BLtouch for any 3D printer - Comprehensive step by step guide

bl touch this is your comprehensive guide to suit any 3d printer with a free step-by-step companion website [Music] i've made many bl touch guides before but always for specific printers and the trouble is they go out of date as marlin evolves so this guide is supported by a new page my free website which i can update in future to keep it accurate it also makes for a convenient way for you to follow along when you're updating things like firmware let's start by looking at what a bltouch is why you might want one and then work step by step through installation and setup this is a bl touch by ant clubs and it's an auto bed leveling sensor but what does that mean hopefully you know that a 3d printer's nozzle can move in a flat plane above the bed on the x and y axes so when we manually level the bed our job is to get it parallel to that plane what the bl touch does is probe a grid on the bed and at each location it's measuring the height and with that data it can build up a 3d map of the bed surface so instead of the user adjusting the bed to be parallel instead the movement of the printer will be altered to match the slope of the bed this is convenient but where abl really shines is when the bed is warped which no amount of manual leveling can fix again auto bed leveling will adjust the path of the first layer to make it ride the contours of the bed and that means on a warped bed which mine is and i can clearly demonstrate by the readout on the dull gauge i can achieve a perfect first layer even printing over the entire surface of the bed so what will this cost us a genuine vl touch will cost somewhere around 45 us dollars with the appropriate length extension cable this cable is required to connect the bl touch back to the main board with most printers needing at least one and a half meters in length you will find cheaper deals around but just pay attention to the length of the extension cable so you don't get caught out a quick note on clones like the thready touch now personally i've never used one but people seem to either swear by them or say they're rubbish i think they're probably both right and that means the quality is a little bit questionable so if you get one you could find yourself a bargain or you could find yourself in disaster and having to spend the money on a bl touch anyway the choice is yours let's assume you've got one of the other and proceed with the installation to install the bl touch you're going to need a physical mount there's a lot of printable mounts available on thingiverse and popular part cooling upgrade systems often have abl mounts as well these mounts typically work by attaching the bltouch to them and then attaching the mount to the 3d printer and our aim here is to attach it as securely as possible to ensure that the results are accurate as well as repeatable for this accuracy we also need to pay attention to the height the bltouch is mounted there's a lot happening in this diagram but it's pretty easy to miss this part here in red and it tells you that from the tip of the hot end to the tip of the bl touch you need a distance between 2.3 to 4.3 millimeters with the printer off manually lower the nozzle until it's just touching the bed a three millimeter allen key is in the middle of this distance range and you can see if it fits underneath if it doesn't you can adjust your bl touch up or down if the mount is an adjustable type if you're using a fixed mount and the bl touch is too high you can shim it downwards with washers but this is pretty fiddly and if your fixed mount positions will be a touch too low you're going to need to find and print a different mount you now need to run your extension wire from the bl touch back down to the main board and at the minimum you should be ensuring it can't snag on anything by cable tying it to the existing loom ideally you'll use some sort of sleeving or cable wrap to completely contain it and keep it safe at the other end we have the job of attaching our brtouch wiring to our main board and on my website i have a breakdown of what each of the five pins does and an example of a wiring diagram in summary red brown and yellow are used to control the bltouch with red and brown being 5 volt and ground and yellow being signal this signal is pulse width modulation and that basically involves switching a logic signal on and off and the ratio to which it's on and then off is called a duty cycle and for a vl touch different duty cycles indicate different commands most modern main boards have a dedicated port for these three pins here on an skr version 1.3 we can set their 5 volts ground and signal however when we line up the extension plug we can see the order is different on this creality board however everything matches and the plug could go straight in never assume the order of the pins is correct so always double check before you plug it in to avoid letting out the magic smoke the black and white wires are for the bl touch to communicate when it's triggered back to the main board just like the z-axis endstop we're replacing would when we're homing the printer because of this we can plug in the black and white wires into your existing z-end stop port pairing black with whatever is labeled ground some boards have a dedicated bltouch input for these this will work just the same but as you'll see later requires a bit more firmware alteration let's address some frequently asked questions such as do i need a pin 27 board some older main boards like the version 1 bots from creality had nowhere to plug in the bl touch but there was one spare pwm pin that went to the buzzer in the lcd the job of the pin 27 board was to plug in in the middle of the lcd and the main board hijacking pin 27 to stop the buzzer from working but making it available to control the bl touch any modern board however is going to have a dedicated bltouch or servo port spare and that means a pin 27 board will not be required what about if for whatever reason we can't use the inbuilt servo port how can we find out if any of the other spare pins are suitable we can look elsewhere on the board for spare pins an obvious place to look might be the max end stock pins and we can see from the diagram we have pin 128 and 126 we can google the chip used on the main board and then go inside the data sheet there'll be a section called pin description and then we come to pin 126 and we can see that it supports pwm whereas pin 128 is missing that from the description so pin 126 would be the winner for the yellow wire we're up to configuring the firmware and this is the scary part for a lot of people therefore i've embedded on the page my guide to setting up software and preparing a base violin configuration for your 3d printer no matter what your machine these following firmware changes must be done in configuration.h we need to uncomment define bl touch we need to uncomment auto bed levelling by linear and make sure it's the only one here uncommented and we need to search for and uncomment zed safe homing as well the next firmware change will be different depending on where you plugged in the black and white wires if you plugged in these wires to your existing zn stop which is my preferred method and the one i generally show in my wiring diagrams all you have to do is check that zmin probe uses zedmin enstock pin is uncommented and it should be by default if instead you've chosen to use some sort of dedicated bltouch port you need to uncomment zmin probe use this admin install pin uncomment use pro for z homing look up the name of the pin that you're using and put it after zedmin pro pin in this case for the creality board it's pb1 the following steps are optional but are highly recommended to have a dedicated menu for auto bed leveling uncomment define lcd bed leveling and for easy calibration later on uncomment baby step z probe offset and a probe offset wizard you can also input the x and y offset of your probe in the firmware but we can do this later on so i consider this step optional compile and flash your firmware to the main board and we're ready to calibrate calibration involves telling the firmware the exact position of the bl touch relative to the nozzle and i have a dedicated video to this which i've embedded in the page this video will take you through calculating your x and y offset different ways to measure it and how to format it and communicate it to the firmware it will also explain that z offset is the difference in height between the trigger point of the probe and the tip of the nozzle it will show you how to use the inbuilt marlon zed offset wizard to calculate this as well as later on when you're printing how to make fine adjustments on the fly everything should be ready to go so let's talk about the actual bltouch operation now when you home the machine x and y will home first followed by moving the probe to the center of the bed for the first time you're home it's best to use your hand to trigger the probe so if anything's wrong you have time to cut the power before a collision we are now ready to probe but before this we should bring the bed up to temperature so it can expand and take its final form now when we send a g29 i'll go to level bed from the lcd menu the printer will move the bl touch around the bed probing a three by three grid creating a mesh that can be used for first layer compensation now that we know where bltouch is working we actually have two options on how to use it when we're printing the first option is slow but is the most accurate and that is opt to have the bed probed after homing at the start of every print with the generated abl mesh immediately being used to compensate for the first layer to achieve this all we need to do is add g29 the line after g28 in the start g-code of our slicer some 3d printers however have a large bed and it takes a very long time to probe them so to speed things up you can bring the bed up to temperature then use the lcd to probe the bed and then immediately store the settings or send m 500 to save the mesh to the eeprom now in the start g code once again after g28 at m420s1 to restore the mesh and apply it to the following print before we finish this guide how about a little customization by default marlin will probe a 3x3 grid of the bed but if you have a larger format 3d printer you might want to increase the resolution this is really easy we just increase grid max points x to a larger number the probing speed of a bl touch with default settings is pretty slow but this is another thing we can easily change the firmware allows us to find a trade-off between speed and accuracy by changing both the xy speed in between probing points as well as vertical speed with homing feed rate z in this section you'll also find a way to enable multiple passes per probing point with the average value being taken to go towards the mesh you might notice from some of my footage that i've changed the position of the probing grid not only is it symmetrical rather than skewed to one side as is the default but i've also included a bit of margin at the front and back to keep well within the bounds of the bed this one's a little harder to find but in configuration advanced search for kinematic uncomment the four lines and specify exactly how far you want the probing grid from each side just make sure the margin you enter is larger than the probe offset or you could have the nasty situation where your probe misses the bed hopefully that's everything you need to get the most out of your bl touch in the case that you are experiencing problems i have a link to a dedicated bl touch troubleshooting page with common issues and their fixes remember that this video might become outdated in time but the website should be updated to stay accurate so use it as your primary resource if you found this guide helpful please let me know down below in the comments thank you so much for watching and until next time happy 3d printing g'day it's michael again if you like the video then please click like if you want to see more content like this in future click subscribe and make sure you click on the bell to receive every notification if you really want to support the channel and see exclusive content become a patron visit my patreon page see you next time

Channel: Teaching Tech

Views: 310,394

Keywords: 3d printing, 3d printer, 3d print, 3d printed, bltouch, bl touch, abl, auto bed levelling, auto bed leveling, guide, lesson, tutorial, step by step, beginner, how to, install, installation, firmware, marlin, wiring, faq, calibration, setup, offset, z offset, gcode, probe, grid, custom, customisation, configuration, antclabs, creality, ender 3, pin27, board, start gcode, slicer, changes, customise, customize, free, website, webpage, teaching tech, pwm, pulse width modulation, troubleshooting, issue, problem, homing

Id: eF060dBEnfs

Length: 12min 47sec (767 seconds)

Published: Fri Mar 26 2021