While this may be too early to ask - they are still tweaking a lot of the software, but question for @dan - when we do have our beloved Glowforge’s in our hands, will we be notified of any tweaks or updates, or at least to be able to look them up (the revisions) somewhere. Reason being if we have our notes stating certain settings work great for certain materials, then a modification or improvement is implemented and updated on our machine - will we be aware or just wonder why settings needed to be changed slightly on our end to get earlier result? Just curious…
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Although this has been asked a couple times before, we never got an answer from Dan. But lately he’s been a little more forthcoming with information, so maybe third time’s a charm! (My gut tells me we won’t know the answer until production units ship.)
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I’m just shooting in the dark here, but isn’t one of the differences between a vector engrave and a bit map the fact that for vector the laser is firing continuously, but on bitmap it’s actually firing over and over again? I can’t tell you why I’ve ended up with that perception, but I have. I could see where turning the tube on and off would yeild a different power response than a more or less continual beam.
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As regards speed and power I would be very disappointed if they changed after the official release. Adding special modes: okay. Changing something fundamental like speed and/or power I would hope only happens if there is an obvious bug that has to be changed. As to other functionality and change logs, well that is a company by company philosophy.
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Yeah. During an engrave the head is travelling back and forth along each line. The laser has to frequently turn on and off and vary the power as the engrave changes depth. For a vector it only has to strike once and then maintain the same power for the duration of the stroke.
Since the tube requires a high strike voltage to actually start and then has negative dynamic resistance once it’s running, I suspect that it requires some finesse to get one to reliably strike and run at the desired power levels, particularly when the desired power level is constantly varying and very low.
@palmercr I wouldn’t necessarily expect 1% engrave power to equal 1% vector power. It’s possible the minimum reliable vector cut power is lower than the minimum reliable engrave power. If that is the case then it would arguably make more sense for 0-100% on each scale to map to different power levels rather than have to repeatedly explain why the engrave power slider only goes down to 4%
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If you do, send the extra one to me! 
Yes, at least major ones. Doing that well requires someone from Rita’s team to spend meaningful time with the software team discussing every change, and right now, we’d rather deliver features sooner than have the software team spend their time on that. So we told pre-release users that it would be a little rocky, and here we go.
That said, this change was going to be announced because of its significant impact; it was a mistake that it was not.
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I wasn’t working on anything mission critical but was in the middle of recording a video when error messages popped up. Checked to see if anyone else was experiencing something major, assuming it was part of an upgrade. Logged off. turned it off, took a ten minute break and then turned everything back on. Worked great. Other than trying to understand the power settings for bitmap engraves (I thought the machine was broke since no pew at 100%) everything was fine. Kind of cool to see such a major change and while a little disrupting, the Glowforge took it all in stride.
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Thanks for the reply!! Of course I realize a LOT of software changes/updates are being tweeked now - which is why I was worried I may be asking to early. Appreciate the update and it obviously makes sense - lots of differences could happen in the next few weeks/months . ( Keep those PRU’s on their toes with surprise changes - 
)
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Maybe just to pre-releasers if need be. I mean, how else can a pre-releaser determine what’s a problem and what’s a “feature.”
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Yes I suspect it is not straightforward to make a variable power laser supply. I don’t know if the tube has to cut out and re-strike for each line or whether you can drop the current below the point it lases and then increase it again. I.e. just strike it once for each job.
For the negative impedance I think you add a ballast resistor to bring the total impedance positive. To do that without massive power loss you put an air gap in the EHT transformer that increases the output impedance without losses. That is about as far as my knowledge goes.
If I had a GF I would look at the cathode current waveform on an oscilloscope to see what it actually does.
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Amen.
Both strategies are useful in different circumstances. You can optimize depending on the target output.
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