Pressure based VS eddy NG type tap to zero

Sovol Zero
1

I’m going to spin this off of the existing thread

Sovol has changed their tap to zero method to no longer use the pressure sensor. In fact the latest printer.cfg doesn’t even define the pins for the pressure sensor.

The eddy is now defined as 2 different probes:

[probe_eddy_current eddy]
sensor_type: ldc1612
z_offset: 3.5
i2c_mcu: extruder_mcu
i2c_bus: i2c2
x_offset: -19.8
y_offset: -0.75
vir_contact_speed: 3.0

[z_offset_calibration]
non_contact_probe: probe_eddy_current eddy
contact_probe: probe_eddy_current eddy
center_xy_position: 96,76.2
endstop_xy_position: 96,76.2                        
z_hop: 5                       
z_hop_speed: 15
internal_endstop_offset: -0.20

Is this an IMPROVEMENT or are they hiding a hardware problem by turning off the pressure sensor?

2

This change also raises the question on how is the z offset intended to now be adjusted when necessary as it’s no longer a physical touch of the nozzle done automatically. That’s not documented anywhere, not even in the change notes. Is it z_offset under probe_eddy_current eddy that’s intended to be changed, or internal_endstop_offset under z_offset_calibration or something else?

Also what would be the correct method on getting it right, by feeling with a paper slip when Z is a 0 or something else?

Looking at the changes between firmware versions 1.3.8 (pressure sensors still used) and 1.4.2 (current latest), internal_endstop_offset was changed from -0.3 to -0.20 for some reason.

3

Are this changes arrived with OTA? Is there is a way to check what latest version available without running OTA update itself?
That is strange to turn off pressure sensor in updates.. it was designed to be there, and more sensor is better, i think~

4

Sovol’s marketing team agrees

image
image1920×1066 108 KB

5

This is the url the OTA update is using: https://www.comgrow.com/files/printer/ver.json

1 Like
6

Going to that URL right now shows the json file:

{
	"success": true,
	"title": "update",
	"rows": {
		"createTime": "2025-04-22 11:30:44",
		"customerType": "comgrow",
		"description": "test",
		"firmwareMD5": "397514d2331fa6a10939be33f5ecd021",
		"firmwareType": "comgrow_deb",
		"id": "08a91367-fd5b-4392-974a-aaa015421cee",
		"is_publish": true,
		"name": "comgrow_deb_test",
		"path": "https://www.comgrow.com/files/printer/SV08mini_Update_Package-04-22_1-4-2.deb",
		"versionCode": "1.4.2",
		"versionName": "1.4.2"
	}
}

Which shows version 1.4.2 is the version.

If you put the download URL in your browser address bar it will download the .deb file. Open that file with 7zip and you can “drill down” and see exactly what is inside.

7

You can also see the firmware version for the control screen.

8

Regarding the first layer height issues (I need to manually set the Z offset at the beginning of every print), could this recurring error have to do with the issue?

photo_2025-05-27_09-51-52
photo_2025-05-27_09-51-52866×639 47.8 KB

9

No, that an error of “start g-code” from Orca printer profile, that do small retraction of filament.
Somehow “newline” appears there in provided on usb files and produce error. Here is a fixed line:

G1 E-0.200 Z1 F600
2 Likes
10

Btw, i checked that OTA json, and its 1.4.7 already.. While i still on 1.3.7.
Is it ok to update? Does calibration without pressure sensor provide sufficient precision, and first layer same good as it was?
Or its better to wait some few more major updates?)

11

Fixed, thanks:

photo_2025-05-27_11-35-20
photo_2025-05-27_11-35-201110×895 123 KB

12

Thanks for that, I have been talking to Sovol about that same Command.

13

If 1.3.7 works for you then there’s no obvious benefit on upgrading to 1.4.x. As the saying goes, “if it ain’t broken, don’t fix it”. I’m still using 1.3.8 myself as the pressure sensor calibration has been consistent so far with various different filaments and temperatures.

I however don’t know exactly what the differences between 1.3.7 and 1.3.8 are as I don’t have the install package (or url) for 1.3.7 to compare with. 1.3.8 does at least installs a new klipper firmware and changes “axes_map: z,x,y” to “axes_map: x,z,y” under “lis2dw” in printer.cfg so it’s possible the axis mapping for the resonance tester has wrong axis order in 1.3.7 as lis2dw is the 3-axis accelerator chip being used by the tester.

14

The image file on the wiki for flashing to the EMMC is 1.3.7. I opened it with 7zip. I can upload a plain zip file if anyone wants.

15

I saw one youtuber complains about invalid resonator accelerometer orientation, which leads to unnecessary noise in calibration. Also min and max frequency was tight as [35,45] range, and he extends that to [20,100] to have better picture of resonance.
So that Sovol fixed axis in update its really good.
I could not say that currently i have ideal walls without echo, but it’s ok, so not major concert for update.

But my question about update was more subjective. How does it feels on fresh version, is it consistent? No sudden wish to rollback?