The importance of air assist

Actually, I would expect them to support every hardware generation in terms of replacement parts effectively indefinitely.

Since GF have chosen to market a product which will deteriorate with use, they have to support their customers by providing replacements for hardware until the last customer using that machine moves on, or provide a suitable upgrade path which makes that spare unnecessary.

I believe GF already has every intention of supporting us long term based on their conduct so far, but hypothetically if they were to tell me in a few years time that they no longer stocked replacements for their custom made Gen 1 mirror I would be extremely pissed off.

I’m not sure which machines you are referring to when you say “finding things for machines even one gen old can be a hassle”. I manufacture, support and repair industrial machines for a living, and the idea of a company that markets a machine and then declines to provide ongoing spare parts for it is completely alien to me. No company I have ever worked for or interacted with operates like that (even the companies that I don’t consider to be customer focused)

Edit to clarify: I’m only referring to custom made parts that we can’t get off the shelf elsewhere. GF only needs to ensure spares are available somewhere


It would be really awesome if they did fully support software and hardware indefinitely! But they have no responsibility to do so, and for a startup with a small team that kind of effort might not be feasible. So not doing so would not be some kind of black mark on them. They’re great people with a great product, but it’s important to keep in mind that despite having a record breaking funding campaign they’re still a new hardware company and shouldn’t be held to the same expectations as long established industrial hardware companies. This isn’t anywhere near what an industrial machine with years/decades of R&D and support would be, it’s a gen 1 hobby level machine at an insanely affordable price for the features they’re baking in. Don’t expect too much!

Don’t worry overly about replacement parts. While we don’t know specifics on the cameras so far, everything else is completely standard and replaceable, except the laser tube itself.

I would love to know what their windows are made out of, but the windows and mirrors can be replaced with homemade equivalents. Salt and hard drive discs respectively.

The only other components are bearings, motors and gears (all of which would be easily replaced with stock gear), and the drive board (which again, can be replaced if need be, and really would need replaced if the company went belly up on us all, since that would mean the cloud service is also gone).

The custom tube, ideally we can get the same custom tube sourced from the same vendor. If not, the custom bit about it was being shorter than most similar power lasers (as I barely recall). So the catch there if you cannot get the specific custom replacement is to put in a lower power laser tube that fits on the gantry.


I don’t really agree with that. What kind of company would release a product with custom made parts and then say “not our responsibility!” when you need a spare for your unusable machine in three or four years time? No company, startup or otherwise, would think that was a good idea.

None of this is aimed at Glowforge themselves; they seem like a company that plans to support their products properly and I’m sure they’re aware that supplying spares doesn’t have to be a financial burden. I was just surprised to see somebody saying it’s ok for companies to drop spare part support while they still have an entrenched customer base!

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Also the laser is TEM0. Many other hobby lasers use TEM1 so I think that type is more commonly available.

edited to add: Noticed at Maker Faire demo that the kerf is really tiny due to the TEM0 mode. Nice feature if you plan to do fine engraving.

I was wondering about the tube length myself. On Wednesday Bailey updated the FAQ to say “The Glowforge tube is custom made - it’s bigger than most desktop units (850mm) and has some modifications for longer lifetime and smaller spot size.” Most of the ebay 40W replacement tubes seem to be 700-750mm.

Longer than usual is no issue, since there is enough space for a third party replacement tube. Would suck if it were shorter than usual!

Love how some people are already hacking and replacing parts on a product that has not shipped yet.
Does make me wonder why some people ordered it in the first place.

If I was the builder, I would be a little insulted by this attitude.

If you have a direct question about a part being OEM, you should ask. I am sure one of the staff will give you a direct answer. To make an assumption about the GF biased on your past history with a different builder is starting to become a little annoying.

No one is making assumptions about GF. They might offer certain replacement parts they might not. But either way this machine will need cleaning, maintenance and the occasional new part, it’s the nature of the beast. If I were a new user I’d certainly appreciate more experienced users talking about upkeep costs that I might not have previously considered and budgeted for. And if I were the manufacturer I’d like to know about the concerns that experienced buyers and potential buyers might have, how people think they might like to hack/upgrade their units, etc… as it may influence future design and support decisions. That’s what user forums are for. Anyway, this thread has gone waaaaay off topic. So I’ll just leave it at happy lasing!

I wonder how custom the power supply has ended up being. It seemed to get a lot of intention. My guess is that we should be fairly safe for a couple years. After that, we’ll see. It’s not quite down to a commodified level that just expects full replacement every couple years. But as a new product, a supply chain for replacement parts will be important. The business model that is pitching an online catalog of designs and materials makes me think that the replacement parts will just be another aspect of that. If indeed the catalog becomes the primary revenue source, one would have to ensure that the machines are up and running to go through those consumables. And by the way. I regret I responded without realizing how off topic Inhad become.

Glad I had it backwards. I had remembered it was custom, but I thought custom shorter. Custom longer is AWESOME as it means you can easily swap to an inferior laser if forced to.

There is a bit more knowledge required to build your own power supply, but it is certainly something feasible for a large portion of the user base if needed.

Not sure if we are really off topic. The initial post was largely about machine lifespan and the need for proper maintenance. But I guess doing a few “reply as linked topic” out-shots would be appropriate.

Yup. That final surface between the third mirror and the material is the focusing lens! You really, really want that thing to be clean so maintaining positive pressure in the housing beneath the lens is really important to keep out the crud. In most machines that lens is a standard diameter and easy to source/replace. The GF has a super fancy looking effector head with cameras, motors and such baked in; so it’s unclear at this point how easy it will be to replace that lens without messing up calibration.

re: Power. Unfortunately, each time you bounce the beam off a mirror or pass it through a housing window you’ll be losing some power. And if they’re dirty you’ll be losing additional power as the extra material absorbs energy and scatters the beam further. You also lose power as the beam passes through the air from one end of the bed to the other. So, maximal power is usually at top left of the work area (where beam path is shortest) and drops off significantly at bottom right (where beam path is longest). If there is smoke in the cabinet that attenuation rate increases. Just some of the trade-offs in a flying optics configuration like the GF and many other desktop cutters.

edited to add: The GF should not be effected on the y-axis because the tube moves with the gantry. So power drop should only be noticeable along the x-axis. Also, fully enclosing the entire optical path (vs. only enclosing the optics) could almost completely eliminate this drawback of flying gantry configs. Nice design!

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Thanks for taking the time to address those questions - it’s good to get some experience-based knowledge while we wait for shipment.

Coated ZnSe.

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Looked up ZnSe. Interesting material. I’m surprised to see that it has 70% transmission at both 3mm and 6mm thickness. That seems counter-intuitive, or am I reading the graphs wrong? Or perhaps I don’t understand what is meant by “transmission.”

(Edit: I think I figured it out. Each surface has about a 17% reflectance, which accounts for the 30% or so loss, making the thickness of the material largely irrelevant.)

also, from the Edmund catalog:

“Zinc Selenide (ZnSe) is a relatively soft material that scratches easily and it is not recommended in harsh environments because its Knoop Hardness is only 120. When handling, apply uniform pressure and wear Latex finger cots or gloves to prevent contamination. Note: Special care should be taken when handling Zinc Selenide as it is a toxic material. Always wear rubber or plastic gloves to avoid risk of contamination.”

I assume we must take special precautions when cleaning this material. Will there be instructions?

That is where the term “Coated” becomes important. May influence the total transmittance, but should remove concerns about contact (Toxicity and scratch)


That’s good to know. Thanks!

850 mm is usually what is sold as 50W.

It’s not the lenght but the diameter you should worry about. If this is the same slim tubes as the typical K40 and larger, then they won’t last long.

The diameter decides how much gas is inside it - and that’s your duration or “on-time”. Slim tube, even with the best regeneration won’t last that long.

It’s a 50mm diameter tube (not one of the slim ones).