With the planned relocation of laser and total re-work of the exhaust system, this is simple to plan for.
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Absolutely, and that would help. What we couldnāt do it create a better designed exhaust plenum to take full advantage of larger blowers. Iām not sure what the plans are for the expansion but it might be too late to change them, especially without proof that it would be an improvement (I.e flow inside the laser isnāt the bottleneck).
Yes and no on this. In my experience at some point the fan can overcome poor plenum design, especially in semi closed environment like the lasers. Most of the lasers have less than 10 sq feet of air to cycle. By insuring or if necessary creating proper airflow with vents you can overcome this without trouble. It doesnāt have to be over engineered either. Though you know we will 
Better exhaust fans, thatās what Iād say. Ie an actual exhaust fan & not dust collectors.
In my opinion it should be 1 exhaust fan with dampers to isolate & name brand VFD to control the speed of said fan. This would obviously require a controller for the logic.
ABB in my opinion makes the best VFDād on the market.
Over the years Iāve worked on ABB, Danfoss, Eaton, Hitachi, Yaskawa & Toshiba just to name a few. I have some contacts with the local ABB rep and may be able to get a decent deal for the space.
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We are in complete agreement here!
Iād love to see some better extraction on the lasers, so I think weāre all in agreement (though Iām not sure if VFDs are strictly necessary).
That being said, itās probably time to branch this thread and wait for one of the chairs to chime in, because there are probably already plans in the works for exhaust in the expansion and all this might have already been brought up.
Iāve used two lasers in an industrial setting (They were both used 24 hrs a day, three shifts, 6 days a week). They had been in operation like this for 3 years by the time I got there. One massive open bed kern laser, one ULS laser analogous to Donner and Blitzen.
The main issues we had with the ULS laser was that it wasnāt receiving sufficient power in the configuration it was set up in. They were heavily abused as the operators were always new and turnaround was very fast (3 months was average). Maintenance was performed once a week (but they were running constantly). Software was much easier to run compared to rdworks. Lense cleaning was done infrequently but it was not required often.
Interior details were cut and SKUās were engraved on the ULS laser, indexing jigs were set up and it was fairly easy to index work (we used Corel draw to index and draw everything). This was all two years + ago, so I donāt remember the exact maintenance or usage, but all the head crashes we had did not require going into the guts of the laser and realigning the mirrors. I can tell you that the Thunder lasers would not have lasted in that situation, but maybe itās too much machine for the space. If the main issue is longevity of parts, weād want to nail down exactly what the issues were (mechanical vs system vs amount of use) and see if a US made laser can alleviate those issues. If it canāt then go with the Chinese lasers all day.
Do we log repairs anywhere?
That might indicate area where upgrading our current lasers would yield longer āupā times.
Food for thought.
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This, 100% would make worlds of difference in our setup. Iāve always found the smoke extraction lacking in our lasers for even moderately smoky jobs. This isnāt a jab against laser committee or the thunder lasers, just an observation. When we added air assist, we saw a huge increase to up time of the laser. A large scale increase to our exhausting would likely do the same as it has a whole list of tickle down effects on the machine.
Examples,
Much stronger exhausting would drastically decrease damage to the gantry and finer components of the laser in the instances of a material exhausting corrosive gases. This is a big plus as it lessens the effects of a possible new user error.
Secondly, it would drastically decrease the heaviest dust environments the optics and mechanics are exposed to, the times when the cabinet fills with smoke. This is doubly effective, because the dustiest times tend to be while the laser is running, meaning the dust is also interacting with the laser beam. This will lessen the issues we are having with the lenses breaking.
Third, it will lessen the impact laser has on introducing dust to the rest of the environment in and around laser. I know we give wood shop and metal the bulk of the crap for producing dust around the space and we are probably right in doing so. But, I wouldnāt be surprised if laser isnāt also adding a pretty good amount of fine particulate, given the technology and the use. @Brandon_Green may have more info on this.
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It is wonderful to see so many invested members with an interest in our DMS Lasers!
These are all great ideas. I highly encourage everyone with an interest in our Lasers to attend one (or more) of our upcoming Laser Committee meetings to advocate these great ideas and then after the Laser Committee meeting concludes, we welcome any and all help from fellow Laser advocates to provide hands-on assistance during our Laser Maintenance Day.
Laser Committee meetings are generally the first Sunday of each month at 11:00am, with Laser Maintenance activities commencing at noon.
We at Team Laser look forward to seeing you all there!
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@TBJK might correct me on this, but I believe what heās describing is a system with a single exhaust fan for all connected lasers. Each laser has an automated solenoid-operated blast gate connecting their exhaust to a common chimney. The VFD adjusts exhaust motor speed so as to ensure relatively constant CFM through each laser.
The lasers operate at negative pressures and remove minuscule quantities of material relative to most other cutting operations. While some measurable quantity might escape the laser cutters, I doubt itās enough to worry about.
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I think youāre right. I didnāt read carefully enough.
Sounds like a neat idea, and itād minimize the number of exhausts that need to get outside.
Layout realities might force north/south blowers, but I expect that we could avoid some of the challenges weāve faced with multiple blowers going out single pipes and resultant multiple-choice CFM.
While the laser operates at a negative pressure, that pressure is not sufficient to capture everything. Lightly smokey cutting jobs require leaving the laser closed for a minute plus to actually clear the smoke inside the machine. But, Iāve only observed individuals open the laser directly after their job has finished, cutting the negative pressure and releasing the smoke into the air in the warehouse. Think of it as every laser job exhaling a lung full of smoke into the warehouse. Maybe not a big deal at first, but when you look at the numbers, that is a lot. Secondarily, laser adds dust through the soot that falls off items and is spread around DMS. I agree this is not the largest source of Dust, but if everything else was gone, Iām sure we would notice it accumulating in the area.
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Thatās correct @ESmith. You keep the velocityās relatively constant & have room for upgrades/ more lasers in the future without a larger expense. Letās say that with all lasers on, the fan runs at 45 hz, add another laser & we could just increase the frequency instead of replacing or adding a fan. Additionally a VFD/VSD allows for a softer start, more energy efficient & less wear & tear on the motor/fan. Providing that its an inverter rated motor. Reliance, Baldor & AO Smith usually just build as inverter rated anyways but there is almost always a few out there that donāt make them that way.
Here is the downfall, I have not found any suitable information on the cfm or velocities required on the equipment. Every industry/ equipment Iāve dealt with in the past always showed the required infrastructure, IE submittals or O&Mās. I looked into the laser requirements for both Thunder & Zing. Neither had a cfm requirement for exhaust or even the cfm required for the air assist.
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Air assist on the Thunder lasers is (sadly) a pump inside the machine. Edit: this sounds like a rumour, I havenāt checked the air assist personally.
I would recommend using ULS, Trotec, or Epilog recommendations for CFM on similarly sized lasers. For example a ULS machine with a 24"X48" bed requires 1000CFM at the exhaust port. Big Thunder probably should have 1.5x that while Donner and Blitzen require .75x. The Zing requires 350-400CFM (https://www.epiloglaser.com/laser-machines/zing-laser-series.htm , bottom of the tech spec tab). Its still difficult to spec something without static pressures at the exhaust port, and thatās dependent on how the extraction ends up being routed inside the machine (which, while I expect to be shot down, Iād love to improve).
Edit: Those manufacturers specified 6" SP at the laser port. Randomly guessing that weād need 8" SP at the blower, that puts us at a 7-10HP blower, and is probably conservative. I love the idea but Iām pretty sure thatās a huge step up from what we have now. I assume at some point we have to consider make up air into the room as well.
They may ship with parts to operate that way, but I believe you will find that ours are all connected to shop air.
A single professionally installed huge fan with ducts / dampers would be great, although it would likely be over 100x more expensive, (ie ~$20,000 instead of $200 harbor freight blower). The critical spec is having high enough suction, meaning in the realm of wood shop dust collector style fans and not regular air handling fans which could produce the needed cfm but not the recommended pressure
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Also blade construction is of some importance. A good dust collector shouldnāt care if scraps of balsa, thin Baltic Birch, or foam core board gets sucked into the impeller. Other options may not be so forgiving.
Thatās in the range of what I was finding.
The good news is that if the committee decided to go this route it would be useful regardless of what brand machines we buy in the future and wouldnāt need to be replaced as often as the current lasers.
I do believe there are already plans in motion for fume extraction in the expansion, I was hoping @sixvolts or another committee member more familiar would chime in and tell us if we didnāt just reinvent the wheel.