Actually, I thought about it but decided I really didn’t want/need to. Not sure what I’m going draw up to use it, but I’ll find something.
Thank you very much, that is a realy useful information for me! You helped me to expand my knowlage quite a bit with that.
It helps me to understand the workings around drying, heat destribution and how advanced 3D printer guys handle that, and what is possible.
Wouldn’t a thicker plate help even out the temp differences, like cookware does?
Separate, newbie question on filament drying:
I’ve seen videos on filament aging and becoming brittle from moisture adsorbtion. Does that also happen to post-printed items? IOW, will the things I print today become brittle a few months down the road from being used in normal humidity environments?
It not a significant change in a printed item. Oddly, while on the spool, old PLA gets downright brittle, but in its printed form, it’s not really noticeable, or just barely. Not sure why that is. I’m sure it’s still absorbing moisture, up to its molecular limit.
Sure, but thick plates cost more money. Remember its more of a feature than a bug. People complain about waiting 10 minutes for a bed to warm up, so they designed a system that dumps heat in it super quick. They could have just left the warmup conventional and called it a day.
IMO, they are gonna have to slow it down anyway. It’s just too big of a draw on the circuit for the US users. I’m coping but, I can imagine in a fuller household, someone turning on a floor heater while the printer is running popping the fuse, or someone turning on a microwave on the same circuit causing a overload. I haven’t put a meter on the outlet to see the average draw during printing, but I assume Bambu’s number is pretty accurate (just over 1000 watts). That running wattage is still pretty significant.
If I’m right and they do decide to add in some code to recognize a 110v circuit and drop the amperage, it should slow it down enough to get a very normal heat saturation.
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how does your math handle ±2° at 0°C? maybe you will notice that working with % only makes sense with kelvin.
So its ±7° at 372,15°K => ±1.9%
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Moisture is not much a factor for printed objects. It is still absorbing up to saturation and there are knock-down factors to consider for engineering prints, but even then, moisture is not usually the biggest issue.
For practical applications, FDM porosity is more of an issue for functional prints sized to loads.
For longetivity, it is mainly a question of environment and material. In a nutshell: Do not use PLA in the garden. UV degradation can age it drastically within a year. Used in the house with modern windows, it’ll last much longer.
For longetivity beyond a few years, pretty much all other typical FDM materials are usable and have their strengths and weaknesses.
Regarding roll embrittlement, I have had that over the course of several years. However, from the glass like, stress based shattering failure mode, I expect to have been mainly from the outgassing of VOC’s as softeners were lost. At least for the rolls and tester packs I had packaged dry and stored UV protected.
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Loss of additives seems feasible. I know I’ve dried a brittle roll and it got a little better but never returned to normal.
This is weird, I’m sure its right but, I have seen firsthand, that PLA can hold up to UV reasonably well on occasion. Not sure if that is more of an additive thing or just luck of a certain situation. But what you say is a good rule of thumb.
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I think it is rather dependent on specific conditions.
A) I have a PLA foil backed coconut fibre mat as a temporary weed suppressor in the garden. It was supposed to degrade after 2 years but is still going strong. It is however still going strong as it is facing north.
B) I printed some PLA brackets for decorative purposes and forgot to replace them with the PETG versions. Being mounted on a fence, they were fully exposed to the sun, the wind, rain and snow and did not last a year. I do however expect that FDM porosity also played a role with water being trapped in pores and freezing overnight. PETG brackets in the garden however are still going strong after around 4 years.
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Robert Cowen reports warping in a structural test printed on his H2D. I set the time index to where he discusses it here:
Even though the test print showed less warping when printing on his H2D than on his Prusa XL, one could argue that it shouldn’t have warped at all.
I don’t want to blow it out of proportion. It didn’t look severe. Also, in almost all other respects, his video painted the H2D in a very favorable light.
Anyone else here have any more findings, either positive or negative?
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I’m not finding warping to be an issue. I had one part warp up by just a mm or 2. And it only left the bed by fractions of a mm. Very minimal warping. However, I did have my first failure (and accurate spaghetti detection is less than 2 layers). It was a very low surface area cross section (1.5mm) that I varied to the front left edge of the plate (just outside of the left exclusion zone). The reprint in the center left edge printed fine.
Failed test
Successful test
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I’m interested, why is it that it shouldn’t have warped at all?
At least for non-PLA filament, isn’t printing with the chamber heated at a perfectly stable suitable temperature by the PID chamber heater supposed to prevent warping? Or have I been brainwashed? H2D will be my first experience with a temperature controlled chamber heater. The X1E people are paying through the nose for its chamber heater.
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If you offset the bed temperature by 10C does this also happen?
What would happen, if i just always set 10 degees more bed temperature?
( sorry, i am a noob without a 3d printer)
Or do i have one because i payed for it already, and the printer just has a happy time traveling across germany?)
I’m not qualified, but eliminating warping seems like it would be very difficult to solve. You are taking molten plastic distributed anisotropically in the model and it’s going to cool and phase transition creating strains. Maybe if you could keep the model semi-plastic so those stresses would be relieved during printing? For even PLA that would be quite hot. It just seems like a hard problem, personally I’d think the best you could do is less warping.
On our industrial printers at work, I don’t recall ever seeing warping even for large models. The door is double-paned glass, probably an inch thick and the seal and interlock look like they belong on an auto-clave. So some combination of materials, software and chamber heating allows them to print virtually warp free.
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The heater isn’t heating from absolute zero.
Assuming a coolish 20C room temperature then it’s ±7° on a 80° delta => ±8.75%
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As far as i understand it is like this: heating the bed makes the filament stick better to it. So not anough heated bed makes spagetti. (Filament does not stick to the plate)
Thats all about basicly for pla filament.
( also the build volume temp is not allowed to be to high for that filament, and with closed build volume printer, you often have to open the door to print PLA)
For technical filaments it is more complicated, because there is warping.
Warping happens when the filament cools down to fast after printing. It also needs higher temerature to print and stick to the bed.
So if the technical filament cools of to fast while sticking to the bed it warps on the bed because the bed temperature could be to low.
If you dont print on the bed, so when you print a wall, the filament could also warp (on top of the wall that is not on the bed) there. So you have to set a build volume temperature in the closed printer build volume. That is important so that the filament does not warp from lets say 260 degree nozzle temp to 20 degree room temperature.
So if the room you print is heated, it only gets from lets say 260 degree nozzle to 65 degree temperature if the build volume is heated.
That drop is not to fast. The filament does not warp.
After printing you slowly cool it down from 65 degree to 20 degree.
Perfect part, no warping.
So what happens if the bed is not hot enough you can tell now, right?
What happens if the build volume temp is not stable or to low, you also know now.
You should also be able to tell me now what would happen if the bed temperature is uneaven and not the same everywhere.
You see now our problem with uneaven bed temprerature or if the sensor shows hotter temperature than the bed actually has?
(I also still dont have a 3d printer, still waiting for mine)
I reprinted after cleaning the bed and it stuck in the same place with no problem. Again… I’m finding this problem to be made up, or possibly just blown out of proportion. At least as of now.
That’s right. The idea is to print and keep the warp sensitive filaments near their glass transition temp. What that does is keep the extruded filament from shrinking and warping things while you’re printing. Then when printing is done, the model can shrink all together and not warp.
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You are right, i am sure that “problem” is nowhere as problematic as some some people make it. I would say that they try to make an inconvenience to a problem that is not realy there.
I am writing and watching that channel here to learn from people who know what they are doing when 3D printing.
I know that nothing can be perfect, exactly like no meassurement can be exact.
But what i try to find out is, what can i do to reduce printing fails while getting better quality parts (less warping) for technical filaments.
So i know that if i use that bed-glue i can get a greater chance that the support tree does not breake away from the bed.
I am now trying to find out if it could be better to always set the temperature 10 degree higher for a better chance of printing success without negative effects.
Because the sensor shows not the tempearture it should on the print bed. Or at least it could show.
Also the uneaven temperature on the bed temperature for sure could be reduced if i somehow manually preheat the bed and just waite a few minutes bevore i start the print, specially if i want to print on the edges.
I know this is not realy needed, because most likely the print will be fine. I know that, i have seen the reviews, and i believe you! But i still could increase the chances with maybe just that little modification.
Also the little warping with technical filaments is already realy good with the H2D.
So, what if the temp offset of 10 degree makes it even a little bit better?
That would be cool.
If that realy would work that well with the offset, bambu labs could impelement that if they just set the temp sensor in the bed so that it shows 10 degree less than it does now with a firmware update. I just have to take care if they do, that i stop setting the temp 10 degree hotter all the time.
If there are no side effects, why not?
Oh, sorry. Yes, adding bed temp increases the adhesion, but you need to balance it with the ability of the filament to stay firm enough to print well.
Sounds as though Bambu is suggesting preheating as well. But honestly, I don’t think people should fixate on this. It just seems like a non-issue. Keep your bed clean. Fingerprints probably account for more “adhesion” issues than anything else. Also, all printers have a significant difference in bed temps, edge to edge. 10C is not too far from very normal, IMO.
This is actually potentially good on the H2D because of the chamber heater. For the technical filaments, you are trying to keep the filament from cooling down too much and shrinking (warping). Some of these filaments will actually pull the plate off the magnets. So, it’s not always about adhesion.
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Thank you very much!
You answerd basicly everything now questioned here.
Preheat the bed, because also bambu labs tells us we should do that.
Problem with uneaven temperature on the bed solved if do as you should according bambu labs. But according your experience with the printer, that would not really be necessary because there was no problem for you if you did not preheat.
You can set off the temperature to +10 degree celsius, because that temp offset is not to far off and could help that the filament sticks better to the bed.
But more importent than that is to have a clean bed with no fingerprints on it because that could be more usefull than the temp offset.
You also said, that if you print with technical filaments it is more importent that you dont cool it off to fast because it could pull of the plate. At least more relevant than the points mentioned above, eccept the one point about the clean print bed without finger prints.
For me, everything seems crystal clear with that statemant.
I dont think there is anything more to add.