also cutting in two passes, and it seems to always burn the material to a certain degree. Sometimes the wood goes on fire, when I have parallel cuts that are close together. Again, I never had this issue with the Epilog. It seems to me that the beam has a very narrow focal range where the power is the greatest. My knowledge of this technology is limited, so do forgive my lack of correct terms. This means that with the laser focused on the top of the material I have a diverging beam as it goes through the 4mm depth, having a wider spread of energy as it goes deeper, therefore not managing the cut through and more so just burning the wood. Could this be the case? And could this be the reason why at 70% power and 4mm/s I am not cutting through this plywood in one pass? The power ratings in the provided spreadsheet are far lower than this for 4mm plywood for example. Something like 25% IIRC.

[Kev Williams]

When focusing, the prime focus distance should always be right at the material's surface, regardless of thickness. The reason is, an any point OTHER than the 0-focus distance, plus or minus, the width of the laser beam gets wider in proportion to the distance from 0-focus, and the beam's power density decreases drastically and beam width increases... Therefore, if you focus say, 2mm below the surface to better cut thru 4mm thick wood, the initial power to cut is already decreased quite a bit before any cutting takes place, and you can't get that power back... Much smarter people than me could explain it better --

below are pics of a piece of nearly 21mm (.817")thick Cherry that my 80w Triumph successfully cut thru in ONE pass--
DSC03204.jpgch1 (2).jpg
VERY slow, like 2 speed, but clear thru, with a 2" lens; so your machine should get thru 4mm with a 50w tube and 2" lens fairly easily- like your other machine--

Question: have you insured the lens is in the tube correctly? My Triumph was almost 2 weeks old before I figured out the lens was upside down, from the factory! - The conVEX side must be UP toward the last mirror, the flat side (plano-convex lens), or the conCAVE side (meniscus lens), must point down toward the work. They will work both ways but focal distance and range will be distorted...

[Vinny Vamos]

Kev, thanks again for all the further info. I checked the lens and mine is concave towards the material and convex towards the final mirror, therefore making it a meniscus lens. When you say 2" lens, what do you mean? Is it a 2" radius on the curvature (convex/concave)?

I can almost align and focus this thing with my eyes closed at this stage, yet all that Triumph keep telling me is that it is not focused. They have yet to tell me the clever method that Kev described, striking a line at lowest power on a sloped target. This works very well. I sent them the following image showing the width of the cut and the burning.
plywoodBurnTriumph01.jpg
It is clearly too wide, and of course the fact that I cannot even cut through this 4mm at full (70%/20mA) power and 4mm/s. The burnup of the centre legs of the vents only happens sometimes. When using the Epilog Laser there was a setting for laser frequency which was set low (500Hz?) for cutting wood and much higher (5000Hz?) for cutting acrylic. I can see this setting in the Factory Parameters in LaserSoft but I need to password to change it. Currently it is set to 20000Hz! If there is any correlation to the Epilog system then this is very high and would surely cause some burning when cutting wood.

Does anyone know the "authorized password" for changing the Factory Parameters? I would only be changing the frequency, as I can see there are many other settings in there that could easily break the machine.

I also tried a 15mm thick piece of clear acrylic as a known and trusted material. at 70% power and 10mm/s it got 3mm deep into the acrylic. Does this sound correct for a 50W laser?? I am not so sure...

The laser tube itself looks perfect and clean and clear. My cooling water is crystal clear still. For now I am using tap water but here in Iceland Algae grows very slowly. There is one burnt speck inside the laser tube which I have a suspicion about. Is there any possibility at all that this could be a sign of a tube that is damaged/depleted somehow? Here is a lame photo of it:
laserTubeSpeck01.jpg

If anyone has any ideas to add here then please please do. I am rather depsarate now as it has been many many weeks trying to get this machine working, and meanwhile my production of engraved panels for my products is totally stopped.

[Kev Williams]

when I refer to a 2" lens, I'm speaking to it's focus distance. A 2" lens means prime focus is approx. 2" from the lens itself to the substrate. One way to tell your lens's focus distance is to simply look thru it as a magnifying glass, at some very small print on paper, or me, I just look at the tiny date on my Fitbit watch- move it until what you're looking at comes into sharp focus, then move back and look at how far the lens is from your target. Also, the shorter the focus length, the less "play" you'll have in sharp focus. I have a 4" lens, and it's really hard to tell by eye where prime focus is, because sharp focus is pretty "loose". But even so, when I think it's close, and check, it's obviously closer to 4" than to 3" or 5"

If by chance you happen to have a 3" lens, it will be hard to cut thru wood decently with only 50 watts of power...

Are you still test engraving with the cone in place?

[Vinny Vamos]

OK understood. Well from looking at the distance between lens and material when I have this system in focus, it looks to be about 2". So are you saying that with say a 4" lens the range where the beam is at it's strongest is bigger, therefore making it more suitable for cutting thicker materials?? If so, how easy is it to get different lenses?

Yes I have been mostly testing with the cone in place. I especially need it when trying to cut the plywood as without it I cannot blow air on the cut, and the wood just goes on fire instantly, scorching the surface. I have checked the beam alignment in relation to the cone and now, after another realignment it is exiting the centre of the nozzle whether the lens tube is all the way up or all the way down. This means that the beam is coming down vertically and not hitting the edge of the cone.

[Bill George]

Turn off the auto focus, do that slope test and find the sweet spot. Then make a setting jig or whatever it takes so you can set it using the Jig you made distance to your material, not the table.

You can work with the cone in place if your final mirror and lens are aligned correctly. I have used all my machines with the cone in place. DO not change any factory settings or the lens, it will work but you can not set the focus by looking or eye use that Jig you made.

Also wondering if you ever checked the mirror alignment all the way, each mirror from the tube to the lens?

[Vinny Vamos]

Yes Bill, I have done that regarding making a jig and I have even removed the auto-focus switch as it was just getting in the way. I also removed the red laser pointer as I could not get it aligned properly and it was too bright. And yes I am using the cone, knowing that the beam is passing through it on-center.

I have now tried different settings for the laser frequency ONLY and it did not actually make any difference to the cut and the amount of burning. What has made a difference though is to focus the cone not at 10mm but at 7mm from the meterial. Maybe this is actually the ideal focus point and I messed up somehow, but at least the 10mm distance was where the center of the line was on the sloped piece (as per advice from Kev). Anyway, right now I am managing to cut through the 4mm birch ply with two passes, but it only refrains from burning with a flame if I spray the top surface with water mist before each cut (yep, I am desperate at this stage!). This efficiently prevents any nasty scorching, and even though it may take away slightly from the cutting ability/heat of the beam, it does get me an actual usable piece in the end! I have also started putting the plywood on a flat metal plate rather than the honeycomb table, and this seems to prevent burning on the underside of the wood due to a lack of air/space under there.

This leads me to my next question; has anyone tried using certain inert/suffocating gases fed in instead of the compressed air? I have been reading of bigger metal cutting lasers using oxygen and nitrogen as a cutting assist, not for suffocation but rather to actually increase the cutting ability of the beam. If I were to use CO2 for example, surely this would do better at reducing burning than normal air would?

[Bill George]

It seems your not getting the focus right per Kev's direction, I can cut 3mm birch with one pass with my inexpensive 40W Chinese machine. Just using the air supplied to the nozzle from a air pump, no burning or flare ups.