<p>You need to change the constant value(s) in your <a href="https://github.com/MarlinFirmware/Marlin/blob/1.1.x/Marlin/Configuration.h" rel="noreferrer">Configuration.h</a> file of your Marlin version from:</p>

<pre>
// Set the number of grid points per dimension.
  #define GRID_MAX_POINTS_X 3
  #define GRID_MAX_POINTS_Y GRID_MAX_POINTS_X
</pre>

<p>to:</p>

<pre>
// Set the number of grid points per dimension.
  #define GRID_MAX_POINTS_X 5
  #define GRID_MAX_POINTS_Y GRID_MAX_POINTS_X
</pre>

<p>This shows that to go from a 3x3 grid to a 5x5 grid you only need to change one value. Do note that you can set <code>GRID_MAX_POINTS_Y</code> to any value other than <code>GRID_MAX_POINTS_X</code>; replacing <code>GRID_MAX_POINTS_X</code> in the line with <code>GRID_MAX_POINTS_Y</code> to 4 would yield a 5x4 probe grid:</p>

<pre>
// Set the number of grid points per dimension.
  #define GRID_MAX_POINTS_X 5
  #define GRID_MAX_POINTS_Y 4
</pre>

CC BY-SA 4.0
2021-05-26T18:38:34.520Z
"You need to change the constant value(s) in your Configuration.h file of your Marlin version" And, how does one do that?
Weldon Thomson
CC BY-SA 4.0
2021-05-27T06:31:39.327Z
@WeldonThomson Download the firmware, get or configure it for your printer, compile the software and install this onto the printer controller board.
0scar
CC BY-SA 4.0
2019-03-19T05:12:03.537Z
2019-03-19T10:09:34.397Z
2019-03-19T10:09:34.397Z
0scar
<p>I have a new BLTouch that is setup (using Marlin 1.8.7) but I want to increase the probing grid from a 3x3 to something like a 5x5. I am using bilinear leveling with a 3x3 grid.</p>

<p>How would I go about changing that?</p>

<marlin><bed-leveling><z-probe><bltouch>
How to increase the amount of probing points for a BLTouch sensor in Marlin firmware?
Tanner D
# How to increase the amount of probing points for a BLTouch sensor in Marlin firmware?

(Asked by: username_0 on 2019-03-18)

I have a new BLTouch that is setup (using Marlin 1.8.7) but I want to increase the probing grid from a 3x3 to something like a 5x5. I am using bilinear leveling with a 3x3 grid.

How would I go about changing that?

**Tags:** marlin, bed-leveling, z-probe, bltouch


---

## 1 answers

### Answer by username_1 on 2019-03-19. Score: 13

You need to change the constant value(s) in your [Configuration.h](https://github.com/MarlinFirmware/Marlin/blob/1.1.x/Marlin/Configuration.h) file of your Marlin version from:

```

// Set the number of grid points per dimension.
  #define GRID_MAX_POINTS_X 3
  #define GRID_MAX_POINTS_Y GRID_MAX_POINTS_X

```

to:

```

// Set the number of grid points per dimension.
  #define GRID_MAX_POINTS_X 5
  #define GRID_MAX_POINTS_Y GRID_MAX_POINTS_X

```

This shows that to go from a 3x3 grid to a 5x5 grid you only need to change one value. Do note that you can set `GRID_MAX_POINTS_Y` to any value other than `GRID_MAX_POINTS_X`; replacing `GRID_MAX_POINTS_X` in the line with `GRID_MAX_POINTS_Y` to 4 would yield a 5x4 probe grid:

```

// Set the number of grid points per dimension.
  #define GRID_MAX_POINTS_X 5
  #define GRID_MAX_POINTS_Y 4

```

> **Comments:**
> **username_2**: "You need to change the constant value(s) in your Configuration.h file of your Marlin version" And, how does one do that?  
> **username_1**: @username_2 Download the firmware, get or configure it for your printer, compile the software and install this onto the printer controller board.  

---

