Help installing Bl Touch on mongrel CR-10

  • Help.
    I have a CR-10 (I ordered the vanilla CR-10 but it arrived with a filament sensor so maybe it is an S??). Unfortunately the main-board suffered a fault a while back, and I had to replace it. I put in a Creality V2,2 board,, connected things up and away I went. All was fine.

    I recently thought I'd treat myself to an auto bed-leveller and the BL-Touch seemed to be the way to go.
    It arrived with instructions on fitting to the Creality V2 board and it looked straightforward. Essentially the Z-sensor connection was unplugged and the Touch connector (2 pin) replaced it. There was a further 3-pin connection which I connected as per instructions.
    When I powered on (after whipping off the z-sensor), I hit 'autohome' as instructed. The hotend moved, as usual, to the bottom left (0,0,0). It then set off diagonally across the bed before stopping and lowering towards the bed, with the BL-Touch dropping it's probe. The trouble is that it didn't stop, and went crashing into the bed. I tried again from a clean restart, with a finger on the power switch, and it crashed again.
    It occurs to me that the problem might be the mix of machine and main board. I tried the firmware for the plain Cr-10 and it bricked. I got it going again, via the arduino, and loaded the 10-S firmware, which works fine, but produces the above problem with BL-Touch.

    I hope someone can follow that rather rambling description and hopefully suggest a solution.

    Many thanks

  • Had same issues. Finally found this................saved me

  • @Bikerman 3DDesigners
    Nov 2, 2020

    Avoiding the many pitfalls when adding a BL Touch V3.1 to your CR10S with V2.1 mainboard.

    Frankly, if you think this BLTouch addition will be an easy improvement, think again. Be prepared for confusing instructions, missing and incorrect information, dead website links and no technical support (not from Creality support), above all a lot of frustration and this is definitely not a Plug and Play device by any means.

    I bought a genuine BLT from Creality being very careful to select the correct version suited to my machine, this despite the confusing BLT versions shown on their website, namely the option for CR10S V2/3 alongside a version for CR/Ender Series. When Creality use V2/3 are they talking about the Printer version or the Mainboard? I guessed they were talking about the printer version, but it is not clear and unless you have taken the lid off your control box prior to ordering, you would be none the wiser. Anyhow what arrived was for a Creality V1 board with both the instructions and the parts, and mine is a 2.1 board. To fit this to a V2.1 board It turns out you do not need the enclosed "Pinboard A", "Burner" or "ISP Pinboard" or the instructions, apart from that you have everything you need!

    Now, I have every respect for the Chinese presenters on the Creality YouTube channel (speaking English), but when it comes to physically connecting the BL Touch to the mainboard the video offered is sadly lacking. The presenter actually shows the differences between the V1 and V2 series of boards and roughly where to place the two connectors on the board, but suggests you look at other, non- Creality, YouTube videos if you want to know exact details. Of course, I want to know exact details! because if you don’t get it right you are in for hours of frustration. There is a block of connection pins set out in a four by three grid on the mainboard and without the exact positioning detail, by my calculation you can connect the 3-pin connector in one of 8 positions! (4 positions within the connector one way round and four with the plug reversed). I ended up going through them all, just about.

    Okay, having spent the first paragraphs moaning about things I’ll skip all that (It needs addressing Creality!), and explain how I eventually solved the installation and got the thing working. I hope it helps anyone contemplating adding one to their machine and avoids 16 hours of frustration.

    CR10S (machine version 1), with a V2.1 mainboard and a BL touch version 3.1 supplied, Cura software.

    1. Update the Firmware. Don’t get dragged into Bootloaders, Burners, Baud Rates and Binary files or modifying G codes, just get a USB lead that has a plug one end to fit the printer control box (USB B mini) and your computer at the other (USB A). Disconnect the control box from the mains (240 ac) then plug in the USB lead both ends thereby connecting the computer to the box. The Control Box LCD will light up and display the usual menu (receiving power from your computer).

    You need to then download a copy of the new Firmware which incorporates the addition of the BL touch code. Go to the Creality website:


    You will need to “unzip” it and save the extracted file somewhere on your computer, use the “desktop” location if that is easiest.

    This is a .HEX file.

    In Cura go to "Settings", "Printer", " Manage Printers". Select Creality CR-10S and Update Firmware. Cura handles all the connection protocols, although you might need to wait a few seconds for it to connect. Click on the Upload custom Firmware button. Navigate to the .HEX file (on your desktop if that is where you saved it) and upload, easy. Wait until it is finished. Then still in Cura and while still in the “Manage Printers” section go to the button that says “Machine Settings” and click on it. The window shows the printer settings and at the lower left “Start G-Code" scroll down the code until you reach the first of the G codes.

    I.e. after M221 S100 ;Reset Flowrate and between G9 2E0 ;Reset Extruder

    Insert the following code

    G28 X0 Y0

    G29 Z0 ;Home

    Note: there will be a G28;Home there before you start inserting, just modify it.

    This bit of code will now precede any model sliced in Cura.

    You are now committed to the install! Disconnect the USB lead.

    1. Mechanical Install of BL Touch. For this bit you can actually use the supplied instructions. The version of the BL Touch and the mini connector are both on the same side of the device. Before you attach it to your machine just jot down which version you have from the label and secure the 5 pin (5wire) connector to it because once you have fixed it to your machine you can't do either. At this stage you can also remove the “Z” stop connector from its socket followed by removal of the Micro Switch assembly bracket (3 Screws) from the printer. Ie the original method of stopping the machine at Z zero

    2. Connecting it up. Hopefully you have the mains electric disconnected still, if not do so. Turn the control box over (upside down) and remove 5 screws from the base plate, ensuring you keep them safe, to expose the Power supply unit. This is held in by 4 screws on the side of the box, remove them and put these to one side. You now have to remove the Power Supply box from the main box to expose the Main board, you do not need to remove any connectors or wires. Balance the Power Supply on some books next to the Control Box so as not to have it dangling and straining the wires.

    Next look at this. Printer/Creality/BLTouch Guide book for Creality V2.1 mainboard.pdf

    (Try finding this on the Creality Site ! This being the most important document you need. The QR code just takes you to the front page of their website)

    Anyhow, look at the picture and identify, before you connect anything, where the connector wires go.

    Feed the wires from the BL touch into the case through the rubber grommet at the back of the machine. If you prize it to one side you can get the two connectors through with relative ease.

    Connect the Yellow Blue Red connector to the correct row of pins (as show above Link) ensuring it is the correct way round. Must be as image shows.

    You will be left with the Black and White wired connector. This goes in the Z end stop socket and to do this you need to remove the, now redundant Z limit plug and place the BL Touch in the same hole.

    At this point you can double check the connections are secure, the right way round and to the correct set of pins.

    Put the Power Supply back in the main box with the screws then do the same with the base plate.

    IMPORTANT: The black and white (Z socket) connector has to be connected the right way round and, in my case, I had to swap the black and white wires around by removing the delicate pins from the plug and swapping them over. You will only know if this need doing when you fire it up for the first time. i.e., when the print head crashes into the table. Hopefully yours is correct.

    Nearly there (famous last words).

    1. Commissioning. Re-connect the mains power supply and turn on your machine. First thing you will notice is the LCD displays a slightly different menu. If all is working and your Z height is not too close to the bed the BL Touch will go through a routine where the probe part operates 3 times, 2 quickly and the third a bit of a delay. So far so good.

    Now, the easiest way to do the next bit, setting the Z offset, is to follow the method shown on the instructions. "Auto Home" first from "Prepare" menu, hopefully the printhead behaves itself and doesn't crash (see note below about reversing Black and White wires if it does) .What this offset process is doing is setting the difference between the nozzle tip and the BL touch trigger point. Make sure you do the A plus B calculation right, the -/+ can get confusing when you are adding two numbers together. C should be around –2.1/-2.8.

    Make sure you “Store Settings” once you have set the offset.

    I think you are done!

    Do a “BL Touch test”, which you can do from the control box menu, and then a “bed level” when your machine will probe the surface 9 times.

    Do a test print from your SD card sliced and saved in Cura so that it has the extra Gcode at the start.

    If the print head crashes, check the offset again as this is the most likely cause, if the head was going to crash you would have found out by now when carrying out the "Auto Home" instruction. if not you probably need to reverse the black and white (Z) wires. (pain in the backside)

    This is a long document, but I hope it makes the installation clearer and avoids you having to spend the hours researching fixes as I did. Is the BL touch worth it? Without a doubt. One day there will be a Plug and Play version, I hope.

    Oh.... Remember to do an auto-home before printing to establish the X Y Z start positions

  • Sorry nobody has replied to you yet.

    Think you are going to need to go to the Marlin site and compile firmware yourself. There are plenty of settings in there that might suggest what is wrong.
    Also - check the Marlin website - there are plenty of instructions on manually sending gcode via usb that can help you troubleshoot.

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