That’s super interesting. But doesn’t the machine suck cold air in, even when idle? In a “warm” machine, I’d never run bitter cold air in there without worrying about cracking something (warm glass getting a blast of -9 F air on it… yikes). This could be the basis for their 40F minimum storage temp guideline to reduce extremes which could crack the glass - assuming GF customers have it plugged in and in idle mode 100% of the time.
Honestly, I dont understand at all who would leave the power switch on 100% of the time. Bright lights, and fans running give me 3 worries: electric bill, wear and tear on components, and noise! I always turn mine off.
Would be AWESOME to have a device I could leave inside the machine that would regulate temperature to a given setting (i.e. 45F). Without any fans sucking cold air in, this could be a solid solution! Reminds me of dog bowl heaters that you leave in an outside dog dish.
Since my GF is in a lower part of the house I can’t hear the fans at idle or see the lights. The electric use at idle is not very high. 41 watts on the Pro with the pump running. But understand why folks might want to power it down for convenience and energy efficiency.
However, as far as the wear and tear on components, the power on/off process is typically much harder on larger electronics than continuous running at idle. For a well designed piece of electronics it technically shouldn’t matter whether it’s left on or powered down. But the constant thermal change from hot to cool, hot to cool causes wear on the best of electronics, solder joints, etc. I tend to be in the camp of shutting the machine down only when it’s done for the day.
My basement with the GF is cold since I only heat the upper floors with wood. Its in the mid 40s down there right now. I have a brick that sits on the edge of my wood stove all day. If I want to use the GF in the next hour I’ll turn on the furnace and lay the warm brick and a remote temperature sensor at different ends of the crumb tray with the lid closed. Once the temp sensor works it’s way up to the mid 60s, about 15 minutes, the GF is ready to turn on. BTW: the brick is probably only about 150F and gives off a slow radiant heat for quite a while.
Same way my Grandparents used to get their beds warm on a cold winter night
So what I really really want is a way to regulate the tempurature of my GF interior to minimize thermal contraction/expansion during winter, and maybe so that it is always ready to go (warmed up like your brick). It’s not a production machine for me, so I’m fine having a few weeks of downtime a year.
That’s why I was thinking about the temperature regulated heating pad above.
Now “ready to go” could only work when the outside air temp is high enough (40-60?) since you don’t want to have a blast of cold air hit the warm components inside (causing hot/cold spots, weird expand/contract… boom). But could equally run the outside air through a regulated heat box, to avoid temperature differences… probably more complicated than I want to hassle with.
Received a new GF this afternoon. Has not yet been powered and there is definitely fluid and a few bubbles in the tube.
It was about zero at the local UPS office when it arrived, 13F in the afternoon when delivered. I quickly unwrapped it, dropped a wireless temperature sensor inside, closed the lid and put the box top back on. The sensor dropped to 32F and stayed close to that for hours. So the UPS hubs must have some heat.
Interesting. But clearly they aren’t caring about sub 0F temps, and the tube is not evacuated. So that tells us a story doesn’t it. That there is no danger at that temperature. Perhaps the liquid is non expanding
The company is not likely to give us any official insight. I say this with 27+ months experience of unanswered simple questions.
Each of us will make our own assumptions. Mine is that the company is not comfortable that the units will maintain reliability if someone were to store a machine at very low temperatures and turn it on before coming completely up to an operating temperature. If you store it at 40F and turn it on it may not operate until reaching a safe temp but isn’t likely to suffer from thermal issues. If you store it at zero F and turn it on then it’s completely plausible that something really bad might happen. But who knows.
If the company says don’t let the unit go below 40F then they aren’t relying on the common sense of their customer base. For every smart person on this forum there is an idiot thinking they are a smart person.
1.) But they should understand I’m asking about a factual physical property of the coolant (freezing point, and does it expand). Not asking the company to make a guarantee or contractually binding statement that could bite them. Maybe some geek talk about “yeah the lubricant can slough off the runs when too cold, and you dont want to delubricate your machine”. The degree of silence is stupid. I did write to support@glowforge.com and was copy/pasted the same 40F line from the manual, I asked for more info of what could possibly happen at lower temps, and got the wall (sorry we dont test beyond that). But maybe they all live in sunny california/seattle and just can’t relate to the polar vortex
I’m not even looking for how to get it safely powered on from 0F… Simply looking for safe (longterm) storage that wont crack parts.
2.) Beyond that, as a 2nd avenue of strategy… I’m happy trying to maintain 40F in my GF, which is why I brought up the heating pad.
I think the anecdotal reports here are telling me that for #1 the coolant probably doesn’t expand, and probably doesn’t freeze above -9F. Maybe it gets less viscous, who knows (who cares). For #2, I’d like a PID controlled temperature regulated heating pad, ideally a neck pad (or something of that size) that I can simply drape over the crumb tray with a cord hanging out, for the winter storage (not intended for running).
In addition, I would think you could also run a bead of silicone or caulking around each connection to further seal them, but use a rubber gasket of some kind if you’re using PVC hardpipe to connect to glowforge itself. I’m going to look at options for hard pipe, since my unit will be immediately next to a window. Im not a fan of flex…it kills airflow cause of all those ridges.
Just for the anecdotal record, mine worked it’s way through New York and Maryland just as the big storm hit - so while I can’t say what temps it was exposed to, I’m guessing it got pretty damn chilly.
My tube also clearly had fluid inside before ever being turned on, as evidenced by lots of bubbles. As a side note, whatever self bleeding system they have built in is seemingly very effective as all bubbles vanished within seconds of turning on and I’ve never seen an errant bubble work it’s way back through to the tube. Either that or they are all stuck in the heat exchanger!
Which is huge if you’ve ever had one of the Chinese lasers - the machinations and incantations necessary to get rid of the bubbles in those tubes (even to the point of tipping the laser on it’s side and moving the coolant reservoir (bucket ) above the machine. It’s just a PITA!
With the GF, it’s turn on and never worry about the problem again.
yep, if they get big enough. Gotta chase them out of the tube and it really requires a lot of PITA physical manipulation of the machine and the coolant vessel.
My GF was delivered on it’s end (like they all seem to be) and the tube was full of bubbles when I turned it on. They were gone before the machine had calibrated for the first time.
I got one of these from Amazon and tried it out. My basement is currently 58F so the GF is hovering at the edge of recommended operational temps.
I put the mat in and turned it on high. It says that is 30C. Leaving it in overnight and the GF parts & pieces are 66F measured via a laser thermometer.
So it does warm things up, just not as hot as rated - I expect that’s because it’s not under a sand base or something that it can soak heat into. But it’s only 14W at full power so no biggie on the electric draw.
I leave it in now while I’m not using the GF. (Just laying on the crumb tray with the cord coming out the front and the lid mostly closed on top of it.)
) above the machine. It’s just a PITA!