3d Touch sensor : uneven auto level

mSteven
Posts: 2
Joined: Wed Mar 08, 2017 2:10 am

3d Touch sensor : uneven auto level

Post by mSteven » Thu Mar 09, 2017 3:27 am

Hi everyone,

I am getting strange auto bed leveling results, the leveling is uneven and it affects the print quality.

Here is an example :

I activated brimming for this print.
On the picture you can see 2 zones : A and B.
autolevel_err_reduced.jpg
autolevel_err_reduced.jpg (58.38 KiB) Viewed 10537 times
- On the A Zone, you can see that the brim width and thickness seems quietly correct : the nozzle was not too far and not to close to the bed when it as been printed.

- On the B Zone, you can see that the nozzle was really too close to the bed, it's really thinner than the brim on the Zone A, it looks more transparent.

The problem is always the same : the first layer on bottom left side is always (too much) thinner than on top right.

What does it imply ?

-> When I want to remove my part, the first layer always stays stuck to the bed in this area and the part eventually breaks there.
-> When I print large parts, the filament cannot be extruded properly and it sometimes clogs the nozzle.

I am actually using

Code: Select all

#define AUTO_BED_LEVELING_GRID_POINTS 2
Has anyone ever had this problem with the 3D touch sensor ?
Can anybody help on this ?


Thanks,
Steven

cosmith
Posts: 52
Joined: Mon Dec 12, 2016 8:58 pm

Re: 3d Touch sensor : uneven auto level

Post by cosmith » Thu Mar 09, 2017 7:05 pm

I have the same issue in the same area. I think it is a firmware problem. I've opened a dialog with the firmware creators to see what's going on.

mSteven
Posts: 2
Joined: Wed Mar 08, 2017 2:10 am

Re: 3d Touch sensor : uneven auto level

Post by mSteven » Sun Mar 12, 2017 11:38 pm

cosmith wrote:I have the same issue in the same area. I think it is a firmware problem. I've opened a dialog with the firmware creators to see what's going on.
Hi ! Did you get any reply from the firmware creators ?
How did you contact them ? Can you share a link of the discussion so I can follow it up as well ?

Cheers,
Steven

jchappo
Posts: 3
Joined: Thu Feb 02, 2017 6:49 am

Re: 3d Touch sensor : uneven auto level

Post by jchappo » Mon Mar 13, 2017 5:51 am

I have the same problem.
After performing a G28, G1 Z0, I carefully leveled the bed manually with feeler gauges to 0.2mm gap at each corner, and then rechecked after a further G28, G1 Z0.
I then performed a G28, G29, G1 Z0, and by issuing G1s to each bed corner I rechecked the gap and measured 0.2, 0.1, 0.05, 0.2 at the corners and 0.2 in the centre.
Is there a configuration setting to adjust the matrix algorithm?

cosmith
Posts: 52
Joined: Mon Dec 12, 2016 8:58 pm

Re: 3d Touch sensor : uneven auto level

Post by cosmith » Mon Mar 13, 2017 6:26 am

Here's the thread. They don't seem to think it's a firmware problem. I'm pretty sure it is.

https://github.com/MarlinFirmware/Marlin/issues/5977

--Colin

jchappo
Posts: 3
Joined: Thu Feb 02, 2017 6:49 am

Re: 3d Touch sensor : uneven auto level

Post by jchappo » Tue Mar 14, 2017 4:58 am

Thanks for the links - very interesting reading.
I am surprised that the bi-linear algorithm is not extrapolating to the un-probed areas. I think that maybe the linear option will be better.
Will run some tests today.

jchappo
Posts: 3
Joined: Thu Feb 02, 2017 6:49 am

Re: 3d Touch sensor : uneven auto level

Post by jchappo » Wed Mar 15, 2017 5:57 am

Made further tests.
Bed manually leveled with feeler gauges to 0.15mm.
After homing and running G29 (linear mode reading 4 points), Z0 now gives 0.25, 0.15, 0.1, 0.1 at the probe measured spots on the bed.
I think I will give this a rest until the firmware has been sorted. Reducing my active work table down to 185 x 150mm because of probing limitations is not worth it.
I will continue to use 3DTouch for Auto Home and not use G29.
My bed is level enough when done manually, but using the 3DTouch for homing lets me fine tune nozzle clearance by changing Z Offset on the LCD. I keep a chart of offsets/clearance values.

cosmith
Posts: 52
Joined: Mon Dec 12, 2016 8:58 pm

Re: 3d Touch sensor : uneven auto level

Post by cosmith » Wed Mar 15, 2017 8:31 pm

I agree with the above. It was working for me and now it's not. I'm getting much better results by not using the G29 leveling and just doing it manually. I'm not sure if it's firmware, hardware, or both. I just know I'm tired of messing with it.

arthak
Posts: 1
Joined: Tue Aug 08, 2017 6:33 pm

Re: 3d Touch sensor : uneven auto level

Post by arthak » Tue Aug 08, 2017 6:42 pm

I have the same problem here with the 3Dtouch sensor.

I have better results without this...

There is a way to fix this ?
Attachments
20747713_10155710527974430_1143206365_o.jpg
20747713_10155710527974430_1143206365_o.jpg (212.06 KiB) Viewed 9743 times

axenias
Posts: 7
Joined: Thu Nov 26, 2015 12:37 am

Re: 3d Touch sensor : uneven auto level

Post by axenias » Fri Oct 27, 2017 3:12 pm

Hello guys, another painfull story with a "piece of tech"... I am in the club also.

So i had a confilct with the Geetech guys about what is going on with this left side problem and voila we have an official answer. I hope this helps all of us:



Hello
Thank you for cantacting us.
1.Auto Bed Leveling has a limitation.The print platform must be flat. if it not, the auto bed leveling do not work. 3D touch uses the Hall sensor to generate magnetic force to control the 3d touch proble upper and lower. When the 3d touch probe is lowered, the 3d touch probe should be lower than the extrusion head in order not to affect the normal operation of the extrusion head (the die is 0.5mm higher than the hot bed and the hot bed does not interfere with the movement of the extrusion head) Height; after the probe is stowed, the height of the extruded head is lower than the height of the 3d touch probe.Therefore, 3d touch ,limit switch ,doesn't prevent the printing process.
About modify the parameters of Marlin for Auto Bed. You should modify these parameters in Configruation.h.To use normal leveling, we also need to accurately measure the following three parameters

#define X_PROBE_OFFSET_FROM_EXTRUDER 4

#define Y_PROBE_OFFSET_FROM_EXTRUDER -43

#define Z_PROBE_OFFSET_FROM_EXTRUDER -1.4

these are the offsets to the probe relative to the extruder tip(hotend-Probe)

//x and y offsets must be integers.

How to measure the offsets?

Before doing the measurement,you should change this parameter.

#define min_software_endstops true // If true, axis won't move to coordinates less than HOME_POS.

And the true need to be changed to false.Therefore, axis can move to coordinates less than HOME_POS.And you should make sure the steps_per_mm correct.

The steps:

1.Mark a reference point in the middle of the print platform.

2.Put down the probe, move the probe to the marker point and set it HOME manually.

The command:M280 P0 S10 //put down the probe

Through the manual operation of the host computer button, move the XY two axes so that the probe just came to the top of the mark, and then move the Z axis (the final stage as far as possible with 0.1mm button), so that the probe just hit the print platform

G-code:G92 X0 Y0 Z0

3.put up the probe, and move the X,Y and Z so that the distance between the nozzle and the platform can pass through an A4 sheet of paper.

4.enter the command: M114 And you can get the current coordinates.

Assume that the coordinates obtained are: OK C: X 4 Y:-43 Z:-1.4 E0.00

the offsets is 4 for X, -43 for y, -1.4 for Z.

After you change theses offsets in Config.h, you have to modify the parameter "#define min_software_endstops false" to "#define min_software_endstops true"

Then compile the Modified Marlin and upload the firmware to the 3D printer.

Therefore, 3d touch ,limit switch ,doesn't prevent the printing process.

About modify the parameters of Marlin for Auto Bed.

For you, you should modify these parameters in Configruation.h.

To use normal leveling, we also need to accurately measure the following three parameters

#define X_PROBE_OFFSET_FROM_EXTRUDER 4

#define Y_PROBE_OFFSET_FROM_EXTRUDER -43

#define Z_PROBE_OFFSET_FROM_EXTRUDER -1.4

these are the offsets to the probe relative to the extruder tip(hotend-Probe)

//x and y offsets must be integers.

How to measure the offsets?

Before doing the measurement,you should change this parameter.

#define min_software_endstops true // If true, axis won't move to coordinates less than HOME_POS.

And the true need to be changed to false.

Therefore, axis can move to coordinates less than HOME_POS.

And you should make sure the steps_per_mm correct.

The steps:

1.Mark a reference point in the middle of the print platform.

2.Put down the probe, move the probe to the marker point and set it HOME manually.

The command:M280 P0 S10 //put down the probe

Through the manual operation of the host computer button, move the XY two axes so that the probe just came to the top of the mark, and then move the Z axis (the final stage as far as possible with 0.1mm button), so that the probe just hit the print platform

G-code:G92 X0 Y0 Z0

3.put up the probe, and move the X,Y and Z so that the distance between the nozzle and the platform can pass through an A4 sheet of paper.

4.enter the command: M114 And you can get the current coordinates.

Assume that the coordinates obtained are: OK C: X 4 Y:-43 Z:-1.4 E0.00

the offsets is 4 for X, -43 for y, -1.4 for Z.

After you change theses offsets in Config.h, you have to modify the parameter "#define min_software_endstops false" to "#define min_software_endstops true"

Then compile the Modified Marlin and upload the firmware to the 3D printer.

Have a good day!




best regards

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