There is no dispute that adding an auto bed leveling sensor, such as the BLTouch, to your 3D printer to replace the process of manually leveling the bed with an automatic and more reliable approach is a significant improvement to the printing experience.
On the other hand, the BLTouch automatically working doesn’t mean you don’t need to configure and optimize it since the sensor cannot fulfill its duty reliably unless you set it up correctly, meaning that it’s not possible to escape troubleshooting after all, even with an ABL sensor.
Today, we will dive into the purpose of one of the parts you can find on the BLTouch, known as the adjustment screw, that serves the purpose of physically configuring the BLTouch to allow it to deploy and retract correctly during the probing process.
So, what is the BLTouch adjustment screw?
The BLTouch adjustment screw is the black magnetic screw that holds the pin inside the body of the BLTouch sensor, and since it’s magnetic, it also acts as the electromagnet core of the BLTouch, responsible for pulling the BLTouch pin upwards.
Moving forward, we will describe the BLTouch adjustment screw with more details, such as where you can find it, find out how to use this screw to adjust and optimize the BLTouch as correctly as possible, and look at a unique BLTouch issue that you can solve with the adjustment screw.
What Is the BLTouch Adjustment Screw?
The BLTouch adjustment screw is a part of the sensor that many users aren’t familiar with, as it looks like something that’s just holding the sensor together rather than a part that users should interact with to configure the sensor.
The BLTouch adjustment screw is the black screw you will find at the top of the BLTouch sensor’s body, which is directly accessible from the outside of the BLTouch without the need for any extra steps to reveal it.
This screw directly attaches the pin of the BLTouch to its body and acts as the magnetic core responsible for providing the magnetic field that the BLTouch uses to pull the push-pin upwards to its stowed position.
As the adjustment screw of the BLTouch is a hex screw, it’s also worth noting that you will need a hex screwdriver or a hex key to interact with it since a standard flathead screwdriver won’t be suitable.
How to Use the BLTouch Adjustment Screw?
While how you can use it and what you can do with it is pretty limited due to the BLTouch adjustment screw being no different than a regular screw, the part plays a significant role in getting your BLTouch to work correctly.
You can use the BLTouch adjustment screw in two ways: to either remove and re-insert the BLTouch push-pin or to adjust the magnetic attraction between the screw and the push-pin by modifying the screw’s tension.
The first purpose of removing and re-inserting the BLTouch push-pin is pretty straightforward, as unscrewing the adjustment screw all the way out will release the pin from the body and allow you to take it out of the BLTouch.
You can then use this process for actions such as cleaning the insides of the BLTouch, cleaning the pin, checking for possible damage, or even replacing the push-pin if necessary and getting your BLTouch back in working condition from a non-operational one.
The second purpose of adjusting the magnetic attraction between the screw, which acts as the magnetic core, and the push-pin, which contains another magnet, is slightly more complex since the attraction level essentially determines the pin’s movement capabilities.
With this process, you can make the movement of the pin much smoother, preventing it from being overwhelmed by the magnetic force and getting stuck when it should move out and eliminating any issues that it may have with going back inside the body of the BLTouch.
Solving Unreliable BLTouch Deployment with the Adjustment Screw
While rare, it’s possible to stumble upon an issue that can trouble the BLTouch at times, where the sensor ends up performing erratic movements during the deployment process and fails to deploy as a result.
If you are facing the issue of unreliable deployment with your BLTouch, we recommend following the steps below to fix it with the adjustment screw:
- Note the position of the BLTouch adjustment screw. Taking a close-up picture should be helpful.
- Remove the BLTouch adjustment screw from the body and pull the push-pin out.
- Re-magnetize the adjustment screw with a strong magnet.
- Re-magnetize the push-pin with a strong magnet.
- Insert the push-pin back into the BLTouch, and screw the adjustment screw back into the position you have noted in the first step.
- Try deploying the BLTouch again. Then, if you’re still having problems, move to the next step.
- Make a slight modification to the adjustment screw in either direction and test again.
- Repeat step 7 with different tensions on both the looser and the tighter sides than the original position until the problem is resolved.
Since there isn’t an exact measurement to use while configuring the tension of the magnetic screw, getting the screw tension right and fixing the unreliable deployment of the pin can take a few tries.
As a result, we recommend making as minor adjustments as possible to the tension of the magnetic screw and running a test after each adjustment, which will produce better results than making sharp changes.
Even though the BLTouch adjustment screw may not look like something that you should be tampering with at first, it is actually a part of the sensor that can sometimes require configuration to ensure that the BLTouch operates correctly.
To quickly recap, the BLTouch adjustment screw is the screw located at the top (the black one in the middle) of the BLTouch sensor, which is responsible for holding the push-pin in its place in the body of the BLTouch and acting as an electromagnetic core for the BLTouch to pull the push-pin upwards.
As the adjustment screw has a direct impact on the BLTouch push-pin, re-magnetizing the screw or adjusting its tension can come in pretty handy in situations where you’re having trouble with the pin’s movement, such as it being stuck or it not going back inside, or even with inaccurate readings coming out of the sensor.