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Auto Bed Leveling (ABL) Sensor Comparison – 3DMaker Engineering

One of the best upgrades you can add to a 3D printer to improve both performance and ease of use is an auto bed leveling sensor. Although they technically do not level the bed, they create a topological map of your bed and adjust the Z position of the nozzle to follow imperfections of your build surface for a more consistent first layer. 

The first upgrade we do to all of our printers is solid mount the bed (remove the bed springs) and add an auto bed leveling sensor. This allows us to level the bed once and never have to worry about it again. When you have a print farm, the last thing you want to have to worry about is adjusting bed leveling knobs on a large number of printers. 

Disclaimer: We currently sell a physical, hall effect type probe. We want to be upfront that we have not skewed our opinions based on this. The fact is, we tested each type of sensor extensively in our print farm and came to the conclusion that for our needs this was the most well-rounded option. Because of this, we decided to partner with a sensor manufacture to develop the 3DM Touch. We could have just as easily went with a capacitive or inductive style sensor which typically is much cheaper to manufacture.

If you Google “3D Printer Bed Leveling Sensors” you will find an endless number of manufacturers selling sensors of all shapes and sizes. To help simplify things we will break it down by sensor type instead of sensor brand. If you can understand the pros and cons of each of the technologies available it will help you determine the best one for your application.

Capacitive Sensor (ex. EZABL):

A non-contact sensor that can sense both metallic and non-metallic surfaces. This sensor works by monitoring the capacitance (how much energy the onboard capacitor can hold) which changes when an object is placed near its sensing face. It can detect any surface that has a die electric constant greater than air which should cover every build surface you will use (including glass). Another advantage of this sensor type is that it can probe extremely fast, saving you time during each print. Below is a basic diagram of how the sensor works.

One drawback is that while it can sense almost any surface, the distance at which it reads it will change depending on build surface type, temperature, and humidity. This is no problem if you only have one build surface and do not use an enclosure. If you plan to switch between different surfaces (ex. garolite, glass, PEI, polypropylene, etc.) like us, you will find yourself having to continually tweak your z-offset. Additionally, if you print in an enclosure where ambient temperatures vary, you will again need to adjust your z-offset.

Inductive Sensor (ex. P.I.N.D.A.):

This is another non-contact sensor, however, this type can only detect metallic surfaces. This means when the probe is analyzing a PEI spring sheet, it is actually mapping the spring steel and not the PEI surface you are printing on. This is usually not an issue, however, as the two surfaces should be relatively parallel with each other. If you are someone who likes to print on glass, garolite, or polypropylene—you may want to look for another option as these materials will not be detected. Although these sensors look very similar to a capacitive sensor, they work based on a completely different principle. They use the electrical principal called inductance. In a nutshell, an inductor coil in the sensor creates a magnetic field that changes when a metallic object is within its sensing distance. Non-metallic surfaces do not affect the magnetic field which is why the surface must be metallic.

Similar to the capacitive sensors, their readings are affected by temperature and humidity changes, so be prepared to make adjustments if you expect to see large temperature shifts. Some printer manufacturers, like Prusa, have done their best to use onboard sensors to automatically adjust for ambient temperature changes but in our experience it’s hit-and-miss. We have MK3S printers where we calibrated the z-offset at room temperature, put them in a heated enclosure, and found that the z-offset was then completely incorrect. If you are not printing in an enclosure, the temperature compensation seems to work fairly well for minor changes in room temperature, which is what we think it was really intended to do.

Physical-Hall Effect Sensor (ex. 3DM Touch+):

This is the only sensor on the list that actually makes contact with the bed as a means of detection. Because of this, it is unaffected by temperature and humidity changes like the other two contenders. It functions by using a plastic plunger (pin) and a hall effect sensor to detect your build plate. As soon as the plastic pin makes contact with the bed, it is retracted and registered by the hall effect sensor. Also, there is a built-in solenoid that allows you to extend and retract the probe via g-code which gives you plenty of clearance while printing. Below is a diagram of how a basic hall effect sensor works. Please note, the plastic plunger has a magnet embedded towards the top which is what the hall effect sensor is actually monitoring.

The main drawback of this sensor type is that it is slower compared to the other non-contact types. While there is only a few seconds difference per probe point, this can add up if you are doing a 7X7 (49 points) or greater grid pattern. The good news is that in Marlin 2.0 and newer, there is a feature called HSMode which allows you to probe nearly as fast as the others. The next issue is that it contains moving parts so, in theory, there is more that can break on the sensor. Luckily, the mechanism is extremely simple so there is almost no chance of it actually failing. The new plastic probe tips are also made to bend so if you accidentally crash it, you can simply bend the plunger back in place and get back to printing.

All testing was done with three brand new Prusa MK3S printers modified to accommodate the different sensor types.

Accuracy:

We wanted to test how well the three probes could continually reproduce a 0.24mm, single layer print without any other variables changing such as temperature or build surface types. We tested this by using micrometers to adjust the z-offsets until all three printers were printing a true 0.24mm thick first layer. Once dialed in, we printed the test print 5 more times and measured the thickness in several spots using the same micrometers. All of the probes were able to reproduce a 0.24mm thick first layer consistently without any deviation. If the inductive and capacitive probes are more accurate, they did not translate into any real-world results. Our conclusion: in a controlled environment all three options will provide accurate readings. 

Winner: Tie (Inductive/Capacitive/Physical-Hall Effect)

Versatility:

Our expectations: set the z-offset once and continually get a perfect first layer, regardless of the build surface type or ambient temperature. When you have several printers, you don't want to have to think about tweaking z-offsets every time your printer setup changes. This saves both time and frustration which, in our opinion, is the most important function of a bed leveling probe.  

On paper, the two non-contact sensors should be the most accurate. Their lack of moving parts and the sensing method give them a leg up (and was shown by Thomas Sanladerer on his YouTube comparison). However, when you throw in real-world variables such as different build surfaces and drastic temperature changes present in an enclosure, the Physical-Hall Effect type sensor comes out head and shoulders above the rest. 

Similar to the previous accuracy test, we set our first layer height to 0.24mm and then printed an object that was only one layer thick. We then removed the print and measured it with micrometers and made adjustments until it was exactly 0.24mm. Once the z-offset was adjusted to produce a true 0.24mm first layer, we then heated the enclosure to 35°C and hit print without adjusting anything. The 3DM Touch was the only one that was able to reproduce the same 0.24mm first layer while the other two failed to have a successful first layer. We did this 4 more times and the results were the same each time. The non-contact sensors just weren’t able to give the same z-offset reading with the large change in temperature. 

The next test was about switching between build surfaces. We did not test the inductive sensor as it can only sense metal and knew it wouldn’t be able to handle this task. For this test, we again adjusted the z-offsets on the two printers to produce a 0.24mm first layer using a spring steel build surface. After this, we then swapped out the spring steel build surface for a polypropylene plate. As expected, the 3DM Touch printed the same 0.24mm first layer while the capacitive (EZABL) sensor gave us a first layer height of 0.17mm which is an error of 30%. This is because even though the capacitive sensor can detect polypropylene, it detects it at a different distance than spring steel. If you plan on using different build surfaces, we recommend staying away from the inductive sensors as they will fail to detect everything except metal. 

Winner: Physical-Hall Effect Sensor

Probing Speed:

Both non-contact sensors are considerably faster than the physical probe. They don’t have any moving parts so no time is required to cycle the probe up and down. As mentioned earlier, Marlin 2.0 has introduced HSMode for the 3DM Touch which has helped increase probing speed, however, even then it will still be ~10% slower to probe the same number of points. If probing speed is extremely critical in your application, an inductive or capacitive sensor might be the best choice for you. 

Winner: Tie (Inductive/Capacitive)

Durability:

After testing each sensor type (multiple of each, over several months) none of them showed any signs of having issues with durability. Some argue that the 3DM Touch sensor has moving parts so it, in theory, could wear out. We are confident that your machine would need to be replaced long before the plunger mechanism wears out. The old BLTouch probes had metal tips that would get damaged if you crashed your machine but the newer ones all use “breakaway” plastic tips that deflect if crashed. 

Winner: Tie (Inductive/Capacitive/Physical-Hall Effect)

Because the 3DM Touch is a lot more complex in its design, it tends to also be the most expensive. There are also very few manufacturers who produce them which is also a driving factor of cost. Quality capacitive and inductive sensors, on the other hand, can be found for less than $10. This is approximately a third of the cost of 3DM Touch-type probes. If you are on a tight budget and still want to add a bed leveling probe to your machine, both the capacitive and inductive sensors will be a great choice. 

Winner: Tie (Inductive/Capacitive)

All three sensors seem to do a more than adequate job as long as you don’t plan on switching build surfaces or changing ambient temperatures drastically. Casual users who are on a tight budget will likely be extremely happy with either a conductive or inductive type sensor. 

If you are a 3D printing “super-user” and have the extra budget, we would recommend the 3DM Touch as it requires the least amount of calibration in the long run. It handles everything from build surface changes to large temperature variation without ever needing to do any additional calibration.  

Each user is going to have a different set of requirements for their printing needs. For us, the 3DM Touch made the most sense; for others, it may be a capacitive or inductive sensor. We hope that this article helps clear up any uncertainty about the various options available and will help you make an informed decision for your own needs. If you have any questions about areas we did not cover, please feel free to contact us and we will do our best to provide answers. 

-3DMaker Engineering

Best Auto-Leveling Sensor for 3D Printing – Ender 3 & More – 3D Printerly

Getting the best auto-leveling sensor for your 3D printer is a valuable upgrade for better first layers, leading to more successful 3D prints. This article will go through some of the best auto-leveling sensors that you can get.

The best auto leveling sensor for 3D printing is between the BLTouch and the CR Touch. They can both be used on a variety of surfaces and have great accuracy for leveling. Some people have gotten better performance out of the BLTouch, while others think the CR Touch is superior due to its optical sensor.

You’ll want to know more about the best auto-leveling sensors, so keep reading on.

Best Bed Auto-Leveling Sensor for 3D Printers – Ender 3 & More

Antclabs BLTouch

The BLTouch (Amazon) is an automatic bed leveling sensor for 3D printers that help users achieve accurate 3D prints. It has become one of the most popular auto-leveling sensors for 3D printers and works excellently well with the Ender 3 and many similar 3D printers.

When attempting to produce a good print, a user encountered difficulties with his 3D printer. He expressed dissatisfaction with the manual leveling of the bed, which he claimed was time-consuming and inaccurate.

He chose the BLTouch sensor after a series of difficulties, and praised the product’s quality and recommended it as the first modification for anyone interested in 3D printing.

One user who has the Creality CR-10 said it was compatible and worked well to improve their printing quality and success rate of 3D prints. Putting together the auto-leveling sensor wasn’t too difficult for them, as long as you follow a good guide and have the right firmware compatibility.

It worked flawlessly after a simple installation and configuration.

Someone who used the BLTouch for the first time found that the BLTouch worked very well and was well worth the money to not need to constantly level the bed.

Many people experience issues with getting sensors to work such as a capacitive sensor. One user opted in to use the BLTouch sensor instead and said he got flawless first layers afterwards. Even when a bed is uneven or warped, it still works very well.

You want to avoid purchasing BLTouch clones because some users have noticed that they were incompatible with glass. They then went on to order the BLTouch and stated that nothing beats the real deal.

Some of the negative reviews of the BLTouch are from getting these untrustworthy cloned versions.

Pros of the BLTouch

  • There is no need for an extension cable to connect the sensor to the main board.
  • Installation is simple and it’s easy to use
  • Light and relatively cheap
  • BLTouch kit includes a mounting bracket and a 32-bit cable
  • Works with a variety of materials
  • Strong community support

Cons of the BLTouch

  • Accuracy can be negatively affected if you have other devices that have an electromagnetic field
  • Setup can be difficult if you don’t have the right firmware or a 32-bit board
  • Has a plastic pin which can break if you have an issue

You can get yourself  the Antclabs BLTouch from Amazon for a competitive price.

Creality CR Touch

The CR Touch, like the BLTouch, is a 3D printer automatic bed leveling sensor manufactured by one of the most well-known 3D printer manufacturers.

After having difficulty adjusting the first layer after a few prints, a user decided to purchase the CR Touch (Amazon) after reading positive reviews. He stated that the accuracy was excellent and that the update provided genuine satisfaction.

Most users find the instructions fairly simple to follow but it can get complex when it comes to changing firmware and things of that nature. As long as your 3D printer is compatible and has the capability to have an automatic leveling sensor, it shouldn’t be too difficult.

One user said he needed two attempts to install the correct firmware, but overall took them less than 30 minutes to complete on their Ender 5 Pro.

After reading positive reviews, a user decided to purchase a CR Touch. He had previously encountered a warped bed and tried flattening it with tissue paper and a magnet, which worked but required adjusting the first layer after a few prints.

The entire installation for the CR Touch took them about 45 minutes, including the firmware upgrade. The Sensor’s accuracy appears to be very high, and the results of multiple bed level tests were consistently positive.

After revealing that the BLTouch is similar to the CR Touch, a user claimed that the CR Touch is super easy to install and has an easy firmware update via SD Card.

The difficult part for this user was opening the printer control box on the Ender Max, which was not designed to be easily accessible. Following a quick installation, the start G-Code should be updated to use the sensor.

Another user who is a beginner and 3D prints with an Ender 3 Pro said many good things about this sensor. They initially struggled at first with a few test prints, and stumbled across the automatic leveling sensors.

They chose the CR Touch over the BLTouch and found that it was very durable and has a fantastic metal probe feature. Installation and setup was simple.

The BLTouch has a plastic tip which can break off, so many people choose to go with the CR Touch instead.

Pros of the CR Touch

  • Has a metal pin rather than a plastic pin, making it more durable
  • Uses an optical sensor which has great accuracy
  • When not in use, it retracts electromagnetically

Cons of the CR Touch

  • Firmware is known to not be the best
  • Heavier and larger than the BLTouch
  • Can’t get a replacement probe, but the metal is harder to break
  • Some users have complained about the sensor rattling

You can get yourself the CR Touch from Amazon for your auto-leveling needs.

How to Fix Ender 3 Auto Bed Leveling Not Working

When attempting to level your bed with the BLTouch Sensor or CR Touch sensor, you may encounter issues that result in a poor user experience. Understanding your printer, sensor, and other elements that contribute to practical usage is necessary.

The BLTouch and CR Touch auto-leveling sensors are excellent. However, users frequently encounter specific issues. This guide will provide some troubleshooting tips for the most common problems.

  • Follow the instructions carefully
  • Enable the appropriate firmware
  • Avoid clones
  • Observe your wiring system
  • Test probe first
  • Ensure compatibility with your 3D printer

Follow the Instructions Carefully

One of the biggest reasons why people have issues with automatic bed leveling on their Ender 3 or other 3D printer is because they didn’t follow the instructions carefully. Some users have mentioned that manufacturers don’t have the best instructions to follow.

I’d highly recommend finding a good YouTube video to follow because they are more thorough and simpler to follow along with. This video below by Teaching Tech on the BLTouch is a great one that many users have had success with.

Some 3D printers might not have the motherboard capable of using an auto leveling sensor such as an 8-bit board on an Ender 3 for example. You’ll need to upgrade your motherboard to a 32-bit one to be able to use the BLTouch or CR Touch.

Enable the Appropriate Firmware

You may have difficulty leveling your bed if the firmware is not updated. To avoid this problem, download the latest firmware and obtain relevant information to make the process less stressful. Additionally, firmware upgrades aid in getting the best performance from the probe.

Creality confirmed that if you do already have a BLTouch enabled firmware on a 32-bit board, that’s all you need to make the CR-Touch work, so you won’t need to do much on the firmware side of things.

Avoid Clones

Users typically have negative experiences with clones due to their inaccuracy. Purchasing the original sensor rather than the inferior quality is the best option to avoid spending more than required for repair and additional costs.

You can look on the side of the BLTouch for a code to verify if your sensor is a genuine one.

Some users have mentioned that a lot of these sensors are identical and just re-branded or licensed out by manufacturers. Cloned BLTouch’s aren’t going to have the same level of quality control that the genuine ones have though, so you do have an increased risk with the quality of it.

Websites like AliExpress sell clones which people have had much success with, so it’s really up to your personal preference and risk tolerance.

Observe Your Wiring System

One of the many issues that prevent auto bed leveling from working is a faulty wiring system. Examine your wiring system thoroughly to ensure that all cables are connected to the correct socket.

Test the Probe First

Before mounting the probe on the printer. Running a series of tests helps you confirm its performance rather than having a disappointing operation experience.

Check out this video comparing both the BLTouch and CR Touch sensors for accuracy using the M48 G-Code command.

BLTouch Vs CR Touch

Functionally speaking, the BLTouch CR Touch are identical but there are some differences in the design and durability. The CR Touch does have better durability because it has a metal pin instead of a plastic pin.

This can be a benefit and a negative because if you have an issue with the pin crashing into something, the steel pin could break something, while the plastic one would warp or break off.

They both operate using a different type of sensor, the CR Touch said to be more accurate, more durable, and less affected by heat and vibrations. They can both work on any 3D printer since the operation is similar to a BL Touch.

The issue with the CR Touch mainly seems to be with their firmware not being up to standard. Many people recommend to upgrade to the Jyers firmware because it has many improvements over other firmware, one of which is easier leveling.

Many people have done tests comparing the two but results do seem to be mixed.

This video below has the BLTouch performing better, but others have the CR Touch outperforming the BLTouch. It could be due to cloned or defective units.

SuperPinda Vs BLTouch

The SuperPinda is an auto-leveling sensor that makes 3D printing bed leveling simple and consistent. The SuperPinda has a high-quality sensor designed for Prusa 3D printers. It has a unique calibration area on the bed to help with leveling.

The BLTouch is a touch-based 3D printer bed leveling probe that enables automatic bed leveling regardless of your 3D printer’s print surface.

The BLTouch is a contact-activated automatic bed leveling sensor that uses a flexible probe to measure the gap between the build plate and the nozzle. The BLTouch sensor works with various surfaces, including glass and blue tape.

The SuperPinda is ideal for detecting changes in the magnetic characteristics of materials, whilst the BLTouch is suitable for many surfaces and operates effectively without recalibration. The SuperPinda responds to change based on the properties of the materials placed in front of it.

It’s hard to compare the SuperPinda with BLTouch. They are incredibly efficient in their operations and have received more good feedback. However, there are some little differences between the two sensors to consider.

  • The BLTouch is powered by a physical (Hill Effect) technological system, whereas the inductive system power the SuperPinda.
  • SuperPinda has excellent metal compatibility, whereas the BLTouch is compatible with all materials, including glass, metal, and plastic.
  • SuperPinda is less expensive than the BLTouch
  • SuperPinda is ideal for Prusa printers, while the BLTouch works efficiently for most other 3D printers

everything you need to know

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