What Is the BLTouch High Speed (HS) Mode? (Explained)

An automatic bed leveling sensor, such as the BLTouch, is perhaps the very first upgrade that you should add to your 3D printer if it doesn’t already come with automatic bed leveling, both due to the consistency and reliability it brings to bed leveling, and also due to the improvement it adds to the user experience by eliminating the process of manually leveling the bed.

On the other hand, even though an automatic bed leveling sensor is indeed automatic, as the name mentions, there are some manual processes involved in getting the sensor working optimally, such as ensuring that it’s installed correctly on the hardware side and also configured correctly on the software side.

Today, our topic will be one of the customizations that you can apply to the BLTouch, known as the high-speed mode, and while it isn’t a feature that isn’t commonly mentioned in the 3D printing community, it is one that can allow your BLTouch to fulfill its duty of automatically leveling the bed much more smoothly.

So, what is the BLTouch high-speed (HS) mode?

The BLTouch high-speed mode allows the BLTouch to conduct the process of automatic bed leveling in a quicker way by never stowing the pin and always keeping it in its deployed position instead, completely eliminating the time spent on the stowing and the deploying of the pin.

In the following sections, we will dive deeper into the purpose of the BLTouch high-speed mode to make things clearer, find out how to activate this feature, and finally, discuss the scenarios where it would be beneficial to utilize it.

What Is the BLTouch High Speed (HS) Mode?

The high-speed mode of BLTouch is one of the lesser-known features of the auto bed leveling sensor, as there isn’t a whole lot of mainstream mention about it that explains how the feature works and what it brings to the table.

The standard procedure of automatically leveling the bed with the BLTouch involves the deployment of the pin as the sensor approaches the print bed and its stowing as the sensor moves away, creating a scenario where the pin is deployed and stowed multiple times throughout the process.

While a singular stowing and deployment cycle doesn’t exactly take an extended amount of time, the fact that it happens a considerable number of times, based on the number of points that readings are taken from, can quickly add up to a substantial amount of time being spent.

When the BLTouch high speed (HS) mode is enabled, the process of pulling the pin back after each reading is eliminated, with the pin being deployed once at the start, and staying deployed throughout the entirety of the automatic bed leveling process.

This way, the time that would otherwise be spent on repeatedly deploying and stowing the pin is not required anymore, allowing the BLTouch to operate in a much quicker fashion and conclude the automatic bed leveling process as soon as possible.

How to Activate the BLTouch High Speed (HS) Mode?

As the BLTouch high-speed mode isn’t something that is commonly talked about, it’s also challenging to find clear instructions about the process of activating (and deactivating) it.

Below, you can find a step-by-step guide for the process of activating the BLTouch high-speed mode in Marlin firmware:

  1. Obtain the latest version of Marlin firmware from the official source.
  2. Open the Configuration_adv.h file with your favorite text editor.
  3. Locate the line “//#define BLTOUCH_HS_MODE true” by using the search function of the text editor.
  4. Remove the slashes at the start of the line. After this step, the line should read “#define BLTOUCH_HS_MODE true” without the two slashes at the start.
  5. Save the Configuration_adv.h file.
  6. Compile Marlin and flash the modified version to your 3D printer.

Once you’re done with the steps above, you can use the M401 H G-code command to verify the current state of the BLTOUCH_HS_MODE parameter, which will allow you to see whether the BLTouch high-speed mode is correctly activated.

If the M401 H G-code command states that the BLTouch high-speed mode is not active, you can use the M401 S1 G-code command to enable the BLTouch high-speed mode.

When Should You Use the BLTouch High Speed (HS) Mode?

Since the high-speed mode of BLTouch is not active by default, whether you should enable it or not is something to consider by weighing the advantages and the disadvantages to find out if it would bring any benefits to the 3D printing process in your case.

We recommend activating the high-speed mode of BLTouch by default, as it both quickens the 3D printing process by a considerable amount and, at the same time, protects the BLTouch from the wear and tear that occurs as a result of the pin being constantly pulled back and pushed forward.

While there aren’t any known disadvantages that come with activating the BLTouch high-speed mode, the documentation states that enabling it can cause the probing to fail in some cases, which is something to keep in mind to make the process of troubleshooting more straightforward in the case of such a scenario taking place.

Wrapping Up

The BLTouch high-speed mode is one that can definitely bring some significant advantages to the 3D printing process, especially considering that the standard operation of the BLTouch can be slow at times and increase the time it takes for the 3D printer to complete the print by a substantial margin.

To quickly recap, activating the high speed (HS) mode of BLTouch will cause the pin to always stay in its deployed position during the automatic bed leveling process, which will significantly reduce the amount of time the process takes due to no time being spent on stowing and deploying.

As permanently keeping the pin in its deployed position also reduces wear and tear that occurs due to the repeated stowing and the deploying of the pin by a considerable amount, we can consider enabling the high-speed mode of BLTouch to be incredibly beneficial for both reducing print time and ensuring that the BLTouch stays functional for a long time.

Happy printing!