<p>I have the following hardware configuration:</p>
<ol>
<li>Ender 3 Pro</li>
<li>SKR E3 Turbo</li>
<li>Ender Extender 400XL</li>
<li>BLTouch</li>
<li>BTT TFT35 E3 v3.0 (Marlin/LCD and BTT/BLTouch configured)</li>
<li>Dual Z steppers (per <a href="https://www.youtube.com/watch?v=6UgT9YqY3UA" rel="nofollow noreferrer">Teaching Tech</a>, example 3)</li>
<li>Dual linear rails on Y-axis (adapters by <a href="https://printermods.com/products/y-axis-linear-rail-adapters-ender-3-ender-5-cr-10" rel="nofollow noreferrer">printermods.com</a>)</li>
</ol>
<p>I plead guilty to having too many mods on this machine but everything was working until very recently.</p>
<p>After installing the linear rails mod, I discovered that the Y-axis movement was inverted in Marlin. I fixed that but (as of now) I can't get the device to home using sensorless homing (in Marlin mode on the TFT35) using <strong>Motion ▶ Auto Home</strong>. The gantry moves toward the (now disconnected) X-axis endstop switch (far left) and keeps buzzing until I press reset on TFT35 or cycle the power.  The Y-axis seems close to appropriate.  Marlin shows sensorless homing enabled/defined for the X and Y axes and the appropriate Diag pins are jumpered for the X and Y TMC2209s.</p>
<p>Additionally, the Z-axis seems to &quot;think&quot; the nozzle should be some 45 mm above the bed.  This being so far off, the BLTouch doesn't ever get triggered so as to define a soft endstop.</p>
<p>Specifically, executing a <code>G28 Z</code> results in an X and then Y gantry excursion to the apparent soft endstops, then to apparent X, Y - 0,0, then centering at X, Y - 200,200 (my bed is 400 x 400 mm).  The nozzle then raises to an indicated 0 (i.e., 200, 200, 0) which is approximately 40.1 mm above the bed.</p>
<p>At my age, I know I am at wit's end when I voluntarily go out and mow several acres of lawn in the oppressive Georgia August heat.</p>
<p>Sorry for the long, rambling soliloquy.  I would greatly appreciate any insight or other assistance anyone might offer.</p>

CC BY-SA 4.0
2021-08-07T23:43:13.750Z
What is the actual Z axis movements when a Z home is commanded? As in a rough estimate of distances and directions it moves.
Kezat
CC BY-SA 4.0
2021-08-08T00:01:27.390Z
I submitted a edited of your first paragraph for clarity, feel free to further edit or revert my changes.
Kezat
CC BY-SA 4.0
2021-08-08T12:39:46.760Z
Please see edits added in response to questions by kezat.
Hullian68
CC BY-SA 4.0
2021-08-08T19:08:19.380Z
To be clear. Sending a G28 **Z** command will cause all three axis's to move? Makes me think this is more then just trouble getting the thing to home. If you send **G92 X0Y0Z0E0** (to set all axis to zero) then try a independently move each axis such as **G1 X100**  will the single axis move alone and in the expected direction? For this test to prevent damage manually move the extruder a safe distance from the bed/endstops before attempting.
Kezat
CC BY-SA 4.0
2021-08-08T20:42:20.917Z
Sent M211 to disable soft endstops.  Manually moved nozzle to front, left corner and surface of the bed.  Sent G92 X0 Y0 Z0 E0 via Octoprint Terminal.  Manually (using TFT35 Marlin mode, move axis )  moved the extruder/nozzle to X 200.00, Y 200.00 and Z 200.00.   Then sent  (individually, from Octoprint Terminal) G1 X100, G1 Y100, and G1 Z100.  Results of individual G1 moves were:
Hullian68
CC BY-SA 4.0
2021-08-08T20:49:02.613Z
Overtime edit:  Sent M211 S0 to disable soft endstops.  Manually moved nozzle to front, left corner and surface of the bed.  Sent G92 X0 Y0 Z0 E0 via Octoprint Terminal.  Manually (using TFT35 Marlin mode, move axis )  moved the extruder/nozzle to X 200.00, Y 200.00 and Z 200.00.   Then sent  (individually, from Octoprint Terminal) G1 X100, G1 Y100, and G1 Z100.  Results of individual G1 moves were:  X100 -> 100mm move in negative (to the left) direction, Y100 -> 100mm move in the positive direction (i.e., bed slid forward) and Z100 -> 100mm move in negative (toward the bed) direction.
Hullian68
CC BY-SA 4.0
2021-08-08T21:03:26.943Z
So the conclusion of the test is X and Z are backwards and Y is ok? I would take a real close look at the motion system configuration. XYZ axis directions, homing directions, and if appropriate the normally open/normally closed setting of any endstops. To do a test print and test your settings (without fussing with homing XY) you can remove XY homing commands from your gcode and manually home the printer using the G923 command.
Kezat
CC BY-SA 4.0
2021-08-08T21:31:55.007Z
G923?  I don't see that on the marlinfw.org site.  Did you mean G92 and, if so, what would the arguments be?
Hullian68
CC BY-SA 4.0
2021-08-08T21:36:11.720Z
Yes sorry, not sure how the extra "3" snuck in. So the full command would be *G92 X0 Y0*
Kezat
CC BY-SA 4.0
2021-08-08T22:39:27.703Z
OK, had to turn off soft endstops (there are no physical endstops (TMC2209s and sensorless homing is selected)) , made adjustments on Y and Z inversion,  manually zeroed X, Y, and Z,  Sent G92 X0 Y0 Z0 and invoked a print of a simple thing.  Behavior of X and Y axis is as expected (good!).  Z stays way elevated and I suspect I have somehow neglected involving the BLtouch for getting the Z height correct.  Will be offline for perhaps an hour to prepare dinner, etc.
Hullian68
CC BY-SA 4.0
2021-08-08T23:13:00.130Z
Let us [continue this discussion in chat](https://chat.stackexchange.com/rooms/128364/discussion-between-kezat-and-hullian68).
Kezat
<homing><endstop><print-axis-offset>
Problem setting home and getting Ender 3 basic geometry dialed in
Hullian68
# Problem setting home and getting Ender 3 basic geometry dialed in

(Asked by: username_0 on 2021-08-07)

I have the following hardware configuration:

1. Ender 3 Pro
2. SKR E3 Turbo
3. Ender Extender 400XL
4. BLTouch
5. BTT TFT35 E3 v3.0 (Marlin/LCD and BTT/BLTouch configured)
6. Dual Z steppers (per [Teaching Tech](https://www.youtube.com/watch?v=6UgT9YqY3UA), example 3)
7. Dual linear rails on Y-axis (adapters by [printermods.com](https://printermods.com/products/y-axis-linear-rail-adapters-ender-3-ender-5-cr-10))

I plead guilty to having too many mods on this machine but everything was working until very recently.

After installing the linear rails mod, I discovered that the Y-axis movement was inverted in Marlin. I fixed that but (as of now) I can't get the device to home using sensorless homing (in Marlin mode on the TFT35) using **Motion ▶ Auto Home**. The gantry moves toward the (now disconnected) X-axis endstop switch (far left) and keeps buzzing until I press reset on TFT35 or cycle the power. The Y-axis seems close to appropriate. Marlin shows sensorless homing enabled/defined for the X and Y axes and the appropriate Diag pins are jumpered for the X and Y TMC2209s.

Additionally, the Z-axis seems to "think" the nozzle should be some 45 mm above the bed. This being so far off, the BLTouch doesn't ever get triggered so as to define a soft endstop.

Specifically, executing a `G28 Z` results in an X and then Y gantry excursion to the apparent soft endstops, then to apparent X, Y - 0,0, then centering at X, Y - 200,200 (my bed is 400 x 400 mm). The nozzle then raises to an indicated 0 (i.e., 200, 200, 0) which is approximately 40.1 mm above the bed.

At my age, I know I am at wit's end when I voluntarily go out and mow several acres of lawn in the oppressive Georgia August heat.

Sorry for the long, rambling soliloquy. I would greatly appreciate any insight or other assistance anyone might offer.

**Tags:** homing, endstop, print-axis-offset

> **Comments:**
> **username_1**: What is the actual Z axis movements when a Z home is commanded? As in a rough estimate of distances and directions it moves.  
> **username_1**: I submitted a edited of your first paragraph for clarity, feel free to further edit or revert my changes.  
> **username_0**: Please see edits added in response to questions by username_1.  
> **username_1**: To be clear. Sending a G28 **Z** command will cause all three axis's to move? Makes me think this is more then just trouble getting the thing to home. If you send **G92 X0Y0Z0E0** (to set all axis to zero) then try a independently move each axis such as **G1 X100**  will the single axis move alone and in the expected direction? For this test to prevent damage manually move the extruder a safe distance from the bed/endstops before attempting.  
> **username_0**: Sent M211 to disable soft endstops.  Manually moved nozzle to front, left corner and surface of the bed.  Sent G92 X0 Y0 Z0 E0 via Octoprint Terminal.  Manually (using TFT35 Marlin mode, move axis )  moved the extruder/nozzle to X 200.00, Y 200.00 and Z 200.00.   Then sent  (individually, from Octoprint Terminal) G1 X100, G1 Y100, and G1 Z100.  Results of individual G1 moves were:  
> **username_0**: Overtime edit:  Sent M211 S0 to disable soft endstops.  Manually moved nozzle to front, left corner and surface of the bed.  Sent G92 X0 Y0 Z0 E0 via Octoprint Terminal.  Manually (using TFT35 Marlin mode, move axis )  moved the extruder/nozzle to X 200.00, Y 200.00 and Z 200.00.   Then sent  (individually, from Octoprint Terminal) G1 X100, G1 Y100, and G1 Z100.  Results of individual G1 moves were:  X100 -> 100mm move in negative (to the left) direction, Y100 -> 100mm move in the positive direction (i.e., bed slid forward) and Z100 -> 100mm move in negative (toward the bed) direction.  
> **username_1**: So the conclusion of the test is X and Z are backwards and Y is ok? I would take a real close look at the motion system configuration. XYZ axis directions, homing directions, and if appropriate the normally open/normally closed setting of any endstops. To do a test print and test your settings (without fussing with homing XY) you can remove XY homing commands from your gcode and manually home the printer using the G923 command.  
> **username_0**: G923?  I don't see that on the marlinfw.org site.  Did you mean G92 and, if so, what would the arguments be?  
> **username_1**: Yes sorry, not sure how the extra "3" snuck in. So the full command would be *G92 X0 Y0*  
> **username_0**: OK, had to turn off soft endstops (there are no physical endstops (TMC2209s and sensorless homing is selected)) , made adjustments on Y and Z inversion,  manually zeroed X, Y, and Z,  Sent G92 X0 Y0 Z0 and invoked a print of a simple thing.  Behavior of X and Y axis is as expected (good!).  Z stays way elevated and I suspect I have somehow neglected involving the BLtouch for getting the Z height correct.  Will be offline for perhaps an hour to prepare dinner, etc.  
> **username_1**: Let us [continue this discussion in chat](https://chat.stackexchange.com/rooms/128364/discussion-between-username_1-and-username_0).  

---

## 0 answers

