Speedy 400 Laser Firing Problem

[Chase Williams]

Sorry please let me rephrase, it will not work below 50% power but 50% and above it will fire. The tube was just fully tested a second time at Evergreen, so i feel pretty confident that its in good shape. Im 99% confident that the issue is in 1 of 3 places, the motherboard, the cable, or something with the tickle power. I just dont want to use good money to chase after bad and would love to isolate the problem. I am leaning on the motherboard as thats where the PWM, I would think would occur and think that might be the issue as the previously tested RJ45 PIN 1 was showing proper voltage. Im hoping for it to be the cable.

[Chase Williams]

Trotec today sent:

Hi Chase,

This seems like a bad tube to me. Especially after reading that you tested each power supply while isolated and the 5volt signal on the board.
Thats really all there is left to do.

Evergreen doesnt have a trotec laser. All they do is hook up a single power supply to it and usually just test for 100% power that its firing what its supposed to.
Generally evergreen only refills the gas, they do not test or replace the boards, sensors, etc that are inside. There is an rf board inside I believe that gets the signal from the I/O board so it knows how much power to send. Its not just a refill the gas and thats that.

Even if we send a tech on site which is pretty much where we are at, we would need one of our tubes there to swap out and see what happens. because all we do is test power supplies, test for 5volt signal, then ask for a tube.

END EMAIL

I don’t know what to think but will agree that nothing seems wrong with anything but the tube, if you rule out that it’s impossible for the tube to be defective than the signal cable or motherboard are the only options but there is no sign of error from either. At this point I’m inclined to agree with Trotec on this one and feel like I am looking for unicorns on a laser that has very little wear and shows no signs of problems short of tube. If anyone can help me understand who is right and why it would be great! I have an extremely hard time believing the motherboard has failed, I think its possible that the multiple cables to RJ45 has, but again think that its a stretch compared to the tube as there is 900hours on the machine and it never moved until extremely recently only to move locations. I put aside the laser as Evergreen tested it, but to be fair I do not know how they tested it or anything else. It is very possible that it will work 100% of the time at 100% power, as Trotec mentions was the testing method. I thought I remembered Evergreen saying that they tested at each 10% interval for an hour, but not sure, even if they did, is that for/during the refill process, or is the completed after the fact (if it does happen)? In any case the simplest and most logical answer is bad tube, but if the tube is truly tested then it has to be cable or motherboard. I was told tickle power shouldn't change between recharges/tubes.

[Ronald Blue]

I have no knowledge to help with but some thoughts to add. Trotec sees Evergreen as a competitor so they are naturally going to blame them. They did after all potentially take a sale from them. In fact I don't know if I would have even brought them up. I've encountered similar situations and that just gives them an out. I would reach out to Evergreen and ask them on how they test the rebuilt tube. I'm surprised it wouldn't be accompanied by a test document showing it's performance at each setting. Like I said I know less than a fence post about lasers but have experience on other things

[Chase Williams]

When i sent the ticket to Trotec I put a link to this post here, which I think is fair to illustrate that I've done a fair bit of diagnostics and that I'm capable vs being discounted on what would be presumed my lack of ability. I dont know if Trotec blaming Evergreen is unreasonable here, I did a search to see if anyone else has used an oscilloscope to check their laser and cant find anything. This paired with two different Trotec techs not mentioning it seems to me that an error along these lines is pretty uncommon. I am going to take an o-scope to the laser tomorrow, if my mind is thinking right that should solve this debate. If the o-scope shows proper function, then its the tube, plain and simple nothing else could be wrong. If it's the tube, I am going to be frustrated at all of the lost time. If somehow the answer is not clear tomorrow, my Trotec rep said he would be stopping by in the next two weeks. I wonder if he could bring an exchange and if that solves the problems, naturally I'd have to pay for the exchange, but probably wouldn't if it didn't work. I just feel like all along the tube has been the natural answer to this problem and that I have been chasing unicorns in the machine. I just simply trusted that if Evergreen said the tube was good, especially with two tests, it was good... but I dont know how they are testing and if its "good" only at 100% power or everything in-between. I'll post more when I know more.

[Kev Williams]

Where's Dave Sheldrake when you need him? -I'm sure most of us know Dave is/was THEE authority on lasers around here, but unfortunately, his time on the creek has been sporadic as of late.
This here >>> https://sawmillcreek.org/showthread....t=#post3063798 --is a link to a thread where Evergreen is discussed; it's scrolled down to post #6, read Dave's thoughts about about Evergreen...

And I must add-- while I have no grudge against Trotec, and have personally spoken with one of their reps who was in town awhile back who was very courteous and professional, the tone of that letter above reeks of sour grapes. And to flatly state Evergreen "Generally... only refills the gas, they do not test or replace the boards", well, I personally know that's not true. From an email from Jean during my tube repairs 2 years ago:

Hi Kevin,

The tube was filled yesterday, but at least half of your rf electronics are not working. Our head tech (my husband) has been in the hospital since Friday. He handles all rf repairs. He is expected back to work next week. I will update you then. Have a great weekend!

And I also spoke to Jean on the phone later on, whereas she explained in great detail to me that, after my 40w tube would only muster 31 watts after a recharge and RF board rebuild, that it was likely due to bad mirrors within the tube, that it would be around $1600 to replace the mirrors, but advised against it because they'd at-the-time been dealing with warranty issues with their mirror-vendor's replacement mirrors failing or not performing correctly, and they hadn't found suitable replacements....

--I may be prejudiced a bit, but that doesn't sound like a 'just does re-gassing' shop to me... And IMO, ANY thing Sheldrake has to say about lasers or others who knows about them is GOLD. However, to be sure, I can't speak to Evergreen's expertise with Trotec lasers, but in my mind the difference between a "Trotec" laser and a Synrad laser to Evergreen would be akin to the difference between a Holley and an Edlebrock carburetor to a seasoned mechanic: The do the same thing, just made a bit different...

I'm afraid I'm about out of ideas, so best I got is, good luck from here! thumbsup.gif

[Glen Monaghan]

I am going to take an o-scope to the laser tomorrow, if my mind is thinking right that should solve this debate. If the o-scope shows proper function, then its the tube, plain and simple nothing else could be wrong.

The vast majority of portable meters used to check voltage (volt meters or volt-ohm-milliameters/VOMs) are battery operated and can safely read the voltage difference between two points in an electrical circuit.

In contrast, virtually all garden-variety oscilloscopes are plugged into the wall and have their negative probe referenced to ground. In general, you connect the negative scope probe to a circuit ground and then probe different circuit points with the positive probe. So far, so good.

However, it is VERY common for power circuit outputs to be floating or referenced to something other than ground. For example, with a 40VDC supply, we generally assume the "-" output is ground or 0V and the "+" output is 40 volts higher than that. If true, you can connect your scope across the outputs and see any voltage fluctuations. The problem is that some supplies fix the "+" output at some particular voltage (and that voltage could be floating without any direct reference to ground) and then regulate the "-" output to be 40 volts LOWER than the "+"). If you connect your ground-referenced scope probe to such a supply's "-" output, you are going to short circuit the power supply output stage through the probe. Depending on their circuitry, you likely will blow your scope's input amp and possibly fry the power supply output regulator. Even if you don't damage either, you won't get an accurate reading.

Moral of the story: you need to use a floating differential input scope (uncommon and expensive) or an isolated battery powered scope, or you need to know in advance that the signal points you are trying to measure are ground referenced. Otherwise you won't get a proper reading and are likely to fry some circuitry.

[Chase Williams]

I appreciate the advice and will share it with the engineer thats testing it. Below is what Evergreens expert has said, I am assuming I run little to no risk with using the ground as the proper pins. The o-scope and PWM, is out of my wheelhouse and I have an engineer friend coming to assist. I will make specific note of your comments to try to keep from causing bigger problems, if there is any fear or hesitation from my engineer friend than I will see if the Trotec rep might be kind enough to bring an exchange in a couple weeks and see if that does the trick.

START
First, there are three things the laser needs to fire. It needs the correct DC voltage, I believe in this case, 40.3V. It also needs the "Enable" signal. This is typically connected to the interlock circuit on the machine. The actual circuit on the laser is Pin 3 being grounded to either pin 7 or 8. Third, it needs a PWM signal to tell it to fire, and at what power level to fire at.

So, that said, you could actually fire the laser by powering it with 40.3 volts, taking a RJ45 cable, tying pins 3 and 8 together, and sending a 0-5 volt PWM signal to it, pin 1 being DC+ and pin 6 as the return. The 0-5 relates to 0-100% power.


One thing that is raising a flag here is that you said you checked all the optics. Where are you determining that the laser is not firing? Have you actually checked the beam directly from the tube, or are you looking after the lens on the work surface?


It is possible the laser is firing, but the beam is out of alignment, and not hitting the lens.

END


I have checked all of the optics and everything is perfect and aligned, I can at least test ensure that part is right with the laser on 100% power.

[Kev Williams]

Question: How does Trotec drive the red light? I ask because, IF Trotec does this similar to my LS-900 (and my BIL's LS-800), then I have another suggestion...

Here's how mine works, best I can draw up in Corel, I'll try to explain

there's a "block" connected to the front of the laser,
in the block is a mirror that swivels 45°, swiveling is done via a
plunger type relay, that via an arm somewhere, will move
the mirror. This 'block' also contains a switch that de-activates the
laser if the LED is on. Hopefully my drawings help explain...

First is LED-ON main beam OFF... here the mirror is blocking the
main beam, which should be off via the relay switch, and the
red LED is on, using the mirror to aim it to all the other
main mirrors...
beam off.jpg

This shows LED-OFF and main beam ON, the relay has moved the
mirror out of the way, LED is OFF via the relay switch, and the
main beam is now ON, hitting the mirrors as normal...
beam on.jpg

WHAT I HAD HAPPEN many years ago and just remembered, is that one day the relay wasn't 'clacking' like it normally does, and the laser wouldn't fire... After digging into the block, I found that the mirror had come un-glued from it's plate! Took awhile to figure that out, and not much room to work but I was able to superglue the mirror back in place without having to remove the block, and it's been fine ever since!

So I'm wondering if Trotec does this a similar way? My GCC's setup (Basically same Synrad tube, only 35w v 40w) is the LED is mounted in a way where the LED hits a separate 1st mirror from the main beam's first mirror, allowing both beams to use the mirrors at the same time, which actually pretty cool.

so my questions NOW are, does your machine have a mirror that could block the main beam if something weird would happen? My relay is basically another interlock, like the door interlock switches, wondering if yours has another interlock separate from the door switch interlocks?

I realize most of these issues wouldn't result in a 50% fire, but a goofy mirror could possibly be to blame?

[Chase Williams]

Thought I would give a quick update, Sorry for the dramatic delay, things have been very busy. I finally got a minute to mess with the speedy 400 again (We still haven’t gotten it functional yet). I am sad to report that after realigning everything and getting it calibrated that there are still problems. I am a 80/20 between saying it is a bug in the software (or more likely the INI file) and it being a bad tube. Here is my case for bad software: The laser functions as it should with certain settings (100p 20s, and some others), then when it comes to 100p 40s it will not fire, its hard to understand why the speed settings would effect the laser firing, if anything I could understand power settings potentially causing an issue via pulse width modulation but that should be unaffected in speed settings. Additionally, it’s not as if the laser is just dying, it works exactly as it should on certain settings both before and after it malfunctions with other settings. Attached is a video that shows the problem. Let me know your thoughts and if you have and ideas and/or agree that there might be a bug in the software or INI file.

Video: https://sharpmediallc.com/trotec.MOV
INI File: https://sharpmediallc.com/INI

[Mike Null]

I don't think you can compare the Trotec ceramic tube to
coherent or Synrad as they are a different technology. I am inclined to agree with Trotec. The only time I had to have a tube rebuilt it was a
coherent and I sent it to Photovac in Ohio. It was expensive but came back better than new. Photovac will not accept Iradian tubes for rebuilding. I don't know all the reasons but there seems to be some difference in the process and they felt they could not warrant their work.

Evergreen has had good recommendations so I'm not suggesting they are less than competent.

[Chase Williams]

I spent about an hour and a half on the phone yesterday and another hour fifteen today with a tech that I have worked with previously and know is competent. We did a lot of testing and did not find a 100% conclusive answer however, we have moreorless ruled out the motherboard, as the proper voltage signals are coming through on it. We assessed the tickle power as that excites the laser prior to firing, yada yada yada. Where we landed is that it is isolated to either a power supply or the tube... and much more likely the tube. I got a good education on tube recharging/exchanges (at least iRadion tubes). So apparently Trotec owns a portion of iRadion, which makes sense, and when an iRadion tube gets recharged they actually go into electronics of the laser tube and program stuff in at each recharge. iRadion is the only company that can program the laser tube electronics upon recharge and nobody else can. The tech was unclear if that modification upon recharging really makes a difference in the function or not plus he was unsure of the full scope of what they program in upon recharge but he was confident that they program stuff into the tube. So that is interesting. Additionally he mentioned that one of the major laser tube recharge company's mentioned many times on this forum used to recharge for Universal (Trotec bought Universal) and that they used a bench test to test tubes and that when they were installed in machines they got a significantly different result, to the point to where Trotec/Universal sent out a Universal machine to this recharging company and they struggled to recharge tubes above 50-60w on the machines (not bench). I can also say that the same company as I have talked to them, said they recharged for Trotec and while its technically true, they only recharged for Universal machines and not Trotec machines, yet passed it off as if they were contracted by Trotec for Trotecs (I find this to be deceptive practices). I am questioning the following as my tube, while recharged by a different company than what Trotec contracted in the previous sentence 1.) As previously noted there has been issue between what happens at the bench and what happens in a machine and I am pretty confident mine was tested at the bench and I dont think another Speedy 400 machine was present to test on. 2.) Nobody but iRadion could reprogram the electronics at the tube for the recharge. This may explain why there seems to be a lot of failure in recharging iRadions amongst 3rd parties.

Short of learning about the programming of the laser electronics upon recharge today, I am pretty confident that co2 lasers haven't really had any improvements to the firing mechanism in decades. The improvements are elsewhere such as the tube material (metal, ceramic), I'm sure there have been changes in the gas mixture, but the firing mechanism to my knowledge hasn't changed and is consistent amongst all co2 lasers I've been exposed to. To my understanding lasers use tickle power to keep the tube excited and electrical current to make the laser fire, pulse width modulation is how the turn the laser on and off so quick. I am not sure on the newest lasers if they use a digital signal vs pulse width modulation (which essentially makes an analog signal extremely fast), but I believe the iRadion 156f, which is what I have is still in the most current machines. The Synrad we have does this though an RF line and its own power supply the iRadion does it though a complicated RJ-45 connection with power supplies Trotec choose, but its the same process just via different connectors. I think its fair to compare Synrad and Coherent with iRadion, unless there is critical programming that needs to be done by iRadion at time of recharge.

As for final diagnosis of my machine, all roads lead to the laser tube or significantly less likely a power supply. I have already put a multimeter on the power supplies and everything was perfect, however I did it at idle and it was mentioned to try it under load, that should happen tonight*. Additionally, we turned the test pulse up to 100% as it was not firing on the settings that I had previously had working and again no fire, but I could hear fans varying RPMs in a struggling manor. The tech explained that is usually an indication of a bad tube and that something is causing it to be more power hungry, which would make Kev's Post 15 fit or even if that wasn't it again point to the tube.


I think the multimeter test of the power supplies under load is probably a bit of a reach but its a lot cheaper fix then a $3200 tube exchange, if there are findings. I suspect that the tube is the culprit of these issues. I will test the power supplies and write back. Assuming the power supplies are normal, I expect to be spending $3200 tomorrow.

[Bill George]

I would have thought testing the power supply under load would have been one of the first things to do. Since there is more to recharging the tube than just a re-gas but complete Proprietary control electronics inside to be checked and adjusted, I would have trusted Trotec to give you the right answer.

[Mike Null]

Chase
I believe Trotec purchased 2 or more Universal distributors but not Universal company. Certainly, I could be wrong, but the ULS history page makes no reference to it. My Trotec rep is one who came aboard as a result of the Trotec purchase of the Texas ULS distributor.

[Chase Williams]

So I got the new tube from Trotec today and laser problem solved. The tube from evergreen was lucky to burn masking tape (what I use to calibrate the mirrors) at 15% test pulse, the new one doesn’t struggle at all at 5%. Even when trying to hit a mug on the rotary that our 60w can do at 100p 20s (cleanly), with the same setting on the Evergreen tube it couldn’t vaporize the powder coat, just melt it. It seems that the tube just wasn’t recharged right. Various power setting including 100p and 50s worked without flaw. I’m very happy it’s functioning finally.

I am not sure if there was a fluke on evergreen or what but I’ll be reaching out to get my money back, as I wasted a lot of time and money on something they “checked” and I resent to be “checked” again. Hopefully they are honorable about the situation, I’ll post with the results.