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Setup for a firefighting solution inside a heated chamber that doesn't destroy the printer?
Heated chambers, especially homebrew ones, might pose a fire risk if the printer inside has a really bad day and its TRP is defective or - oh horror - deactivated. We are dealing with a class A fire if it ever starts to smolder, so water is out. Many other firefighting measures - like an ABC extinguisher might destroy the printer. On a ferry, I saw signs that they had Halon firefighting in the machine room. But that stuff is near unavailable, the more fancy replacements expensive and a typical, pre made deployment system costs thousands.
Is there a way how one might set up a firefighting solution oneselves, using somewhat readily available parts?

Crazy idea: operating the printer submerged in inert liquid.

a $5 usb water pump can pump vinegar into baking soda, which produces CO2.

Firefighting Agent
One Halon alternative is the rather simple and cheap gas CO2. It is neither toxic nor hard to get: "60 liter" water-carbonation bottles are readily available over the counter to create soda water and contain some 200-300 liters CO2
Alternatives are Argon and Nitrogen, but those don't come in these small canisters and dissipate more quickly, but they also need the chamber to be gas-sealed.
Because non-flammable gases act by smothering the flames, it is vital that rooms in which such a gas firefighting system is installed are not rooms in which people are usually, and in case of a workshop, it might be required to disarm the automatic trigger while the door is opened!
Deployment System
Such a soda water machine also would deliver the most crucial parts of a deployment system: the valve. To activate it, a solenoid can be used - once current flows through the solenoid, the valve is pushed open and the CO2 will shoot out into tubing or piping leading into the build chamber.
The gas canister should under no circumstances be inside the build chamber's heated compartment but somewhat close.
Release System
Now we need a way to trigger the solenoid. I propose to use at least some redundancy in construction.

Manual Mechanical Override. This can be as simple as a lever that bypasses the solenoid and activates the valve manually. Also useful for functionality tests.
Manual Electric Override. Using a 9V block battery and some sort of latching switch/button. The solenoid is directly powered from the "reserve" battery now.
Automatic via a microcontroller. Using a small programmable chip, one could use a spare thermosensor inside the chamber to detect temperatures of dangerous levels. As a direct response, it triggers the solenoid to release the gas into the chamber and continue to do so for at least long enough to fully flush the chamber, even as the temperature drops with the injected firefighting agent. It might be best to also trigger an alarm, for example, a repurposed doorbell. If one goes for such a solution, an output of the current chamber temperature could also be integrated, though I strongly discourage from integrating the fire suppression as a part of the printer board!
Automatic via a thermal switch. More simple in design, a Normally Open Thermostat Switch could be used instead of a whole microcontroller. Such a switch could use the same power source as a manual electric override switch, and indeed, be mounted parallel to the same switch. The downside of a hard-wired thermostat switch is, that it sets a hardwired maximum chamber temperature. It'd be best to choose a switch with a reset-temperature that is as far from the trigger temperature as possible to ensure that the chamber contains as little O2 as possible. The availability of switch types here dictates the voltage of the system.

What about the chamber heat control?
Once the firefighting system engages, the chamber should no longer get access to fresh air. This could possibly be made by having a different solenoid push a shutter in front of the air intakes and/or by de-powering any chamber cooling fans.
Door Safety
A magnetic switch in the door should cut power to the solenoid, ensuring that only the mechanical manual override can fire the system.

Why not use the same type of valve as in sprinkler systems, activated by heat with no electronics?

@R..GitHubSTOPHELPINGICE because those are crazy expensive, one-use items, require water pressure behind them and are not available - unlike thermostat switches, thermosensors or... a stick of wax for the most simple version of a thermostat switch.

Aren't they just wax block under spring tension or similar?

@R..GitHubSTOPHELPINGICE no, the typical sprinkler is a glass vial filled with alcohol, explodes when heated beyond a point and then the water rushes through as a spring valve opens. They are not made for gas and are not easy to acquire.

@R..GitHubSTOPHELPINGICE another benefit of the electric is, it shuts down after the temperature dropped enough, unlike a one-use glass vial. 60 liters of air could displace the whole air in a room - shutting the valve automatically is a safety thing in this case. CO2 comes at a benefit here: it is so much heavier than air, that it keeps a breathable atmosphere above it.

The commonly available CO2 bottles actually contain ~230 L of room-temperature CO2. The "60 liters" refers to the amount of water you can carbonate with one bottle.

Is there any risk of the system freezing shut with solid CO2?

CO2 fire extinguishers are traditional for electronics when you don't what to mess them up.  They don't conduct electricity or leave a messy residue.  When the liquid CO2 expands out of the extinguisher, it causes dry ice crystals that cool the fire.

You probably want a motion sensor in the room to help prevent locking someone in the room to suffocate. Ideally you want one that distinguishes people motion from hardware.

@PerryWebb the setup is not to flood a full room but intended to flood the chamber. Much less room in there, more contained, but a motion sensor might be an idea.

Yes, I was thinking of a room filled with nitrogen.  The main advantage of a CO2 extinguisher is it is more than a inert gas.  It can cool the materials below their flashpoint.   Thus, it can extinguish the fire very quickly.


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Can RAMPS 1.4 be used for a 3D printer?
I am making a DIY 3D printer on a budget. So, I came across a kit with RAMPS 1.4 with an Arduino Uno which is really a great price. But, I don't know if the RAMPS board and the stepper driver (DRV8825) which it supplies, can be used to make a 3D printer. And also will it come with average quality parts as the total amount of that kit is 2999 rupees or 40 dollars. Here is a picture if needed:

RAMPS was made specifically for 3D printers and those stepper drivers were used often in 3D printers. Have you searched online?

To answer your question, yes, RAMPS 1.4 can be used for a 3D printer, but note that it is an outdated platform.
But...
From the supplied image can be concluded that the seller doesn't have a clue what is being sold in the webshop ( e.g. incorrect naming for the shield, 3 stepper motors and 4 stepper drivers?!?).
This is not a RAMPS set (RAMPS is a shield for an Arduino Mega 2560) but a CNC shield set. An Arduino Uno isn't typically the hardware used for a 3D printer (better suited for laser cutter), but you could use it. Also RAMPS itself is already outdated, there are other options for a bit more money.

With a limited budget and limiting the time and frustration spent on building your own first printer from scratch it might be more economical to buy a 3D printer kit; a kit has all the parts for frame and electronics to get started relatively quick. These kits are documented, have upgrades and have proven to work and can be used to build a better 3D printer (that is exactly what I did). Note that building a printer yourself is usually not more economical, large kit manufacturers have discounts on buying parts in bulk which you don't have. Unless you are building a printer from wood/MDF and have a lot of parts readily available a kit may be a more economical solution.

Trying to build 3d printer, before buying parts, the buyer should first spend amount of time reading, inspecting blueprints and detailed descriptions available online. For at least one complete 3d printer (probably FDM-type). There is number of different approaches to many things (e.g. what is movable, what not). Should study the BOM (bill of materials) to understand even how many motors, screws or meters of wires to buy. Not to find one late evening missing a rod, spring or nut. There is a lot of online sources to study to get an idea, try reprap.org.

Best and cheapest solution IMHO is to get a kit, it has everything from frame to electronics. It is hard to beat the prices as the manufacturers get great deals on the specific parts when they buy in bulk.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

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What can cause a 3D printer to catch on fire?
From what I've seen, you can take a typical extruder heater, apply the designated supply voltage without temperature control, and as long as the heater isn't contacting something with a flashpoint below the temperature the heater reaches, the heater will not catch on fire.  Thus, unless one catches the filament on fire, it seems that thermal runaway of the extruder heater wouldn't normally start a fire.
I'm not sure what would happen if someone installed wrong components, such as a 12V heater to a 24V supply. What are situations that could cause a 3D print to catch fire?

I know it's a bit out-there, but for the interest of people who like science and a laugh, a spillage of FOOF over the printer would cause it to catch fire: Things I Won’t Work With: Dioxygen Difluoride. "Catch fire" includes the filament, the aluminium, the circuit boards, and anything else.

In short:

The control board does not have thermal runaway installed
The heated bed connectors are loose and begin to heat up until the wires catch fire
The power supply or it's connectors begin to heat up until they catch fire
The modifications that you made to your printer were not well thought out resulting in a capacitor to explode (raises hand; that's happened to me.)

Note some connectors, definitely not all, tend to be self fusing.  See https://3dprinting.stackexchange.com/questions/10695/proper-hotend-heater-for-reprap-x400-pro-v3

That essentially says when modifications are made to the printer, or with a newly designed printer, it should not go unattended until one is reasonably sure of the modification or design.  It's also good to check cases that could lead to failure.

A normal hotend will not melt or cause fires, usually, see first video. However, if the power regulating unit fails as well and higher voltage is supplied (19 V on 12 V cartridge are enough) it can happen, see second video.
Fires are more likely caused by overheating wires, especially where joints are presents.
Hotend runaway does not cause fires from the hotend itself, but it could cause fire related to its wiring. Also, the uncontrolled temperature may make the hot end fan fail, worsening the situation.
Issues canbe caused also by a runaway on the bed and overheating MOSFETs.

Too much current on a wire can definitely cause a fire if a fuse doesn't blow and current control fails.  In such a case, shorted wires could cause a fire.

Aluminum will burn at its Melting Point 660.32 °C. That appeared to be the fire with thermal runaway test 2.

Another source of fire comes from connections, not the heaters themselves.
As the connection and connector ages, the electrical resistance of the connection increases.  Up to a point, this is not a problem.  A portion of the energy goes to heating the connection, and less energy goes to the heated element.  These are in closed loops, so energy is applied longer to compensate.
The connection is using the lost energy to heat itself.  This increases the corrosion rate, and also can cause plastic in the connector to flow, which relaxes the connection pressure, which further increases the corrodion, resistance, and heating.
This situation is unstable, and ends in one of three ways:

the extrusion hot-end or the bed don't get as hot, with implication on the print quality,
the connection opens, and the heated system simply fails,
or the worst case, where the temperature increases to the point where the connector housing, wire, heater PCB, or dust and fur on the connector catches fire.

The only real mitigation of this risk is to periodically check power connections for warming.  If a connection is warm, it should be watched more carefully.  If it is hot, you already have a problem and should fix it.
If you are concerned, focus on preventative maintenance, and on being sure that there are no flammable materials near the printer.  Don't put your printer in a simple foam case.  Consider the flammability of any enclosure components.
You might also consider adding a smoke and high-temperature detector connected through a relay to disconnect main power.  If a connection starts sputtering, you might detect it before the fire can transfer to your house.

Would you suggest re-making connections occasionally so that the oxide layer/dirt buildup is broken? Might contact cleaner products help?

I would not gratuitous reseat the connector.  If the connection is sound, there is already a gas-tight metal-to-metal connection.  Breaking that connection will increase the wear, and decrease the chance that the repeated connection is sound.  I would only remake the connection if it feels warm, or if the warmth increases.  Contact cleaner used at that time could be help.  If it continues, I would plan to replace both sides of the connector soon.  This is my opinion based on reading connector specifications and failure modes. I don't speak for experts, or any manufacturer.

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No stepper motor movement on Ender 3 Pro
I've recently updated my Ender 3 Pro to the latest Marlin 2.0 firmware and when I press autohome or try to move the axis, I hear a very quiet noise from the motors trying to move and then they just don't. I did get an error message about EEPROM when I first booted the printer after flashing but I just pressed reset and the issue hasn't come back even after trying multiple different firmware versions.

Hi, welcome to 3DPrinting.SE! This could we'll be related to an incorrectly configured configuration file, it is very hard to guess what is causing this with this little information.

Jacob, were you able to resolve your issue with steppers movement? If my response below helped you (and you can accept it to close question)? Or do you have any other explanation to share, like stepper driver settings in firmware? I am very curious of the actual reason. Also let us know if you still struggle with this.

This is a theoretical assumption, but I suppose that your steps/mm values are now wrong in the EEPROM - specifically that they are set to 0 (zeroed steps per mm)? Could you please use the LCD and navigate to Configuration > Advanced Settings > Steps per mm and check what values are set there? If there are zeros, could you set them to positive values (e.g. =80) and check homing again? Then save the changes using Configuration > Store Settings.
I just made the following test proving that this may be the cause. I set steps per mm for X=0 (executed G-Code: M92 X0 from serial terminal) and tried to move X. The stepper motor was enabled (quiet noise or hiss), but it didn't move at all. There was no additional feedback e.g. on LCD. Pretty similar.
If this is not the only broken setting, then option Configuration > Restore Defaults should reset the EEPROM to values defined in Marlin's configuration. I needed to perform Configuration > Store Settings to make it persistent. But this will reset many other values, so I would suggest writing down all current values from LCD before doing the reset, for reference in future (in case they were valuable). And you still may not see all of the settings on the LCD, therefore I would use G-code for this operation - see below.
These operations can be also performed from a serial terminal using G-Code commands: M503 to verify and copy the current configuration, and M502 followed by M500 to perform a factory reset.

In your platformio.ini file check the default_envs variable if it's mega2560 set it to your board type, this video from ruiraptor explains how to get your board type. It fixed it for my Ender 3.


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PMMA print distortion and inconsistencies
I am working on refining my PMMA printing process and I am trying to print as close as possible to the theoretical 100 % density of the material. I am making good progress and am slowing increasing the extrusion multipliers to try and find a good set of print settings.
I recently have run into an issue where the bottom ≈1/3 of the test cylinder is coming out rather distorted (see picture). The problem seems to sort itself out as the finish around the top of the cylinder looks fine. Do any of you have any experience with PMMA or have seen this problem before?
My initial thought is that it is heat driven and as more material is added it becomes less of an issue as there is more mass to dissipate the heat. For reference I am printing on an Raise3D Pro2Plus, for my prints I am running the extruder at 250 °C and the heated bed at 100 °C. I am eventually going to need to print rather large cylinders and would like an even surface finish along the length of it.
Test Cylinders, right and left show distortion on the bottom and the center shows a bizarre print where half of the cylinder was fine and half came out very jagged.

would love to know if you arrived at parameters that allow for satisfactory printing. I wrote a post (here: https://3dprinting.stackexchange.com/questions/16437/has-anyone-had-success-printing-pmma-filament-using-lulzbot-products) in hopes that someone had some wisdom to offer. Do you use any sort of heat-enclosure cage?

Commercial PMMA may soften already at 85 °C.
The higher you go away from the bed, the colder the air is, so the issues solves itself.
Try lowering the bed temperature, at least to exclude that as cause.
The second cylinder shows the very common issue related to uneven cooling. Probably your part cooling fan is blowing only from one side. Try using a better fan shroud or add a second part cooling fan.

Thanks for the insight, I will give that a try this afternoon. I'm not sure if something just blocked the fan for that run because I've printed about 10 of theses and that's the first time I have seen that issue.

Just an update, I think the heating bed was causing the issue like you said. Even dropping the bed temperature a few degrees made a good bit of difference.


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Accidentally printed a chocolate mold instead of the object itself
This is my first time printing 3D of any kind.
I'm not 100% sure what happened.  The quality of some of these first printouts has ranged between 'not great' and 'unrecognizabe glop'.
I'm testing with a Wiiboox Sweetin.
So far the quality of the printed items, using the demo designs and the company-included sample dark an white chocolate is a little underwhelming: The details are crude (rough edges / lack of detail) and the speed is slow (about 20 minutes to print something the size of your thumb).
Also tried to print a word created Blender (MacOS), exported to STL, imported to Ultimaker Cura where it was sized and positioned, sliced and exported to a .gcode file.  That printout seemed to be a mold of the object as opposed to the object itself.
Attached are two images, the 1st shows what was intended to print.  The 2nd shows what actually printed.

If you can see past the globs and blobs, and look closely, you might be able to make out why it looks to me like a mold instead of the intended item.
Side note I noticed that when the printer stopped printing (to move w/o printing), the extruder screw pulled back 10 - 20 mm, which seems excessive.
So some first timer questions:

What 3D printing controls might affect rough edges?

What 3D printing controls would have an impact on a speed of completion.  I know there's arm speed, but perhaps detail, maybe something else?

Is there some control -- something along the lines of 'invert' -- that would explain why I seemed to have gotten a cast instead of the printed object?

Is there a setting that controls how far back the extruder arm retracts when it moves?

Is it necessary to install a printer to compatible with Wiibox Sweetin in Cura?  Wiiboox isn't an option, but perhaps there's something compatible.  The printer comes with a CuraWindows.exe app (I'm on MacOS using Ultimaker Cura v4.8.0); there are two .ini files that come with that: 60ml0.6.ini & 60ml0.84.ini.

Thanks for any and all advice.

Even in "Mold" mode, sure looks like excess extrusion and quite possibly higher temperature than your source material "likes."

Excess extrusion seems right.  It looks like that while processing.  The temperature for white chocolate was set correctly (33°C) per instructions, but I imagine a little testing might make the a difference.  Thanks.

Cura contains a few different so-called "special modes" which changes what the software does with your STL. One such special mode is Mold mode which, instead of recreating the object, creates a mold for the STL. It appears you may have that setting turned on, so disabling it will cause Cura to work as intended.
To answer your other questions:

Most settings affect "rough shape", properly slicing your STLs to fit your printer and printing material is an essential skill to master in 3D printing. So there is no magic setting to get it all working, you need to tune all your settings according to what you want to print.

Your speed sounds fine, I can't speak for this printer in particular but print jobs taking hours or even days is not out of the ordinary. 3D prints in general take quite some time to complete.

Yes, usually it's called Retraction Length.

Yes it is definitely necessary to set up Cura to your printer settings because Cura needs to know the build volume of your printer and what flavor of firmware is installed on it.

Hi, welcome .  Just a comment - you appear to be a native speaker of a language which capitalizes nouns?  Try not to do so when writing in English.

Carl, do you refer to names of settings in the reseponse? All names of settings in Cura interface are capitalized. Btw. in current version 4.8.0 it is called "Retraction Distance" in the profile settings and material settings.

@DenisMuftic: Thank you for all the insights.  Very helpful (Use of caps seems fine too).  Re Special Modes > Mold -- That seems set correctly (Mold is not checked).  Considering the manufacturer-suppled .gcode files printed properly, and only the Blender-created file printed as a mold, I suspect somewhere in the process of exporting from Blender through Cura to .gcode some kind of inversion is happening.  Trying to learn and trouble-shoot.  Thanks again.

I suggest to use the "Preview" in Cura to inspect generated G-Code before running the print. It is the 3d viewer of printer head extrusion with many great functions - for example you can watch printing layer by layer, or even move by move, using vertical and horizontal scroll bars. Or benefit from checking Color scheme =Line type or View type =X-Ray view. There are also online gcode viewers. I like GCode Viewer (GCode Analyzer), having very interesting 2D view with similar scrolls.


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Improving print speed by adding holes
Let's say, I want to print a box for putting game tokens in.
It is an empty cube, but the top layer is missing.
I do not need full walls. It could have holes in it resulting in a mesh structured wall, like a fence or a shopping cart.
What pattern should I use for the best object stability and print speed?
What programs can I use to design this? (I do not want to manually add 100 holes in my design).

Do you already have a 3D modelling program that you are happy using?

bear in mind that the slicer will usually beef up the plastic around a hole, so you won't save as much time as you might think. I often hollow stuff out or "drill holes" in it, but that's more to reduce plastic costs than print time. Might look into meshmixer to post process if you don't want to do it  in the design phase, but really it doesn't take long to copy and paste a few holes into a grid; i can make 100 holes in a min...

Holes in vertical walls will make it take significantly more time to print, not less. Rather than being able to make a continuous path around the box on each layer, keeping the print head at the desired speed the whole time, the printer will have to run around each connected component of the layer separately, slowing down, retracting, speeding up to travel, slowing down at the destination, unretracting, and speeding back up each time.

simple example: a cube takes 23 minutes. The same cube reduced to a lattice of the same size takes 31 minutes (and bumps into minimum layer time issues).

Definitely the speed will be worse after adding holes (or the quality otherwise, if object's skin is printed fast), though some filament savings may appear.
But regarding "object stability": because adding holes will normally cause the slower printing (because of "skin structures" around holes), then walls might get bit stronger or have better layer adhesion (comparing to line speed, the material, the printing temperature, etc.). Then stability might indeed improve, especially when walls are thin. Or may be reduced, depending on the pattern :) Also number of walls may count (n * nozzle diameter) or lack of skin overlap - then printing holes would support consistency of the structure. Thus the question of stability may be significant. Construction sience would most probably lead to triangles.


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Anet E10 - Print above 270 °C or "maxtemp" error
Hoping to determine the reason for my inability to print over ~270 °C on my Anet E10.
To date all operation has been fine.  Attempting to move to a configuration that supports above 250 °C up to ~300 °C.
The control board is the default V1.5 with no changes purchased ~Aug 2019.
I use OctoPrint to interact with the printer.
When attempting to print with a temperature > 270 °C OctoPrint shows it is stopping with a "maxtemp" error. The same "maxtemp" error occurs if I just set the settings to 270 °C and let is sit there for a couple of minutes at most.
This occurs with or without the bed being heated.
I can print successfully at 260 °C with or without the bed being heated.
I have changed the thermistor to another 100k glass bead and a 100k within a canister. There where no changes in the ~270 °C "maxtemp" stoppage.
I have also changed the heater from what was there (30 W I believe) to two different new 40 W (resistance of about 4.1 Ω) without a change in the ~270 °C "maxtemp" stoppage.
The power supply seems not to be involved here since "maxtemp" stoppage occurs without the bed being heated.
I believe this is solely the reason that the control board has a "maxtemp" set at 275 °C. (but I don't know this since I can't find a statement that the V1.5 has this setting by default).
Is there something I am missing in this scenario?  It seems I need to flash the board with settings that have maxtemp > 275 °C - say for my needs ~300 °C.

Regarding the hotend, I neglected to mention and should have, that I have upgraded it to a Micro Swiss in preparation to print over 250 °C.

Your firmware has set a limit of 270 °C, normally, (default Marlin configured value) this is 275 °C. It appears that the Anet E10 developers have edited the value if you cannot exceed the 270 °C setpoint.
The configuration file for Marlin firmware has the following maximum temperature limit set for the first hotend:
#define HEATER_0_MAXTEMP 275

You can change this yourself, but, you need to flash new firmware, making sure that you're using all the correct settings for this printer model.
As a general remark (for others reading this), you shouldn't simply increase the temperature without changing the hotend (unless it is capable of high temperature printing), if the default hotend is lined with a PTFE tube, the PTFE can form dangerous/toxic gasses at elevated temperatures above 270 °C. But, in your case, an all-metal Micro Swiss hotend is installed that doesn't have the PTFE liner.

Note that the Anet E10 configuration can be found in the Marlin configurations zip file. For the 2.0.7.2 version, the E10 already has the hotend temperature limit increased to 305 °C.


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Filament doesn't retract for some travel movements using PrusaSlicer
The printer does not retract the filament for some travel moves result in scrape printing part as shown in picture.

This is my printer setting. Not sure which part be the problem.

I want my printer to retract the filament as I have set it to. Where to check and what could be the problem?

What is meant by "result in scrape printing part"?

The nozzle do rapid move and hit under layer. Sometimes the build plate shifted or the part popped out from bed.

Minimum Travel after Retraction is exactly what it says on the tin: if the travel after a retraction would be less than 2 mm, it does not retract. You'll want that to be short, but not 0, because retraction can lead to under extrusion at the start of a new line, and every swap from one shell to the next shell right next to it is classed as travel.

I think so but you see somw travwl got very long distant but it still not retract which so confusing.

Set it to line width and see what happens?

0.4 or slightly over should work fine.

Retraction does not cause underextrusion though; rather it's necessary to prevent it.

Okay then any way to make 3d printer just lift the nozzle up with no retraction?


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How to tell if PLA temp is too hot/cold
I was having an issue with flat sheets raising up during initial layers. I had my bed at 80 °C and kept raising it thinking it was an issue with cold. After reducing the temperature to 50 °C the sheets sit flat now but sometimes sections come loose. I ended up using masking tape and a glue stick and everything finally seems to print flat and keep adhesion. I am using 210 °C hotend but I might try lowering it to 205 °C.
How do you check if your printing temperature is too hot/cold or if your bed temperature is too hot/cold? None of the articles I read ever said that a bed too hot would cause PLA to rise but that's what happened.

Concerning the bed temperature, the correct procedure to determine the optimal one is https://magigoo.com/blog/3d-printing-perfect-first-layer-magigoo/

Too Hot
If you're printing too hot (with any filament, not just PLA) you're going to see stringing and blobs/oozing because the material is getting runny and exiting the nozzle in an uncontrolled manner. Because it's uncontrolled, you will also likely see artifacts showing up in your prints.
You might also see your filament burning. Instead of coming out of the nozzle as whatever color it should be, it will look brown or discolored because it was overcooked.
If your bed is too hot, you might start to see "elephant's feet" where the lowest layer(s) are being heated to the point of becoming soft and the weight of layers on top of them are pushing down, causing that layer to "pooch out."
You might also have problems removing the print from the print bed's surface because the plastic has seeped into the details of the print surface and hardened, essentially welding the part to the surface.
Too Cold
If you're printing filament that is too cold, you're going to run into an issue where the material being pushed into the hot end is not getting melted sufficiently. This means that pressure will build up in the hot end that can't be released through extruding material through the nozzle. If you've ever tried to pipe frosting using a bag/tip and the frosting was too thick, you'll know what I'm talking about.
When material is being fed into the hot end but not being allowed to flow out of it, something has to give. That thing is your extruder. It has a wheel with little teeth on it to grip the filament and feed it into the hot end (or bowden tube which leads to the hot end). It can exert a certain amount of force on that filament. When the hot end's back pressure builds to the point that it becomes greater than the extruder's force, it will start skipping.
Imagine trying to push a large, heavy object. Your feet will begin to slip as your the force of your exertion overcomes the friction between your feet and the ground. That's what will happen to your extruder. It will make clicking/clunking noises as the extruder unsuccessfully tries to push the filament through and the friction between the teeth of the gear and the filament is overcome. This is called grinding.
If your bed is too cold, you simply just end up with problems getting the print to adhere to the surface.

Warping
In your particular case, you're describing warping. Remember from physics 101 that cold things contract and warm things expand. Your print bed is warm, and so, too, are the first layers that are near it because the bed's heat is transferring up into them and keeping them warm.
Obviously, your active (topmost) layer will also be a bit warmer as it as just come out of the hot end. However, in general as you move higher up away from the printed bed, the printed layers get colder. Because they are getting colder, they are undergoing thermal contraction.
This creates a thermal gradient where layers go from greater thermal expansion to greater thermal contraction. The combination means that the bottom of the print will start to curl up (away from the expansion and towards the contraction).
This is not an issue with your printing temperature. It's a problem with your ambient temperature.
The easiest way to fix this issue is to put your printer in an enclosure. This isolates the air immediately around the printer from the rest of the air in the room. Because your heater's bed and nozzle are throwing out a lot of heat, they will heat up the print chamber quite a bit (mine typically runs over 30 degrees celsius, even in the dead of winter).
Because the ambient temperature in the print chamber is so much warmer than the outside air, that temperature gradient is much, much smaller. As a result, warping will stop becoming a problem.


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How to get Sunlu PLA to adhere to the printing bed?
I have a Creality Ender 3 that printed a spool of Sunlu PLA with no issues, so I bought a second to replace it, just in a different color.
The problem is I can’t get it to stick. The bed is level, I’ve tried printing at different temps, even adjusted the fan, but no luck. No matter what, the print still only partially sticks to the bed before eventually being knocked loose by the nozzle, if it even sticks at all. Mostly it just extrudes in a spaghetti ball next to the nozzle.
Does anyone know how I can fix this issue? I have tried everything!
Update:
More info for those who have asked:
I have adjusted the temps of both the hot end and the bed to various temps within what is recommended with this filament (200-230 and 50-90 C)
The bed is level
I have attempted prints with both the plastic and glass beds (glass bed has never been printed on)
Attempted to use hairspray
While the print is somewhat sticking, it now produces a glob of pla while making its first pass down, which it then hits and completely unsticks. I think the glob is caused by the pla not sticking to the bed from the very beginning but am unsure.
Hope this helped!

If I ended up overwriting someone's edit, then apologies - it was a timing issue.

Dear author, what exactly do you mean by "I have tried everything!" ?

Have you tried glue sticks, or a PEI build surface?

In addition to the other points made in the answers, I would make sure you go through a re-calibration for each colour of the PLA, even if the brand is the same. The methods used to achieve the colour will change the properties of the PLA. You've not mentioned the colour here at all.. but as an example, black and white PLA are very different. You might need to increase the hotend temperature for this PLA. For each PLA I redo the filament specific steps here https://old.reddit.com/r/ender3/comments/ec2i9j/how_to_calibrate_your_printers_esteps_and/

Dear "Anonymous _User", thank you for updating the question. Could you print with any other PLA? @Routhinator provided important information above. For the particular problem like "almost no adhesion", things like recalculating e-steps seem something to be done in the second row. Please review my updated answer below. I hope this will make you succeed.

Level the bed
Make sure that the bed is level. The nozzle must be equally high over heated surface, otherwise only part of the print will have chance to be smeared and adhere properly.
Clean thoroughly
First thing I do when I notice that increasing bed temperature does not work anymore, is washing the glass with soap or detergent. Some advice to use also isopropyl alcohol. My impression is that the main mistake is to use alcohol to wipe the glass instead of dismounting and thoroughly cleaning the glass from any grease. This is a bit more work, and for me works great.
Applying alcohol, brake cleaner or similar no-trace solvent could enhance the effect (as suggested by FarO).
Reduce the air flow
Disable fan for the first layer (or even more layers above).
Isolate the printer from environment - e.g. buy or build enclosure. Remove any drafts. Ensure that ambient temperature is not cooling prints down too fast (for example printing in garage or shed may fail until the space is heated).
Use kapton tape
You may like the idea to put kapton tape on the surface (only glass?). Wide kapton roll would be needed to cover big area at once, to cover the whole glass with good quality and in reasonable time. Created surface should be as ideal as possible, because any bubbles will cause later trouble, it is not easy but doable. The outcome is great. Any accidents with hotend should be avoided, and prints removed with some care, to remain tape undamaged as long as possible.
(I use 50 mm tape. And I save this surface for printing ABS, and only occasionally for PLA, because it sticks so well that I had problem to remove prints saving the surface, even after cooling down.)
Apply adhesive
You can use adhesives like hairspray, glue stick or even better a dedicated adhesion spray. It is suggested especially for larger parts, which tend to wrap without this kind of adhesive aid. There is no one good solution. You may want to experiment, starting from cheap and widely accepted to commercial and wildly advertised products, with regards to your local market. Look for example links at the bottom.
Expand line settings for initial layer
Make sure that amount of extruded material is correct. This mean proper calibration regarding settings like: steps/mm for E axis, flow rate. Small difference in amount of extruded filament will reduce the quality of the rest of the print. Bigger differences may ruin print at the initial layer, and for sure will spoil the rest.
Use slicer settings to increase line width for first layer. Values of 120-140% are standard settings for improving adhesion.
Slightly increasing height of initial layer may also help to overcome bed surface
roughness or slight leveling errors.
Decrease speed to 20 mm/s or less
Reduce printing speed for initial layer to 20 mm/s or even lower, and raise it carefully after trouble is really resolved. (In my opinion it is better to decrease speed to let plastic melt and stick, than to increase temperature.)
Modify temperature
The temperature of heated bed should be high enough to keep the initial layer of filament within glass transition zone. This usually means more than 60 °C for PLA (between 50 °C - 80 °C depending on contents). (I usually print at 70 °C, and raise to 80 °C when meet issues.)
Increasing the temperature of nozzle also may improve the adhesion. But it may also be temporary success, because of negative effects related to temperature differences, and for example cause wrapping - ruining especially wider prints. So decreasing the nozzle temperature is also an option to check, when wrapping is observed.
Experiment with more advanced techniques
If you are still failing, then try experiment following many advices around (contrary, but sometimes working). If the firs layer adhere to the bed, but problems appear later, then other advanced techniques may help - like slicing model with additional structures (brim or raft).
The best advice may depend on kind of heated bed, surface or environment. This checklist may be of some use: 3D Printer Bed Adhesion: All You Need To Know. Also there are many troubleshooting threads on the web, like this on Reddit: SUNLU PLA+ will not adhere to build surface, or; this on Thingiverse: SUNLO PLA+: does not stick..

If you can include the information (or a summary thereof) in your posts, and not just the link then that would be great. Linkrot would cause your answers to not be so useful in the future. See Are answers that just contain links elsewhere really “good answers”?. Also, inlining the links with the title of the webpage is also a good idea, as, not only does it look better and is more descriptive, it also aids searching for the page, should the link die in the future (see my edit for examples). Thanks :-)

Thank you for a remark. My response was primarily an advice from experienc, not just these links. Of course I understand the reduced quality.

Magigoo has a blog post about optimising temperature

In addition to the suggestion of cleaning the glass with soap (dish soap works very well) and THEN also with any alcohol or brake cleaner or similar no-trace solvent, you can use hairspray or glue stick for larger parts.

Just to add to octopus8 answer.
BED WARM UP TIME
Ensure the bed is at the temperature. I have a new Creality glass bed and noticed that when the temperature hit 70 degrees I would touch the bed and glass would still be cold. I would give it a good 5 minutes to warm up.
NOZZLE DISTANCE
It is possible that you were on the borderline of sticking/not sticking with the last batch and this batch is mostly on the non-stick side. Move the nozzle a fraction closer using Z offset. We are talking like 0.01 increments.


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How To Extrude These Cubes Array?
I apologize if the questions sounds stupid, I want to extrude these cubes only, I tried to select all, the freecad froze, and when I select the edges, it also say, no shapes selected for extrusion, can someone help.

CAD questions are always very much on the edge what we answer. What is the specific reason that makes this 3D printing related?

Suggest you post over at https://forum.freecadweb.org/ All the experts hang out over there. Just be sure to read and obey the pink banner when you post.


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How to fill these squares easily
I have an array with holes that I have to fill with different materials. My question is there is an easy way to fill them directly? I tried array, array draft and it is annoying to adjust them. In Blender, it easy to select the vertices and fill. Maybe it is a stupid question, but I am not really an expert.

Have you tried sketching a new object in a hole and arraying that object? That way you can have separate FreeCAD bodies to export for printing

The problem
FDM printers slice models in STL or OBJ format. Neither of these formats can transmit properties like Materials: they consist fully of surface definitions.
But... Multi-Material printing is a thing, yes?
Yes, but Multi-material prints use a simple trick: a single STL object can contain more than one surface definition, and you can slice more than one STL at once. But since slicers usually can't separate these from one another, they usually load multiple STLs and define the materials for each differently. For example, Adalinda has 4 different STLs, some containing multiple chunks of material, each STL corresponding to one printed color. And in this video Joel explains how printing that way works for an older version of the MMU.
So, to print the "cubes" in a different material, you'd need to have two STLs: The grid as one export, and the cubes as another. Then the Rest is slicing.
Way around?
Now, you might not have a Multi-Material Printer? Then you might want to design your item in parts that snap into place or have an interference fit. For example, you might print a plate with all the cubes on one side, and a grid that has a relief on the back where the plate goes. Then you print two times with different materials and push the cube part into the grate, some glue in between, and voila! It looks like one print from the surface. With a clamshell design, you might even completely hide the existence of the carrier plate - by having two grates that surround a hollow cavity for the cube-plate, and the cube plate pushes out into either of the clamshells.

Thank you guys! I figured out the solution, I will share in the post shortly.

If you are asking for print then it is yes with FDM (fused deposition modeling) with multiple extrusion you can fill with different material easily. But if you are trying to change the material in your digital design then you need to work on every hole in the array, especially with FreeCAD. If you find any, please update here.


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How to combine difference with concatinate object
The following creates an object with two slots:
 translate([-40,-40,0]) difference() {
     cube ([90,28,12]);
     translate([12,-.01,5]) cube([12.7,28.02,14.02]);
     translate([65,-.01,5]) cube([12.7,28.02,14.02]);

How can the first main cube be extended to be a complex object of the syntax:
cube([60,20,10],center=true);translate([0,0,5])cube([30,20,10],center=true);

and then use difference to create holes?

I fail to see why this question "does not appear to be about tools and applications of 3D printing", since it is about the use of a popular 3D CAD package. Voting to re-open.

@Mick CAD is only so far on topic as it solves a printing problem. You need to show how this operation you try is related to 3D printing - for example "cutting up" to print in parts. for "remove one part" you'd have to point out why this is not a simple CAD question but related to 3D printing, for example by telling something like "I want to print with 2 materials in my MMU. I have a model and want to put color A in most but color B in the cutout."

Both Mick and Trish raise very valid points. Dan, if you can edit your question to make it more applicable to 3D Printing then the question could be re-opened, otherwise we fear than we may become a "non-3D Printing related CAD" support site, if you see what I mean. See our on-topic page and CAD Questions - Review. Hi and welcome to SE.3DP, btw! :-)

The union syntax addresses this:
translate([-40,-40,0])
difference() {
    union() {
        cube ([90,28,12]);

        translate([20,0,20])
        cube([12,12,12]);
    }

    translate([12,-.01,5])
    cube([12.7,28.02,14.02]);

    translate([65,-.01,5])
    cube([12.7,28.02,14.02]);
}

It supports creating an object before the difference syntax is applied.


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Can carving templates be produced from G-code?
I am looking for a way to generate 2D horizontal templates for manually carving an object. My thought was to produce an STL of the model, generate the G-code, and then transform that into slices. Appreciate any suggestions for where to start. I'm not afraid of getting my hands dirty with python, R, matlab, whatever.

Carving decorative patterns?
If your templates needs to be used like one does a stencil, that's doable... but paper-thin is not as you can't make that with an FDM printer.
But if you allow 0.2 or even better, 0.5 mm thickness, it is as simple as making a vector graphic, importing it into a suitable CAD package, then extruding it to the relevant thickness, and sending it into the printer.
If you really need it to be thinner, invest in a vinyl cutter, and use the same vector graphic to cut a foil template for one use. Upside: you could use the vinyl to etch the patterns in metal.
Carving figurines?
Yes, that's possible too, even easier! Make a 3D model of the finished object in a CAD or 3D modeling software. Either cut up the model right there and export each slice as STL for the printer, or export the whole model and use a secondary software such as MeshMixer to do plane cuts onto the model.
The slices should be at least 0.5 mm thick to allow handling.
It might also be a good idea to use the same model and cut it from a cube, which then is sliced up - that way you get a pattern to press against the outside of the model.

I would approach following way. I saw interesting example of using Autodesk Fusion 360 to generate moves (G-Code) for carving in vertical slices. Fusion generated moves like for CNC tool in "parallel mode". You can see details in the video 3D printer cutting styrofoam like CNC router (software setup is presented at 11:00-14:30). Steps/settings important for manual work would be:

selecting parallel strategy
steup length and width of tool - reflecting "depth/width of slice"
check the simulation
create NC program - creating the G-Code file

I think that even if really working manually, the benefit of such approach would be that you focus on one layer/slice at time, and carve in one depth from the top of "material block" to the line defined be two points (the move in G-Code). The trouble could be actual number of such "G-Code lines": there will be probably too many of them, e.g. to measure each by hand and draw on the sufrface. But maybe this could be reduced with resolution (and quality). You could try to use any G-Code visualizer to project lines (of given single layer/slice) with beamer on the material sufrace.
The depth (real width of slice) could be controlled only manually, to avoid carving too deep.
The video uses parallel carving strategy to work in vertical slices. "Adaptive cleanring" strategy could be used to work horizontally.


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Help coding the MIN_POS and x/y probe offsets
I've read a lot of posts in regard to these subjects but I think that the advice is just so saturated it's hard to know what to follow.
I've had trouble with my bed min pos and x/y probe offsets ever since I installed the two fan version of the Hero Me 5. I followed the advice in the manual and uncomment MANUAL_Y_HOME_POS -9 to account for the width of the mount, but ever since then I can't get prints centered on my plate, and with the suggested probe offsets for the mount I used as X -60, Y -13, the BLTouch still won't probe the plate evenly, which is causing (I believe) the front left and front right corner to print unevenly.
I've tried remeasuring the offsets using the x and y coordinates on the printer and subtracting out the nozzle coordinates, didn't work. I tried printing a 100x100 mm square and measuring the left and right x differences and the top to bottom y differences, subtracting, dividing by 2, and updating that new value via M206 and M500, that didn't work.
I tried homing the nozzle to the actual x0, y0 position in the bottom left corner and using M428 to try and save that, but that didn't work. The only thing I was able to get to work and print fairly evenly (it's still off by a few mm on each side) is to use the code settings I have below and sending a M206 Y-11 M500 command which has it almost straight.
I tried updating that in the firmware and re-flashing but that reverted back to being uneven and my BLTouch still probes unevenly (bed visualizer is showing all green though. I also tried adjusting the Y endstop, but the bed started slamming into the end of the axis and grinding the belt a bit
So after that long-winded explanation, my question is how do I get my x/y to 0/0 in the bottom left corner, print evenly, and probe evenly, is it best to zero out everything and start measurements from scratch? I also ran an M48 test to rule out the probe and the returned values came back in line. My code is below for reference. Set up is Ender 3 Pro, 4.2.7 Creality board, Marlin Bug fix 2.0, BLTouch model v3.1, glass Ped plate, Hero Me 5 duct system.
Also just another side question, when you load new firmware, what is erased and what is updated? If I adjust these new values below, do I always need to load settings from EEPROM and save to over write everything old?
/ Direction of endstops when homing; 1=MAX, -1=MIN// :[-1,1]
#define X_HOME_DIR -1
#define Y_HOME_DIR -1
#define Z_HOME_DIR -1//
'@section machine// The size of the print bed
#define X_BED_SIZE 235
#define Y_BED_SIZE 235// Travel limits (mm) after homing, corresponding to endstop positions.
#define X_MIN_POS -6.5 (Previous defaults for both where 0 and 0)
#define Y_MIN_POS -11.5
#define Z_MIN_POS 0
#define X_MAX_POS X_BED_SIZE
#define Y_MAX_POS Y_BED_SIZE
#define Z_MAX_POS 250

#define NOZZLE_TO_PROBE_OFFSET {-61, -15, -0.60 }// Most probes should stay away from the edges of the bed, but// with NOZZLE_AS_PROBE this can be negative for a wider probing area.
#define PROBING_MARGIN 10// X and Y axis travel speed (mm/min) between probes
#define XY_PROBE_SPEED (100*60)// Feedrate (mm/min) for the first approach when double-probing (MULTIPLE_PROBING == 2)
#define Z_PROBE_SPEED_FAST (4*60)// Feedrate (mm/min) for the "accurate" probe of each point
#define Z_PROBE_SPEED_SLOW (Z_PROBE_SPEED_FAST / 2)

/ Manually set the home position. Leave these undefined for automatic settings.// For DELTA this is the top-center of the Cartesian print volume.//
#define MANUAL_X_HOME_POS 0
#define MANUAL_Y_HOME_POS -9//
#define MANUAL_Z_HOME_POS 0

G-code adjustment sent, M206 y-11 M500

Hi and welcome to SE.3DP. I've made some edits to improve the formatting and readability of your question. The easier it is to read, to more likely someone will be able to help you. Please refer to Useful things to check for when cleaning up posts in case I missed anything. Thanks

Question "How to center my prints on the build platform? (Re-calibrate homing offset)" describes what you should do. Furthermore, setting the Z offset in the firmware offset array is not the most common solution, Z offset can be set later with M851 and the MANUAL_ defines should be commented out, they are not needed.

@oscar, thanks for the feedback. Should I reset MANUAL_Y_HOME_POS -9 to 0 then go from there?


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Ultimaker 3 printing area?
I have designed a model with the dimensions 215x125x12 mm. According to my printer settings, the printing area of the Ultimaker 3 is 233x215x200 mm. But I can not get the model to fit. Why is that?
Here are some screenshots:

Yes that happens! It finds its source in various possible reasons.

The print bed is not square! There are cutouts caused by the print head;
The Ultimaker 3 has 2 nozzles, when you have 2 active, the effective print bed is smaller than with 1 nozzle active;
Using a brim or a skirt also makes the effective print area smaller.

In re-creating your example, the settings in your projects are not correct (but even if done properly, you will not be able to print it flat on the bed). Take a look at the image below, as can be seen your example still has a brim/skirt reservation, be sure to disable the second extruder (as shown by a cross X before "Generic PLA" at the top).

The only solution to print this on this machine is to print it upright:

Brim and skirt are disabled, only nozzle 1 is active, the other slot is empty. Is 215 mm too big?

@F_Schmidt Are you sure, your image clearly differs from added images in the answer. E.g. have you disabled the second extruder.

I created the image before turning off. After that I was able to fit a model with width 207mm


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Gluing paper to PLA objects
I have 3D printed in PLA a curved viaduct for a model railway (N gauge) and affixed inkjet paper using UHU glue. The layout lives in my garage and as soon as the viaduct goes into the garage the paper bubbles.
What adhesive can I use to prevent this from happening? I've had to strip all the brick paper.

The problem is probably the UHU glue having not had the time to cure through and interacting with either the PLA, the moisture in the garage, or the brick-paper's covering foil. Many of the metal-tube UHU glues - like "UHU Hart" - are resin-based and contain solvents that can interact with some polymers like the coating of the brick paper. Curing times can be up to 48 hours to cure.
I have had a very good experience with very basic water-resistant Wood Glue to both smooth over 3D-prints as well as attach layers of wood or paper to it. Most wood glues are made with a chemical that is the same or similar enough to those in Gluestick (usually PVA, sometimes PVP). These usually don't react with the fibers and surface of the NOCH-brand brick paper I know.
After having the glue dry thoroughly - for Express type wood glues that is about 2 hours - there is little to no chance that the two interact badly in the garage.

As a side note - Coating the entire PLA part first with an epoxy or similar to block moisture, and then spray-coating the paper after gluing in place can provide long-term resistance to all moisture effects.


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What specifics do models need to have to estimate the maximum acceleration my printer can withstand?
Previous questions on the topic of setting acceleration are:
How to theoretically calculate the maximum acceleration? (theoretical calculation)
How do I determine the acceleration value for my printer? (how to find the maximum value, in general)
The topic of the test model to use to stress the printer has not been touched yet.
So, when I want to test experimentally a printer according to the link above to have it skip steps due to excessive acceleration, what features does a model need to have for this to work?
To the extent it may matter, in my case I have a CoreXY printer with Bowden setup, so the stresses on X and Y direction are relatively comparable, the difference is only the weight of the X rods and holder (150 g max).
The firmware I use provides this model to test ringing:

Would that be suitable to stress-test the skipping of steps or should I consider making my own, and if, what features should it have?

"Which models" is overly borad. "What specifics does a model need to test for X" would be better

Does your printer have moving bed or just moving toolhead? Direct drive or bowden? These answers affect the order of magnitude you're looking for and thus to some extent test methodology.

@Trish edited accordingly

@R..GitHubSTOPHELPINGICE I think the question should be generic, but I added the information anyway

@FarO shifted focus a little to make it more generic - AFAIK, The main feature should be short movements perpendicular to a movement. Everything else is driving the acceleration settings up with each subsequent layer.


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What happens if you use high temperature PTFE tape with the heater block?
High temperature PTFE tape is rated up to 550°F, which is 288°C.  I'm wondering if it would be useful for components on the hot end to prevent oozing.  Has anyone tried it?

How would that help fighting oozing, please explain. E.g. when parking the hotend I want it to touch the tape.

might you have a leaky hotend? also "Does anyone" is not a good format generally... ´

@Trish: It would probably be more useful putting new parts together.  Teflon has low friction and allows the threads to slide tighter besides sealing gaps in the threads.  The tape layer would be best thin.  Once plastic gets in the threads, things are difficult.  It's easy to twist parts into if we tighten them too tight.

I've used a M6 tap to clear plastic out of the threads on the heater block.  Some printers use M7.

@PerryWebb To stop plastic getting as far as the threads, the nozzle should be tightened with no filament and the hotend hotter than you will print at. I couldn't find a 3DP.SE Q&A on that, so it would best to find a couple of videos/articles on the subject before doing it.

What type of hotend?

As Andrew stated: PTFE tape should not be needed.
Tighten the nozzle with the hotend hotter than you print at and also clean the threads with a tap if you need to.
To answer your question: it would stop leakage from the threads.

Whether this is even potentially beneficial depends on the type of hotend you're using. With one like the Ender 3 where the PTFE tube butts all the way against the nozzle, it's not useful, and if it seems useful it means your hotend is misassembled, since filament is never supposed to make contact with the top of the threads.
For an all metal hotend with flaws in the mating surfaces, it's plausible that it might help, but it rather defeats the purpose of having all metal (high temp).


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Can I use Creality bed on Prusa MK3S?
I need a Prusa MK3S smooth bed and I am not able to get it unless I wait for a few month.
But I can have a Heated Bed Cover for Ender 3/Ender 3 pro/Ender 5 3D Printer 235X235MM shipped to my door tomorrow moring.
Can I use the above Creality bed on MK3S untill I get an original MK3S in a few month?

Heaters won't match.
The ender3 is a 24 V machine. The Prusa 3 is a 12 V machine. Heater cartridges and Heatbeds are therefore not interchangeable.
Build surfaces can be adapted.
The Ender3 has a build surface that is a little bigger than the Prusa3, and thus you can, in a pinch, use an ender3 sized build surface and install it, possibly cut down, to fit onto the Prusa.


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3DTouch Probing Off the Bed X-axis
I have an Ender 3 V2 and a 3DTouch Makerbase sensor.
I have a problem with the bed leveling test.
The first test points are good, after that the nozzle try to test on the X axis outside the bed as can be seen in this video.
I hope you can help me

The problem is that the X-axis doesn't move back after the first 4 probes. This must be a 3DTouch not a BLTouch. What firmware are you using, or what did you change in the configuration files?

I tried several firmware, and I have the same problem. Marlin-bugfix-2.0.x and I followed the steps of Teaching Tech - Ender 3 V2, BLtouch & more, Smith3D-E3V2-2.0.x.14-5x5-SlowProbe, Marlin-bugfix-2.0.x and I followed Makerbase 3D Touch V2.0 Tutorial

Hi and welcome to SE.3DP. I notice that the video is stored on Whatsapp, and I wonder if they have a pre-determined life expectancy. That is to say, will the video be purged after a certain timeframe? If so, then your question may become a little unclear after that time period is up. If that is the case then it might be better to move the video to YouTube.


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What technics are you using to seal between the throat tube and nozzle?
Thinking this over, the best place to seal the hotend is between the throat tube and nozzle.  What are the advantages/disadvantages of an integrated nozzle and throat to make this seal?  Does a throat with a Teflon tube improve this seal?   Is it reasonable to cut a gasket out of 3mm ID 5mm OD Teflon tubing to make the seal for M6 thread parts?
I intend these questions to all address the main question to prevent a leaky hot end.

What you refer to as "throat" is more commonly referred to as "heat break". The term "throat", which is admittedly becoming more and more common, I believe originates in bad translation from Chinese.

A seal between the heat break and nozzle should be achieved by tightening them while the hotend is hot. After assembling the (cold) hotend, heat it up to somewhat above the highest temperature you will print at and then tighten the nozzle some more. When it cools down again, you will have a very tight seal. If the nozzle still leaks after this tightening then it is defective.
Using teflon is possible but will limit the maximum temperature you can use your hotend at safely and you won't be able to print some higher temperature materials.


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Ender 3 Pro Weak Prints after Cura upgrade
I'm getting weak prints on Ender 3 Pro with Cura after Cura upgrade.
Prints on my Ender 3 Pro have been good until I was forced to update Cura due to having to update the OS on my laptop.  Now my prints are weak even after using Infill 50 % from 20 %.
Upgraded to Cura 4.8.0.
I noticed that it seems my print settings were saved from the older non-working Cura version.  I went ahead and printed an XYZ Cube with the same settings from my older Cura version where prints were printing fine/acceptable.  It fell apart as I tried to lift it off the build plate so I printed a second XYZ Cube with 50 % infill from previous 20 % pictured below:

The above print is noticeably weak, with layers not bonding or maybe something else.
Below is an image of when an XYZ Cube printed with my older Cura version.  It is not perfect but it is much stronger without visible separation and actually noticeably heavier than the grey XYZ Cube printed with Cura 4.8.0 :

The green and the grey 1.75 mm PLA I use and shown in the photos are different brands but both printed very much the same with the older Cura version.
I'm thinking this is an issue with the new Cura 4.8.0 that I'm using as nothing about my printing has changed besides the new Cura version assuming that my original print settings were saved which it looks to me that they were.
Has anyone had a similar issue or is there a known fix for this?

Posting settings pics below:

12/28/20 :
Went to https://www.chepclub.com/cura-profiles.html and noted that they mention to use the Cura 4.8.0 Built-In profiles.  Below are two pics of test print while using Cura 4.8.0's Built-In Standard Profile :

12/29/20 :
Screenshot showing Nozzle Diameter (still using the 0.4 mm stock nozzle) & Flow @ 100 %.  Please let me know if these are not the correct settings you asked me to look in :

You are experiencing severe under-extrusion. Usually this is a filament diameter problem, this has nothing to do with the infill percentage. Please look into the filament diameter again (post screenshot) and check the extrusion multiplier.

@wallwalker You could try a different profile just to test, e.g. from chepclub.com. It is not impossible that a problem with the printer happened at just the same time as you changed Cura version.

@AndrewMorton Thanks. Tried a profile suggested by chepclup.com.  Still not good results.  Again, my printer was working perfectly fine until I was forced to upgrade to Cura 4.8.0.  After using my tried an true profile with the new Cura, I started getting these poor print results.

@0scar Sounds like you said my diameter setting is OK but I need to check if a flow modifier is active.  Would I check for that in Preferences > ?

If you install an older version, the cube prints fine? Also, did you measure the filament with a caliper? What worries me is that the latest added image suggest a different possible problem, the higher up the cube the worse the quality, heat creep? Please also check (long shot as that usually gives even more sparse filament deposition) that your printer is not set into volumetric flow printing: option in the menu of your firmware.

Issue Resolved : Some custom PLA setting in Cura was selected instead of Generic PLA .  Prints good again.

Total user error on my end.  With the new version of this app somehow I did not catch that material selected on the UI dropdown was set to some custom material and not Generic PLA.  Once I selected the proper material, all worked as expected.

There are three settings you will want to check in Cura to help with this.
Nozzle Diameter
Check your "Nozzle Diameter" if you've moved to a larger nozzle and haven't changed it in the new Cura version then it'll be under-extruding, or the default option may just be incorrect for you, most printers (Like the stock Ender 3 Pro) use a 0.4 mm nozzle.
Flow Rate
Flow rate usually requires a calibration test, however you should reference your old Cura profile for this, if in doubt, 100 %.
Filament Diameter
This needs to be set to 1.75 mm on almost every printer, which yours is.
If you can't get it figured out with these, generate G-code With two versions of Cura side-by-side.


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Ender 3 Pro not interpreting G-code correctly?
I have an Ender 3 Pro and I have been able to get it to work quite well, I installed a 0.8 mm nozzle to try the Vase mode in Cura. I re-leveled the bed and when I tried to print, I got some very strange behavior.
When it starts the "purge line" along the side of the bed, the Z-axis is too high and instead of going down the left side and back up, it will go down the left side and then from left to right along the back edge and then stop and then just extrude filament. If I look at the beginning portion of the G-code it doesn't look any different than the G-Code for the other models I have printed except for in the initialization script it set the Layer height and Min Z to 0.32 instead of 0.2 and the code for drawing the first 2 purge lines is identical. I tried printing an older file that worked correctly and I got the same results where it went along the left side then along the back side and stopped and just extruded filament.
It seems like something in the printer went wonky? What would cause this and what is the fix? A reset of some sort? And how is that accomplished?

what is the start Gcode? We can't tell you if that is excepted with the code.

It ended up being something with the printer, I powered it down, let it set a few minutes and then powered it up and it printed correctly. Is there a way to "reset" it without the power cycle, and is this something common? Thanks for the response!

yes, there are reset commands, no, a hard-reset works better - as to be able to send a reset command you need to connect the printer to a terminal PC, and that means you reset the printer by connecting it...

Is this something that is a common occurrence? Is there something that might have caused this?

I don'T know what might have caused it, but regular shutdowns are a safety measure and at the same time reset the printer.


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Ender 3 X Axis stops moving mid print at random times, only makes Y movements after
I have an Ender 3 that suddenly starting having an issue. The X-axis belt randomly stops moving when extruding the first layer. It doesn't always stop at the same exact spot, but once it stops, the only movements that are made are back and forth Y-axis movements.
I am able to freely push the carriage back and forth and there does not seem to be any binding. The printer has no issue performing auto home. I've checked all cables multiple times, on the external side and the internal side. The motor does not seem to be very hot if even warm at all. I've even tried swapping SD cards with a known working G-code/printer.
The only thing I haven't tried is swapping out the motor which I can't at the moment all my printers are busy, however, all the threads I've read mention the motor failure is the least likely answer. I'm not sure what would have caused this. All I've recently done is install a new cartridge and thermistor, and everything was working totally fine until I re-leveled my bed a few hours ago, and when I started a new print after leveling this started happening, and was giving me no issues prior. I can't find any similar threads, so I feel pretty hopeless right now.

One thing that would stop the X stepper is if the X-stop limit switch were stuck "on."
The main function of the stop switches on the three axes is to prevent the printer from continuing to attempt to run after reaching "zero" position.  If you trip the limit switch, the firmware will decide that you were at the zero for that axis, and offset the rest of the print, but if the switch stays closed, that axis will not move.  If I were designing the firmware, I'd probably command a couple steps movement toward positive in the affected axis, check if the switch has opened, and if not stop with an alert -- but especially in older 8-bit board versions of the Ender 3 there was a shortage of space for firmward features (they infamously also lack thermal runaway protection for this exact reason).
Therefore, check if the X limit switch (under the QR code label, just below the X rail) has gotten jammed; if not, unplug its cable and check with a continuity tester or multimeter to be sure it doesn't have an internal problem with the same result.


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Ender 3 Pro - "Pause at Height" automatically resumes after a few seconds
I recently bought an Ender 3 Pro, and while I'm super happy with it, there's one issue I'm having with it.
When I set "Pause at height" to a specific layer in Cura, the print will pause at that height, but as soon as it pauses the nozzle heats right back up and the print continues. It's like it pauses for only 30 seconds.
Here's the G-code for the pause command generated by Cura:
;MESH:NONMESH
G0 F300 X115.454 Y119.213 Z1.96
G0 F9000 X117.5 Y120.392
;TIME_ELAPSED:283.376298
;TYPE:CUSTOM
;added code by post processing
;script: PauseAtHeight.py
;current layer: 6
M83 ; switch to relative E values for any needed retraction
G1 F1500 E-10
G1 F300 Z2.96 ; move up a millimeter to get out of the way
G1 F9000 X190 Y190
G1 F300 Z15 ; too close to bed--move to at least 15mm
M104 S0 ; standby temperature
M117 CHANGE
M0 ; Do the actual pause
M109 S200 ; resume temperature
G1 F1500 E10
G1 F1500 E-10
G1 F300 Z2.96
G1 F9000 X116.604 Y120.251
G1 F300 Z1.96 ; move back down to resume height
G1 F1500 E10
G1 F1200 ; restore extrusion feedrate
M82 ; switch back to absolute E values
G92 E256.16251
;LAYER:6
;TYPE:WALL-INNER
;MESH:Super Curcan.stl

Anyone ever run into this issue?

I heard in a YouTube video that M0 (the pause command) doesn't work in the Ender 3 Pro firmware. It didn't work for me, either. I guess this confirms a stock firmware Ender 3 ignores the pause command.

I had the same problem (Cura v4.9.1). What fixed it for me was switching to a different Method.
On the screen where you set up the pause, the 3rd dropbox is Method. Set this to BQ (M25). That did the trick for me.
As I understand it, it mimics a pause like what you get with the pause you would execute using the menu on the printer.


text:
Are there quantitative means of measuring nozzle wear?
Are there quantitative means of measuring nozzle wear? What steps do you perform to measure this? If so?
I have some digital calipers, but I don't have much confidence in the measurements taken, as it's almost impossible to ensure the nozzle aperture is entirely free of filament residue.
The context here is I've recently been trying out some carbon-fiber-infused PLA filament, but I would like to keep an eye on how much it wears the nozzle and get an idea of nozzle wear rates. I can then work out if the mechanical and aesthetic qualities of the CF filament are worthwhile.

Why are people so fixated on does anybody?! please, formulate it in a way that is not I am poking with a stick at the anthill

Are you interested in evidence of nozzle wear? Then look at the Olsson Ruby site, they made a quantitative test on PC filament. Are you interested in scientific papers? There are non. are you into methods of measuring wear? or signs of nozzle wear in prints?

Do you have a microscope which you can use to take images? Also, you would probably want to examine the nozzle in situ rather than remove it every time.

Again, what do you look for? A grind-up curve? An estimation how long your nozzles survive? Olsson-Ruby did a test and it a brass nozzle survives about 0.5 kg of Carbonfiber.

examle: https://3dprinting.stackexchange.com/a/10886/8884 references the olsson-ruby picture.

With nozzles costing 40¢/ea or less, the additional cost of carbon fiber filament is probably around 10-15x greater than the cost of a few nozzles.

Good quality E3D nozzles for my Prusa i3 mk3s are considerably more expensive than 40c. However I'm more concerned about the time/hassle factor/risk of breaking something in the process of switching nozzles. Despite following all the instructions carefully, I managed to bend the heat break trying to free a seized nozzle, last time I attempted a nozzle swap and therefore wish to only replace nozzles when absolutely required.

Based on CNC Kitchen measurements,

the wear can be initially estimated by judging the overall length of the nozzle. Abrasive particles wear the nozzle very little on the channel (so the diameter doesn't change, for a while) but they wear out the outer surface in contact with the printed part, resulting in a shortening.
Of course, once the shortening gets severe, the diameter will increase because you reach the inner chamber.

And Olsson ruby got some numbers on that on their pare

@Trish I noticed after writing the answer that both 0scar and I already replied to a sister question: https://3dprinting.stackexchange.com/a/10886/8884


text:
Ender 3 Pro + SKR mini E3 1.2 + BLtouch doesn't work with downloaded bin file
I have a Ender 3 Pro V1. I installed the Bigtreetech SKR mini E3 V1.2 + TFT35 touchscreen + Antclabs BLTouch + a pre compiled bin from here .

the board works

the screen works

the BLTouch is erratic

A) it tries to exceed the X limits and makes the loud clicking sound while performing the bed leveling. it even tries to move past the X end stop switch.
B) when printing, it moves to the far right rear corner and extrudes off of the bed.
C) OctoPrint can no longer connect with the printer.

I think this is just a problem with how the bed size is setup and it identifying the limits of the print. I just can't figure out how to configure and compile a working bin file.

A) it tries to exceed the X limits and makes the loud clicking sound while performing the bed leveling. it even tries to move past the X end stop switch.

This tells me that the firmware you use is faulty - it has a faulty bed-size or home.

B)when printing, it moves to the far right rear corner and extrudes off of the bed.

This can be intended in the G-code, or bad homing, again, firmware home position.

C) octoprint can no longer connect with the printer.

This, again is a thing that happens if the firmware is not configured properly or flashed correctly.
You might have accidentally chosen the wrong firmware distribution - your config points to the Ender 3 - SKR Mini E3 v1.2 - BLTouch, not the Ender 3 v1.5 or v2 (slightly different hardware), and possibly adjust the proper homing position.


text:
Marlin: Switch Y to E1
I have an Anycubic Kossel with Trigorilla Motherboard, Mega2560+RAMPS1.4.
I'm using Marlin 2_0_bugfix
My Y connector is not working anymore so I would like to use E1 connector as Y.
I found a very good solution here but for me for some reason it's not working.
I did that modification what suggested in the pins_RAMPS.h file (for Y of course instead of X), then I compiled it with Arduino 1.8.13 and uploaded to my printer.
After that I flashed firmware then Y (which I plugged to E1) is not moving anywhere. I have never plugged anything to E1 before, so I think the connector port must be good and working.
What I am missing, what's my mistake?
What I did:
#define Y_STEP_PIN         36
#define Y_DIR_PIN          34
#define Y_ENABLE_PIN       30
#ifndef Y_CS_PIN
  #define Y_CS_PIN         44
#endif

#define E1_STEP_PIN        60
#define E1_DIR_PIN         61
#define E1_ENABLE_PIN      56
#ifndef E1_CS_PIN
  #define E1_CS_PIN        49
#endif

This should work, I've looked into the pins files for you. Is the stepper driver for E1 working? Is there a stepper driver installed? Just wild guesses. Swap drivers and cables to be sure.

You were right.I just figured out that the stepper was not working for E1, I will try it with another one. And maybe the Y connector is also good, only the stepper i faulty. Thanks for the idea, I tried a lot of thing without luck

If you followed the answer to switch steppers in firmware to the letter, but changing X for Y, this should work.
I've looked into the pins files for you and concluded that your proposed changes should work.
This leaves you with the following questions:

Is the stepper driver for E1 working?
Is there a stepper driver installed?
Is the cable working/not damaged?

Swap drivers and cables to troubleshoot the problem.


text:
Are control boards switchable?
I am interested in buying a larger printer, either a Sovol SV01 or a Sunlu S8 (or something else similar).
What I am wondering is, can the control boards and LCD displays be changed to better units later on?
How much are parts interchangeable?
Can the frame, steppers, extruder, base-heater and power supply be run with any control board which has enough outputs? How does this work?
I'm particularly interested in adding silent stepper drivers and BLTouch later on, neither of these units are very popular so not a lot of after market parts are out which list compatibility.

Yes. Stepper motors, heaters, temperature sensors, fans, etc... are all standard parts. Pretty much any control board can be used with the hardware from pretty much every printer.
Some more expensive printers might use more exotic parts (especially temperature sensors), but on the budget printers you're looking at I would be very surprised to find anything non-standard.


text:
Layer bending with first layer not sticking
I'm pretty new to 3D printing, so I'm looking for some tips with following problem I have.
I'm trying to print following model https://www.thingiverse.com/thing:4671256 on my Ender 3 v2.
But as soon as the print reaches the body and the first layer parts are attached, the print comes loose from the bed and the print will be dragged by the nozzle.
If you look at the picture you can see the bending of the front paws of the sculpture. So they don't stay sticked onto the bed.
I have changed the model to be 80 % in size, but also upped the bed temperature from 50 to 75 °C.
Running at 50 °C was even worse...
My printed 20x20x20 mm test cube was flawless by the way.

You've got an adhesion problem, there are plenty similar questions to find. Other than the bed temperature you could add a brim or add an adhesive.

@0scar true, but I also see lack of support in that area - there should some support structures already supporting in that area.

Try a Brim (the model is rather tricky on FDM), which can help with bad adhesion.
Your first laser appears coarse and not "smooched" as it should. This hints that you leveled either high, or you hit the portal off-angle. If it is just high leveling, a tiny turn "up" can help a lot.
The model has some rather flat overhangs, like the mouth, chin, under the tails and lower body. I suggest printing that with support turned on.
For PLA Filament, I use 200°C nozzle with 60°C bed, so unless you go far beyond that, your print should work.
Last words: that the model you chose was made with resin printing in mind, so you will use some details.

Thanks for the details @Trish ! I will first try the easiest part and change the model to have a brim added to see what happens. And I will read up on the rest of the suggestions.

Brim  and support together are the easiest, both are slicer settings.

Brim alone did the trick for this model, worked out nice. Again thx for the tips.


text:
Eryone Thinker SE ignoring endstop, gantry only moves down
I just got a Eryone Thinker SE and went through a lot of trouble to get it even working.
My first major problem was it would keep trying to ignore the Z endstop switch and go lower than it should be. I managed to fix it by doing a firmware update to it, and after a lot of trouble with getting the right temperature I started printing a test cube. I left it to print checking up on it every 30 minutes or so and near the finishing of the cube I came back to a screen saying something like "power failure, resume print", so of course I choose resume print but what it ended up doing was moving down, piercing the block on the print bed and then dragging it with it as it decided to home itself. So I immediately hit the reset button do it didn't try to push the block into the print bed.
But now when I auto home the printer, it jabs the print nozzle into the print bed, and it ignores the Z-axis endstop switch causing the right side of the gantry to go lower (due to there being no stopper on the right). Auto leveling just makes the gantry go down even further on the right still ignoring the endstop switch. The other thing is when trying to manually move the Z-axis, instead of going up (even though the LCD shows a positive number) it tries to go down.
Steps I attempted to do to fix it:

I attempted to do another firmware update, but to no avail this time.
I checked all the connections and re-seated them.
Scout the internet hoping someone with the same printer or board has had the same problem, to no avail again.

I should note when homing the printer, the normal action for it is to home X then Y, then Z. When homing Z however, NORMALLY, it will hit the switch move up and baby step itself to hit the switch and stop immediately when it touches it. But now, it will hit the switch, then just go down even more.
Video of what is happening here (Google Drive)
The control board on the printer is a Eryone 2560

You do a critical error in your order of operations: you home. Then you home again.
However, the firmware does not check if the switch is already depressed, it waits for a signal to cut out. But the signal is already not there. And as you will notice, it moves into X+ and Y+ before rehoming into 0, but does not do so in Z.
To prevent that behavior, you need to move the printer up a little till the switch no longer is engaged, then it will properly home the position.
The proper fix would be to alter the home-Z behavior to include a movement upwards by 2 mm before starting the actual homing. This does require a knowledge of Marlin though.

Ah okay. I get that part with the switch and not checking if it is already depressed. The normal action of the printer when homing is to home X and Y, and then it goes to home Z. Before, it would hit the switch then move up to un-depress the switch, then move down just until it depresses the switch again. But now, it hits the switch and just moves down further instead of going back up to hit the switch a second time.

@McGlowSticks that's how the firmware defined the "homeZ" button - I guess that's a pre-modified and not a self-set-up Marlin distribution?


text:
Issues with my print
I am currently making an ironman helmet but running into a couple problems.
Whenever I start my print it starts off fine, but then after it builds the bottom support and starts on the build itself things get really wonky. It seems that the build gradually builds away from the support and starts to float in the air.
I also see an issue where the model starts to curve and the filament isn't sticking to the support instead it makes a straight line through the curve.
Lastly the support column on the bottom left starts to clump up.
I am using an Ender 3 printer and Cura.

You are experiencing layer shifting, please check the tension of the X-axis belt, driver current.

A more elaborated answer is found here.

if it's starting to float, wouldn't that be pointing at the z-axis?

Awesome! This answers all my questions. I saw that this could be several different things, so ill do a few things and see what i can do to fix it! Thanks!


text:
Overhang Question
I haven't ran into the issue yet, but I am sort of expecting it to here soon towards the end of my print. Actually, I am not even sure if it should be something that I should be worried about or not.
Basically I have some overhang on a helmet piece (it's a vent piece) and I see that there is a 90 % degree overhang. It doesn't look too big but just curious if this should be something that I should be worried about. I forgot to add support in the vent, it's my own fault and I'm definitely going to fix this in my next print for sure, but do you all think it will fail if I keep the current print going?

I use Cura, Meshmaker, and I have an Ender 3 printer.
I'm just getting started with 3D printing so I wasn't sure if I should be concerned or not.

It looks like there are some defects in your STL as well, strange tessellation.

I'm having a hard time figuring out what the geometry of your part is. A picture from another angle as well would be helpful.

That depends on various parameters if an overhang will work or not, material, hotend temperature, speed, cooling, size of the overhang, etc.

Awesome, I'll let the print keep going then and see what happens, thanks!

@Kryreth - what happened in the end? Did it print ok without the support?

Many parameters will influence success. That overhang, as flat as it is and unsupported, will need to have support-structures enabled to become printable.

I wouldn't worry about that overhang. It should settle in a few layers. Just make sure you have a decent cooling fan on it.
Given the fact that you are making a helmet, I assume you are going to sand and apply putty to the whole thing at least 2 times and then sand in increasing grit. A little filing on that overhang will be an easy task.


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OpenSCAD linear_extrude from multiple path svg import
In OpenSCAD, I am trying to make a linear_extrude on a shape imported from an svg. The svg file contains multiple path. I would like to scale each path separately. I have tried the following code, but the whole import is considered a single shape resulting in the image below.
linear_extrude(height = 5, center = true, scale=1.2)
    import(file = "xxx.svg", center = true, dpi = 96);

How can I have each of the letters to have 'its own pyramid' ?
I know I could create one SVG per letter. But for simplicity sake I would like to have only one SVG file, as I want to create much more complex motives in the future. My final goal is to create stamps from SVG drawings.
Edit:
Alternative tried after Mick's comment (same result):
module pyramidChildren(height){
    for ( i= [0:1:$children-1])
      linear_extrude(height = height, scale=1.5)
        children(i);
 }

 pyramidChildren(5)
    import(file = "xxx.svg", center = true, dpi = 96);

I have tried to use the basic svg (multiple paths) and also to group each path (with only itself) without changes in the result.

Have you tried using children() on the object? This should allow you to manipulate each letter separately.

Thanks @Mick I didn't know about children(). I tried this after your comment, but it did not change the outcome...

children doesn't help. The import is a single child node not a sequence of components from the SVG.

Lame solution: creating stepped pyramid with offset. I realized that scale will not worked for motives with holes inside. Offset seems then more appropriate than scale for my application (creation of stamps)
It takes ages to render, but it could be enough for simple patterns. Any better solution are still welcome...
module buildPyramidalExtrude(height,maxOffset,nSlices){
    heightIncrement = height/nSlices;
    offsetIncrement = maxOffset/(nSlices-1);
    for(i=[1:nSlices])
        linear_extrude(height=i*heightIncrement)
              offset(r = maxOffset-(i-1)*offsetIncrement)
                children();
}

buildPyramidalExtrude(4,2.5,20)
   import(file = "Farm/cow.svg", center = true);

What you seem to want is not per-path scale but offset. This is an open PR in OpenSCAD and hopefully will be upstream soon.

Looking forward to see it in upstream!

One option is to use minkowski() to combine the svg with a cone. On the positive side, it gives a rather nice result, but the downsides are:

it's pretty slow
it fattens the bottom rather than shrinking the top, so depending on your needs you may have to invert the image, run minkowski, then invert again.

Another option is to convert to grayscale png and apply a blur with an external tool, then to import using surface() (the gray blur will become a nice slope). That will both fatten the bottom and shrink the top, but keeping only the top half should give the desired result.

Late to the question, but I'm working on a similar project as the question presents. My solution is to open the SVG file in Inkscape (version < 1.x) and use the Path to OpenSCAD extension to create a set of points for each entity.
The extension generates paths based on the desired extrusion height and places each set of points in its own module. In so doing, one can scale each individual entity and manipulate each one as desired.

Image from linked site.