Itās a little weird to read this, you sort of read left to right to see how much airflow drops as static pressure increases. The key thing to notice is how steep that curve is on the lower right and upper left, your airflow wonāt sustain much restriction or redirection. (I am assuming the Glowforge puts ~12v to the fan so this graph is fairly indicative of our situation)
Notice that weāre talking about very small pressures here: the maximum static pressure for this fan at 12v is about a twentieth of a PSI (1.4 inches H2O is about 0.05 PSI). Itās really hard to find a fan in the same form factor that can push more pressure, check out my vacuum table thread for a deep dive into the available fans.
Add to this mix that any fan you choose to replace here needs to be about the same overall mass, or you might throw the clean corners algorithm off. If you want to use a more massive fan youāll need to figure out how to mount it off the head assembly and use a hose to direct things (you know, like a more serious laser does)
Absolutely!! I tried to address that in the second portion but probably didnāt make it overly clear or important enough. Enough resistance and youāll surpass what the fan will be able to handle.
I was probably making an assumption (and we know how that goes) that one of the approaches would be to essentially duct the air from existing components/fan, down to a smaller point, rather than ābroadcastingā like it is now. As far as the volume/pressure comment - pumps in general go HVLP (high volume/low pressure) or the opposite. Boyleās Law.
Thatās one of the things about the in-line exhaust fans, but also applies here since the fan type is the same (axial fan). They are generally suitable for high volume/low pressure but like your chart shows, they can stall pretty quick under pressure.
I think personally, if I were to try this, I would look at something like the air curtain set up at the front of the enclosure and block off or reduce the shroud from the existing fan (IIRC, you experimented with that, right?). I have no idea how effective it is on the little Epilog, but they continue using it, so it must not be not horrible?
There are certainly fans with much more power in that size, I have servers that have them and they are as loud (or louder!) as the GF exhaust fan when they spin up to full power, but the cables and connectors in the GF are designed for a low power fan and āupgradingā to a high power fan would almost certainly cause a failure of some type.
I think āfocusingā the airflow we have to the point of laser impact would be an interesting experiment.
Looking at the shape and space available below the GF laser headā¦ thereās not much space on top (before the focus sensor? See attached picture), but plenty below and on other sides.
I believe GF could engineer an air assist module similar to the Xtool M1 iāve linked the thread above: it works AWESOME.
Totally disagree @eflyguyā¦
Please try, with our Glowforge, to obtain such a clean cut (just layered with my ācheapā M1 with some very cheap amazon not-masked wood)
I paid more than 8500ā¬ to have a GF Pro in Italy and Iām getting crazy to (non) obtaining (expensive) proofgrade materials delivered locallyā¦
And cannot obtain any clean cut out of non-masked materialsā¦ If youāre able to, please share and make me happy (not painting the wood and not sanding itā¦).
But you same wrote āI think āfocusingā the airflow we have to the point of laser impact would be an interesting experimentā. This is exactly what the xTool M1 does. With these EXCELLENT results (useful even on foam materials to avoid melting out).
This is a simple 2mm plywood. With the M1 (10 optical Watt) you have no problems in cutting 1.5, 2, 3 and some 5mm in a single pass. For 2mm I use 100% power, 8mm/s, 1 pass.
But the air assist is needed (not only cleaner cut, but even more powerful cuts, as thereās no smoke to disturb the laser beam, and all the dust/soot are immediately removed.
If you tied in an 800 CFM exhaust to the far end of the exhaust hose you would be removing so much smoke so fast it would not have time to dirty anything. Even the 190 CFM Vivo fan plus the built in exhaust makes a big difference from just the built in exhaust alone.
At the moment the new place where I need moving the GF has no close windows, therefore Iāll need using a smoke purifier (that - in any case - has a strong air suction).
Nonethelessā¦ Iām sure that a little compressor blowing air just on the laser spot might turn far more effective.
I already added an external inline fan to my home-based xTool M1 (AC Infinity S4, 205CFM), but the results I obtain with the air assist mod, and a little compressor, are fa better.
You are painting yourself into a corner I think. The Hepa filters are very expensive and if they get filled they move air even worse. I have a Blu-Dri for industrial use that is 500CFM but it has a 12" intake and as I was able to use a window it gets rather minor use as much for kitchen smells and smoke as Glowforge room smoke (now rare)
Anything less than 200 CFM and you will need to change the filter so even 500 CFM to start will fill fairly fast. There are games to play with cheaper prefilters etc but that is a deep rabbit hole. There are some here who run their hose 30 feet (and really need a high CFM just for that) to avoid needing an indoor filter.
I expect that the Glowforge air volume needs will be far higher than the x-tool also.
At the moment I did already buy an HEPA filterā¦ not the GF original one, but the XTool one (that seems equal or better - same shape too, maybe same producer).
Unluckily at the moment Iāll have to keep the GF in my garage, that has no windows, soā¦ Iām not lucky with a close access to āfree exhaustā.
In the future Iāll try to move it in another place. Thanks!
I would think of your Glowforge as an indoor family pet. It can die if too cold or too humid even if you are not using it, and it will collapse if working while it is too warm. If the pet would not be happy, you will not be happy. The main working part is a glass tube full of water, and like freezing a glass bottle full of water it is not very useful after that.
Just to knowā¦ in this case do you add an 800cfm inline fan without removing the internal one (that spins at different speed). Might you have counter currents when you switch on the super external fan and provoke the glowforge one spinning? Or spinning more rapidly than expected?
And overspinning a brushless motor can destroy it.
* I havenāt heard or seen anyone who has destroyed their builtin exhaust fan this way.
Cue someone who will interject with ājust remove the inline fan, it works better and youāll be happy you didā. Yeah, yeah, Mr/Ms I-have-a-basic-machine. Not as simple if you have a pro.
Removing my broken fan in my Pro was a PIA, but worth the effort. Knowing what I learned about airflow over unpowered fans and propellers from my RC days, I felt it had to be done. I was running a 4" inline duct fan at the time, and the difference in debris build-up was quite noticeable.
Iāll admit itās not a simple task, and beyond what many GF owners should attempt. I wouldnāt put you in that category.
Cutting out the old-style grate also made a visible difference. Switching to a 6" fan, despite the 25ā of 4" ducting leading to it, made the biggest difference. I never ran a 6" fan with the failed built-in fan and stock grate, so I canāt comment on that.
I took my exhaust fan off and put a reversed pump from a blow up bed, between the outside of the exhaust and the outside. It has a stronger pull and sucks the exhaust out of the Glowforge. Itās amazing how much better and cleaner my Glowforge cuts now. It also helps to have a compressor running at about 10dpi with the hose converted to a small tube that I put in the front pass through slot. It stops scorches and always cuts clean through wood.
