i seem to be getting the above error, for all axis individually or home all. Try triggering the z ebdstop manually & see if it releases it may be stuck. the issue is that I can’t seem to get the head to retract far/fast enough from the bed post home. Currently when I home either X or Y the axis remains on the endstop. Facebook X (Twitter) Reddit Pinterest Tumblr Jan 17, 2022 · Endstop z still triggered after retract on SKR Mini E3 v3. But my homing retract distance is 5 and homing positive dir is true. 7. thanks for the reply. It is connected to dedicated port for proximity sensor given in BTT Octopus at 24V. The default of 5. printer. Maybe try add that? If you are new to reddit, please read the guidelines on reddiquette, self promotion, and spam. zamudio09. And with triggering z axes probe it didnt make homing for z axes. thanks for the tip, will do that when I get a chance. Start with X. It start working from setting sensitivity to 75 or less. The z-min is free and clear open. BTT Octopus 1. Inspect the endstop connectors for rust or dirt and clean. 3 KB. log file (use zip to compress it, if too big). Feb 12, 2023 · Feb 13, 2023. If I attempt to print before the steppers have disengaged, I'll get Aug 9, 2023 · Basic Information: Printer Model: Voron Tridex MCU / Printerboard: BTT Octopus V1. I have used a few different printer. klipper reads it as homed and I can move it. When ı want to home all axes it home first x and y (normally) but then the z axis sensor being triggered. If I trigger the endstop manually I get the Endstop x still triggered Ender 5 Pro, 4. klippy. 1 fluidd-config - v1. y_offset: 15. probe_with_touch_mode: True. 9:05 PM Endstop z still triggered after retract. You may be able to verify this by watching the homing action and seeing if the endstop remains triggered after homing, and Get the Reddit app Scan this QR code to download the app now. Sensorless homing should be enabled, homing directions are positive for X Y and Z. If I switch the reading with endstop_pin: ^!PA7, it considers the Z stop open and moves down, but doesn't stop when it hits the bottom of the Z axis and doesn't stop, starting to grind as it forces the motor. Im using and ender 3 pro with a creality V4. If The sign is not there, add it just before the pin name. Manually trigger an endstop and keep it triggered. Wires on bltouch on board are plugged in this order Dec 17, 2023 · First of all: Homing must work correctly. Where the V1 uses regular "^pin", the V2 uses "^!pin". The Klipper console is throwing "Endstop z still triggered after retract". Endstop Z Still Triggered after Retract . Endstop Z still triggered after retract. x board, you are fine. TL;DR. Endstop x still triggered after retract. Run m119 to get the status of the Endstop. Access your Sonicpad via the web. I'd like to move 5mm off the So I got the "virtual-klipper-printer" from mainsail-crew running with simulavr built separately. I then home all axis and I then get: Endstop z still triggered after retract. It'll give you an idea of what's going on. Remove the metal. This needs to work reliably for all endstops. Nintendo's Game Boy was dominating the market, but Sega entered with a portable, color, and backlit version of it's 8-bit home console, MasterSystem. Apr 27, 2020 · Roll back to your original Marlin 2. There will be a line which is showing a dir_pin, if there is an '!' before the pin name like this: dir_pin !PB6. Collaborator. Following up on this for posterity's sake, I still haven't pinpointed exactly why it's happening, but during some testing today I noticed that the bed moving beyond the half-way point causes the bed temperature reading to drop from 24C to -90C. Hello, i have uploaded marlin and everything works fine only the fwretract couldnt be changed :( the gaps are only at firmware retraction extruder retract and x/y is moving i tried it 100 times (real 100 times 😂) everything m502 m500 flashed it new nothing changed set everything to 0mm, test, set everything to 100mm, test, but it stays the same and i think the difference had to be visible Welcome to the Ender 3 community, a specialized subreddit for all users of the Ender 3 3D printer. Mar 13, 2023 · Here’s how to fix your 3D printer’s endstop when it stops working: Inspect and fix wired connections. View community ranking In the Top 50% of largest communities on Reddit. Basic Information: Printer Model: CR10S PRO V2 MCU / Printerboard: MANTA M5P + EBB36 CANBus Toolboard klippy (9). Hold down the x axis limit switch with your finger and QUERY_ENDSTOPS, x axis should read "triggered. Or check it out in the app stores Endstop z still triggered after retract General Question Hey Guys, This is the only thing I have left to do to get my printer fully operational. It seems to always think that it is at Z=0, and the levelling process does not work. 1 binary built for arm64, but I got it compiled with no errors. when I do a QUERY_ENDSTOPS, the x endstop always shows up as TRIGGERED no matter what. View community ranking In the Top 5% of largest communities on Reddit. It is # better to use the default than to specify this parameter. I have a weird issue. help with x max 3 hi for some reason im getting a endstop z still triggered after retract message i cant figure it out i did the latest firmware update and it started doing that pleaseeeee help me The question is when does it happen. Refresh status → Should read open again. The simulavr that is in the Docker container doesn't work, and there is no simulavr 1. This will reverse the direction of the stepper motor. log klippy. #3. Connect mechanical endstop to -X (left connecter where 1. What the error means is that, when homing, the toolhead (or bed) moved until it triggered one of the endstop switches. 0. Over 75 immediately triggered. 2 Kit. 1 with 2209 stepper drivers when homing it vibrates slightly (felt when touched) but doesn't go in any direction. After a print i After exchange the mother board it was not working - immediately triggered (X and Y). 9:05 PM Welcome to the Ender 3 community, a specialized subreddit for all users of the Ender 3 3D printer. #pin_up_reports_not_triggered: FALSE. It is possible that the endstop switch is stuck in the “on” position or that the printer carriage has shifted and is now too close to the endstop. 6 MB) Hi all, trying to setup my CR10S PRO V2 with an EBB36 board The X and Y home just fine, but when the Z axis attempts to home the probe deploys (BIQU Microprobe), the z-axis moves up slightly, and the probe retracts. Mar 16, 2020 · I did everything in the documentation. {“code”:”key23”,”msg”,”Endstop Z still triggered after retract”,”values”:[“z”]} I’ve been using the pin for the probe as PB1 but I don’t think that’s right since I moved the probe cable to the Z axis limit switch port. set_position Z is 0. X endstop triggered after retract is I’m extremely new to 3D printing. Endstop z still triggered after retract Btw, I use a BTT EBB Can 36, I already changed the wires, tried connecting it to the motherboard instead of the can. 33: 1294: Barkingmad15. It sounds like the X endstop if configured NO when it should be NC or vice-versa or the endstop pin is incorrectly configured. I got it to work on normal marlin firmware but id like to use it with my Sonic Pad. When I power on the printer, and hit FIRMWARE_RESTART in Mainsail, I'm able to upload a file and print. Use this command to get the current state of all endstops, useful for setup and troubleshooting. When homing X I get the message "Recv: !! First verify that the x limit switch is wired and configured correctly. ago. It's preferable to use the NC contacts. 0-0-gce48c585 klipper - v0. If your endstops read 'open' when the wire is disconnected it is a problem in the firmware or board. I currently own the Ender-3 V2 neo. But I stopped chasing a pack of gremlins and only ever chased one after spending weeks scratching my head. THE SWITCH ISN'T EVEN PLUGGED INTO THE BOARD FOR FECK'S SAKE. Can't copy and paste due to being on my phone. cfg configs and it doesn't seem to be changing. 1. The problem: Probe is still triggered after retraction. M119 Recv: x:open y:open z:TRIGGERED Result is okay. Get in touch with BIQU support through their website. I even tried two different endstop switches. Sort by: Garibon. 0 configuration if you messed with pins etc. The motor goes firm like it is going to move and has power but nothing actually moves. The printer doesn't have a screen , it's completely controlled by the sonic pad . Double check your wiring, make sure you don't have a loose cable. The QUERY_ENDSTOPS command should report the endstop as "TRIGGERED". 3. Hey everyone, I'm a noobie when it comes to klipper We would like to show you a description here but the site won’t allow us. Tried homing many times resulting in either it not homing in the right direction or bashing into the sensor and travel back in the wrong direction again. Troubleshooting Preformed: I replaced the endstop trigger. I have tried changing the variables and thresholds that determine the stallguard trigger, but was wondering if there were any other variables that might affect its reliability. I have a BTT SKR 2 with Marlin 2. And it won't 'home' because it thinks it already IS homed - because the z-min is TRIGGERED. (but still triggered) Oct 26, 2023 · 574×536 19. Shot in the dark but you might try setting homing_retract_distance in your stepper_x section. The Switchwire has the x endstop on the carriage, and homes by moving towards x max , to the right, So position of the x endstop will be the same as your max x size. Trigger manually then run the command again. Reply. Bed is then raised until nozzle touches. If I want a while, the steppers will disengage -- I don't recall what I have it set to, maybe 5 minutes. when I put a "!" It won't 'home. 0 is used if you do not specify it. Sometimes that’s correct but not always. I also noticed that when I home everything the z axis will go up about 10mm, home x and y, and then the z axis will go up another 10mm. Unfortunately the Ender 3 V2 Neo is pretty poorly documented and supported, so I'm using Ender 3 V2 config and trying to go from there. I haven’t tried it but don’t see why it wouldn’t work. Then I noticed on MainSail that the bed temp was reading 50C when the bed hasn't been heated (hotend is at 15C). 0-325-g99b97afc klippy (3). 9:05 PM _Home_Z_ XY Axis homed. This is also true for the Y axis but opposite. Update your firmware. Final setup . For TAP this isn't a problem and sensorless is fine. If the endstop does not change at all then it generally indicates that Thanks for your reply. So change the start code macro to home the axes individually, or all the ones you want before the move together, then do a move command, then home the remains axis or axes. *The only subreddit dedicated solely to the Game Gear!* Game Gear was Sega's entry into the handheld market. In my case the belt even starts skipping on X. So if you plugged this straight into a 4. I am having trouble with the bltouch when homing. I’m sure it’s in the firmware settings. and help would be greatly appreciated. log (60. y and z both work fine as expected. 9:05 PM _Home_Z_ moving to Z endstop position G0 X150. Repeat 3. • 4 mo. Creality CR10 and Ender3 (the only ones I've experience with) usually use 'normally open' switches which means it closes the circuit and sets a triggered state on the board. Try increasing (or adding) this value in your [stepper] config: homing_retract_dist: 10. Furthermore, BIQU tech support has been less than helpful, taking over a week to respond just to ask me to run the same test over and over again. I noticed when checking the endstops earlier they all were showing open, so I decided to go through each one to confirm each would show triggered when activated and noticed the z endstop isn’t working because it was unplugged when the bl touch was added. Anyone know how to set this up in Klipper? x_offset: 45. There is a feature in the stepper sections: #homing_positive_dir: # If true, homing will cause the stepper to move in a positive # direction (away from zero); if false, home towards zero. 3 KB) Welcome to the Ender 3 community, a specialized subreddit for all users of the Ender 3 3D printer. I have it wired according to rat os documentation which states blue/brown/black from top to bottom on the probe section. If the endstop appears inverted (it reports "open" when triggered and vice-versa) then add a "!" to the pin definition (for example, "endstop_pin: ^!PA2"), or remove the "!" if there is already one present. Feb 19, 2023 · Hold some metal against the probe. Endstop z still triggered after reset", if i try to run a print the machine tries to home in the z but cannot and has been crashing! I cannot level the machine either as it's alarming that the z is being triggered and cannot home, thus the machine won't go into the leveling mode. 9:05 PM _Home_Z_ Homing Z G28 Z. If for some reason the homing gets triggered to early, then you run the risk of the nozzle running into the bed when doing a z home. Move the x axis to the center of travel. If that doesn't work post back & we can see about further steps. Get the Reddit app Scan this QR code to download the app now. This subreddit has gone Restricted and reference-only as part of a mass protest against Reddit's recent API changes, which break third-party apps and moderation tools. fluidd - v1. 1 (F446) klippy. I am using the GT2560V3 control board with BigTreeTech TMC2209 drivers. I check z_enstop is triggering asgain using the "Endstops" in Mainsail and it is very inconsistant or very slow to trigger. Then hold one down and do it again. Inspect and Fix Wired Connections. i also perforemd the initial test from klipper website but it shows Probe triggered. log (181. 2 w/CR Touch and Microswiss DD -- "Endstop x still triggered after retract" I found another post with a configuration file for my same set up (Ender 5 w/CR Touch and Microswiss DD). For immediate help and problem solving, please join us at https://discourse. View community ranking See how large this community is compared to the rest of Reddit. txt (12. 2: 313: February 22, 2024 No trigger on x. LDO 0. Apr 9, 2024 · Hello together, im running a custom printer via Klipper on Android. Most likely the board. MCU / Printerboard: N32 Mainboard for Aquila X2, Aquila S2 3D printer. 2. Edit; After further investigation I've noticed that Moving x in positive direction yields the exact same movement as y in the negative direction. 9. Elegoo mod on reddit Reply Endstop x still triggered after retract. (And I am not lying when I say it's not the only thing that's f*ing triggered at this point. Remove diag jumps. M117 is typically because you don't have a [display] configured (?) and the M2xx would set acceleration which is hardcoded in the config and not adjustable through gcode, and M108 is marlin specific 'break' command. I will try and add the file with it. Nov 9, 2023 · Recv: x:open y:open z:open. 29. And give me trouble as shown in title "Endstop z still triggered after retract". The state of the Z probe and filament runout sensors are also reported with this command. Mar 8, 2023 · Can someone check out my cfg and log file, Trying to set up sensorless homing and have searched the forums for the last 3 days. 7. Here, enthusiasts, hobbyists, and professionals gather to discuss, troubleshoot, and explore everything related to 3D printing with the Ender 3. the triggered/open status is changing as expected. Replic8Gaming March 23, 2023, 12:24pm 3. it's a sensorless homing setup and I have jumpers over both the x and y diag pins. That can't be accurate - you'd be unable to move < 20 if there was an endstop there. I copied it in and modified it to Klipper's liking -- Klipper required a CANCEL_PRINT and VIRTUAL_SDCARD to be included which changed since the Apr 4, 2024 · Go to the Tune page and refresh endstops, then manually press the switch button and refresh with it pressed. jack-ster-1234. So here's the problem: The z-min is NOT triggered. config file and find the Z stepper motor which is turning the wrong way. 0-143-g01c7befa moonraker - v0. 1 Klicky Probe as Z endstop sesoreless homing for XY with TMC2209 drivers. r/BambuLab I reinstalled the factory firmware and the issue still persists, they all still show as triggered. Jan 16, 2024 · Auto E Stop for Z Endstop Switch & Sensorless homing users. General Discussion. When doing a first home after power cycling my 2. log (1. If I set deactivate_on_each_sample to true, get these errors less often, but the accuracy is worse, and that would also make creating a mesh much slower (the official manual sets it to “Please run ‘SDCARD_RESET_FILE’ or ‘FIRMWARE_RESTART’ to resume. Fill out above information and in all cases attach your klippy. I get a message of “Endstop z still triggered after retract” I’ve tried going through steps on this site (Connecting BL-Touch | klipper) but didnt work. It is mounted as per Voron Stealthburner guide. It then backed off 5mm (default), but the switch was still triggered after moving back that distance. Of course when I run home X/Y , since the printer “thinks” the X axis is already homed, it homes Y and Z correctly but the X axis stays in whatever position it might be at and never moves towards the end Reply. I'm trying to set up Klipper on my CoreXY Printer with TMC2130 on X, Y and Z. 12. 4 I get 9:05 PM Endstop z still triggered after retract. Pinda probe on z x reports “Endstop x still triggered after retract” issue G28 command for z and also get Endstop x still triggered after retract. Flash your own compiled firmware. When I QUERY_ENDSTOPS and QUERY_PROBE, as expected, it will appear as TRIGGERED. Aug 14, 2019 · Hywelmartin commented on Aug 15, 2019. That is certainly what is causing my reset, but I haven't pinpointed the "why". It finds X, Y home fine enough but once it goes for the Z it The small squarish endstop boards with a microswitch, as used on Ender 3 printers, is usually wired like that using the two outer pins of the 3-pin connector. 3 KB) Dec 1, 2022 · 3:58 PM Endstop z still triggered after retract 3:58 PM G28 Z 3:58 PM G28 X Y 3:58 PM Endstop z still triggered after retract 3:58 PM g28 3:58 PM Endstop z still triggered after retract 3:58 PM g28. any help would be much appreciated!! let me know if you need to me to share my config or anything. Open printer. Endstop z still triggered after retract - Klipper with ABL probe. I was able to resolve the issue by following the steps below. 6 KB) Aquila Chip: N32. I have no idea what it means or how to fix it. I have one of those cheap chinese capacitive z probes for ABL, I recently installed klipper on my ender 3 and octopi and had no issues until i tried homing. And this is important because of the [probe] pin: xxx config part. This may have already been resolved, but I am writing because I encountered the same problem. Swapped the endstop between X and Y axis; with the suspected "bad endstop" in the X axis, it was working fine, Y axis still has the same problem of constantly being triggered. 29 pin) and validate that M119 status for x_max is changed when you trigger it. Microprobe klipper issue Endstop z still triggered after retract each_sample: False x Unfortunately, after installing the V2 microprobe the problem still persists. It'll give you your current status for each endstop. No trigger on x after full movement. It will move to start homing and then probe wont deploy at all. The probe is working perfectly fine, I have checked it many Jan 8, 2024 · Basic Information: Printer Model: Aquila S3 by Voxelab. Aug 8, 2023 · Your X endstop is configured to be at position 20. log: klippy. Or you could just delete the entire block, but if sensorless homing doesn’t work reliably for you for some reason and you decide you want to go back to a physical endstop setup, you’ll be glad you didn’t delete it. I have an LDO Switchwire built and after assembly could not get the Z axis homing working properly. Endstop stuck at triggered or open. Lastly, and maybe this isn’t it. Endstops are reported as either “ open ” or “ TRIGGERED ”. But you declare ByVMType in the priority at the top of bootstrap but not VM-True. ) Jul 22, 2023 · Now, you have set some aliases for the BL Touch and you have a [probe] parameter, but the pin argument in it doesn’t match the pins in the alias statement. 1 MB) printer-cfg . Jul 29, 2020 · This seems like a legit bug, it was working and then it wasn't after an update. The exact wording is Endstop z still triggered after retract. Oct 9, 2018 · klippy. log Endstop x still triggered after retract That is the only thing I get. Mar 3, 2022 · It seems like the printer “assumes” that the X axis is at 0 when the printer powers on. I refreshed the endstops while lifting and then again when lower Tap/toolhead. cfg in "Configuration". If I set my probe to the config as V2, the printer will say "Endstop z still triggered after retract". log. puttin_in_w0rk February 21, 2023, 2:04am 9. " Verify that the x axis motor is wired to the right pins. 700 mm. 0 F6000. Checked the wires. 2. '. In both cases the print head moves along the x axis in positive direction. Remove the '!' sign. I have an skr pico I'm trying to get endstop functionality working on. Hold down the switch, click on the circling arrows to do another read, and see if it is recognized as being TRIGGERED. •. • 3 yr. Replace the endstop. Add "min_extrude_temp:0" to the bottom of [extruder]. com with the ZFS community as well. It probably is a sensorless homing. In either case, further investigation will be necessary to identify and resolve the underlying issue. 6 KB) Printer CFG: printer. I swapped out the block, put in a bi metal heat break, and changed out the thermistor. May 31, 2021 · Getting Klipper setup on Ender 3 with 4. Jan 12, 2024 · Thanks and going to start going through all the steps. Refresh status → Triggered one should show “triggered”. @NoGuru Printer config attached. Recently, I've had problems getting my endstop to work on the X-axis. 9 KB) After a longer break of arround 3 months, i recently plugged in my printer. Actual state Mar 22, 2023 · Refresh the endstop status in the webif → All should show open. Hi folks! I’d just bought a CR-30 and been trying to start it up, but every time I try to home the printer, it moves for half a second then stops and… BL touch is working fine BLtouch performs self test, reacts fine to commands like BLTOUCH_DEBUG COMMAND=pin_down and BLTOUCH_DEBUG COMMAND=pin_up but always shows triggered. If the status changes then this tells you the logic in the firmware is backwards. Attached is my printer config file. While up I see the red led light from the optical sensor on Tap indicating Tap properly powered and it turns off when Tap/toolhead is down. z motors dont move klippy(10). Does anyone know how to sort this issue out? On a bedflinger or core xy it doesn't matter if the nozzle is a little shifted horizontally, but when you have even a automated calibration routine like delta_calibrate where you determine the endstop position to one thousand of a millimeter and then you use a homing procedure thats as accurate as bumping into a endstop (which it is, but a View community ranking In the Top 5% of largest communities on Reddit my sensorless homing isn't working I have an Octopus v1. But I don't think I have any toolboard pins referenced in my printer config. Test your endstop for issues. . I have been pulling my hair out and searching for anything even close online for the last two days. I think when I first installed Klipper it required 'home all' before I could do anything else and once I got the X figured out then it failed on the Y and so on. log (129. I used the Sensorless Homing feature for X and Y before with Marlin and it worked alright. 51mm from the bed and the probe is at least 11mm away so it's way out of its triggering point. Oh, and all of this is on an Orange Pi 5 running Armbian, which works surprisingly well. QUERY_ENDSTOPS should read "open" for the x axis. I notice the fan on the left was briefly triggered when the home is pressed so I guess the x trigger was wired to power the fan somehow , I did some research online but couldn't find what this setup is this and how to config the printer properly at this point . Or check it out in the app stores Endstop x still triggered after retract upvote Jun 22, 2021 · Endstop z still triggered after retract" I’ve run the query endstop and it does show x, y are open and z is triggered. Don't go by color, go by pins. You should see it change from open to triggered. !! Endstop z still triggered after retract” Since then I have been completely unable to level the printer. The only thing I haven't done is a fresh install, but my understanding of git says that is not necessary. 8. 7 board and BLTouch 3. At the start of the print Mid print End of the print When sending movement commands at the printer without an active print I’m trying to add my anycubic mega x I compiled and everything works it heats bed and head, fans are good, x homes perfect then y… and the red header comes up endstop y still triggered after retract. As far as I can tell, there is nothing I can do to get the microprobe to read as “Open” as opposed to “Triggered”. The issue with this low setting sensitivity is that at such a low value is necessary higher force to trigger the endstop. This is the toolboard wiring from BTT. practicalzfs. Aug 22, 2022 · This last time that started today it is sticking. I am unable to print, I have this message popping up on my sonic pad, it says “endstop z still triggered after retract”. 1. If that doesn't work, posting at least part of your printer. Go into terminal through octoprint or pronterface or whatever you're using and type M119 and hit enter. 0 Y130. Also please post a resolution to your problem when you find one so that we know how to help others with your problem! I am a bot, and this action was performed automatically. But if you go by colors, which is the common advice, you are screwed. This is what my Z endstop/probe look like regardless of Tap position. If you have a [safe_z_home] section, you need to comment out the entire block (not just the [safe_z_home] line!). sensorless homing on x and y . cfg (1. Adjust the position of the endstop. 3 KB) Describe your issue: …I am using Omron Proximity Switch TL-Q5MC1-Z as my probe. Release endstop. Firstly, if a wire is broken, it will trigger as if the endstop was actuated, and be noticed by the firmware, which may or may not cause an alarm. The nozzle after retract is around 4. I queried the endstop in both states multiple times, all included in my klippy. Edit; Also Buzz Motors test correctly moves each stepper at the time. It's possible that in your setup requires a larger retract to clear the sensor. The sensor on the print head is still working. it was previously always triggered, but now it's always open, according to the M119 command, even if the switch is pressed. If the endstop appears inverted (it reports "open" when triggered and vice-versa) then add a "!" to the pin definition (for example, "endstop_pin: ^!ar3"), or remove the "!" if there is already one present. I’m not familiar with your main controller board, but I suspect that you’ve specified the Go to the printer. İt works at first but now it behave strange. It does appear to be triggering because the bed stops when it hits it, and its recognising that its still being pressed. Have tried. tried plugging in an actual switch on x and setting it up as a Jul 28, 2023 · The most likely cause of Endstop X still being triggered after retract is a mechanical issue. cfg (6. So I think it's some kind of configuration issue. On all z-motors and it still says the “Endstop z still triggered after retract”. Description. The # default is true if position_endstop is near Im trying to setup sensorless probing, i know its not recommended but after seeing a few people on youtube get it working properly i wanted to give it a go, since i dont have much options atm. Z Axis homing problem. Once you have that confirmed, release the switch, click on the circling arrows and see if it is noted as OPEN. Repeat for each endstop. They ended up sending me two more probes. i can use a different endstop plug for the physical switch at the bottom of my Z travel (in my case, thats Z_MAX) and have the DIAG pin setup in the The biggest reason is printers that run a z endstop switch at a specific location. Tedious, yes. These are all ignorable, or you can change your slicer config to not put them into the code. cfg could help narrow down the issue. je dg hm ag ch bq hl mc dj uz