3 ways to add a dual Z axis - Including G34 auto Z levelling

by request three ways to add a second zed lead screw to your 3d printer including g34 auto zed leveling [Music] i had been considering making this video for a while so when it was requested by a patron it became a done deal plus i really wanted to try out g34 auto zed leveling in this guide we're going to cover three ways you can add a second z-axis lead screw to your 3d printer in this case an ender 3 but the concepts will apply to other printers and we're going to start with discussing why you might need this the majority of 3d printers move their z-axis with a lead screw and nut when it rotates the relevant part of the machine moves up or down many 3d printers such as the prusa mark iii have a lead screw on both sides of the gantry the ender 3 however only has it on a single side why does this matter well it means the gantry is more likely than not to tilt from one side down to the other i've rotated this image to be level and you can clearly see the gantry sags down lower on the right hand side a lot of the time there's no consequence for this and the fix is simply a matter of leveling the bed which will lower the bed on the same side and keep things parallel sometimes however it causes issues such as when i reviewed the ender 3v2 after removing the lead screws and dropping the gantry we can see that it gets really tight at the bottom and binds a little bit we can also see that twisting the lead screw lifts the left hand side but the right hand side is just rotating after some disassembly and a lot of adjustment i was able to get everything moving smoothly and that eliminated the binding and got rid of the artifacts in the prints but a better solution would be to support the gantry from both sides and we do that with a dual z-axis as mentioned we're going to cover three methods so here's a summary method one is purely mechanical no firmware no wiring no electronics and it involves having a bearing block supporting a second lead screw which is driven off a belt from the original one option two is to introduce a second stepper motor operated in parallel with the first we do need additional components but we don't need to touch the firmware option 3 is the most complicated but the most powerful to do it we need an upgraded main board and an abl system already in place but that gives us independent control of each z-axis lead screw and the ability to run g34 to automatically align both z-steppers and get the gantry perfectly parallel at the beginning of each print i recently saw this 3d printable kazoo on a prusa video and it's the perfect test print it's quite tall but doesn't take too long and the vertical walls will show up any artifacts from misalignment my filament of choice is this metallic steampunk rainbow available from x3d as we work through we're going to cover the pros and cons of each in more detail but no matter which one you choose your first step is going to be the same on the back of the machine smack bang in the place where we would add the lead screw is the power supply so we need to relocate it removing it is really quite straightforward there's just two bolts that go through the upright and into the side of the case technically you could just rest it on your bench to the side of the printer and call it done but for a tidier solution there's a range of printable relocation brackets on thingiverse so we're spoiled for choice when it comes to this part of the job which one you choose will depend on whether you have an ender 3 or an ender 3 pro because as you can see the power supplies have the same length and width but different thicknesses some of the mounting holes match such as the ones that attach to the printer but other ones are different i have an ender 3 pro which means the skinnier mean well so i went with this mount from jrpinter my advice if you print this is to add some manual support to the one area that needs it at the back of the case apart from that it's straightforward just a bit of a big print so will take a few hours once it's done it's a matter of removing the mounting hardware from the old case and if you need to taking a photo of any of the connections so you can reassemble within the new case correctly the same self-tapping screws hold the plug on the back and the original m4 bolts hold the case to the power supply in fact the only new fasteners you need are to mount the base of the case to the lower extrusion of the printer and that will give us plenty of mounting space for our three options with the power supply relocated we can move on to option one our concept here is to introduce a second lead screw and nut and drive it with a pulley and belt system from the original lead screw and stepper motor already on the printer many would consider this the simplest option because we don't need any wiring or firmware changes but the added components add a little bit of bulk to the top of the machine and they do need careful alignment for best results there's actually some mostly printable options for this on thingiverse such as this dual upgrade kit from scudi and the similar version from john at proper printing each of them has printable parts and lists other hardware that you'll need to buy instead i paid for an all-metal version which is a kit from th 3d that cost me 70 us dollars the reviews for this were great and it comes with some nicely illustrated step-by-step instructions on the th 3d support page unsurprisingly it comes with all of the components you need to add a belt driven second z lead screw all of the parts are metal and they're powder coated to match the original machine let's get on with installation and we're going to start by removing the three v rollers on the right hand side of the machine there's also two bolts that hold the v-roller bracket to the extrusion gantry that need to be removed as well what we're going to be doing is adding an additional bracket to the back of this assembly thanks to some spacers and some longer bolts apart from the longer bolts and the additional spacers assembly is exactly the same as before using the original v-roller wheels the instructions will tell you the correct order of the components with an m5 nut at the back in each case after we tighten the three v-roller stacks making sure that the wheels can still spin freely we can readjust the eccentric nut on this side to make sure that the carriage is rolling smoothly after this we can realign the gantry with the carriage and reinsert the fasteners that hold them together it's a good idea to make sure that nothing is binding before moving on we now introduce the new lead screw nut and use two m3 bolts to hold it on not too tight it's always good to have a little bit of lateral movement to take up any inaccuracy next up is actually removing the original zed lead screw because we're going to use it on the side that we've just added our new assembly to i added a fresh squeeze of synthetic grease and lowered the lead screw down into position on the right hand side of the printer with another dollop of synthetic grease the new lead screw that came in the kit then rotates down into place on the left hand side of the printer in place of the original lead screw and of course we insert it into the coupler and then tighten this we now have bearing blocks to introduce that go around the top of each lead screw we can secure them to the frame but only lightly for now once the lead screws are poking through we have a belt pulley that needs to go on flush with the top and then have the grub screws tightened but not so much it damages the lead screws following this we introduce the belt followed by the belt tensioner and if your filament spool holder is mounted on the top like mine you can position the tensioner to one side to make room now our installation is almost complete and we can see the new system in action now we have to get the alignment just right which is important for all of these methods but particularly for the first one as there's so many moving components if you're thinking you're going to skip this step here's why you shouldn't you'll notice here the z-axis is bound and it won't move any higher you can see in the test print it temporarily was stuck early on and then it completely bound up and failed the print alignment is important th 3d has a printable block for this of which you need two but with my printer modifications they weren't tall enough so instead i use these simple pieces of mdf cut to exactly the same length whatever you're using the idea is that you wedge it in between the frame and the underside of the gantry hopefully it's obvious that you need to make sure that it's sitting properly you can then introduce a block on the other side and as you can see my right side was quite a bit higher the recommended procedure is to loosen the two grub screws for the right hand pulley so the lead screw can spin freely within you can then manually twist the lead screw to lower or raise that side of the carriage until you get it flush with the top of the block mine didn't quite want to sit how i intended however so my solution was to loosen some of the bolts holding the gantry to the frame unplugging the z-stepper motor to protect the main board and then taking the carriage through its range of motion by hand to let everything settle before tightening up all of the fasteners again your aim is to have the two alignment blocks sitting flush against the bottom of the gantry on either side without the need to apply any pressure after plugging back in the z-stepper i started the test print and was delighted to find that this time it turned out flawlessly no binding and no vertical wall artifacts i'll say it again alignment is important cut corners here and you could end up with a printer that's worse than when you started that's method one complete so now let's move on to method two option two is to have a second stepper motor running our second lead screw except we're gonna run it from the same main board output which means we don't need to fiddle with the firmware this is still pretty simple to set up so the main downside is the additional electronics components that we need to source just like option 1 we still need a lid screw a nut and a bracket to hold it on the back of the machine but now we also require an additional stepper motor it doesn't need to match exactly as you might have guessed we also need a cable to plug it into the main board one last item we need is a coupler to go between the stepper motor and the lead screw th 3d stock stepper motors as well as a lead screw coupler and as for the loom i recently made a video showing you how to create your own with the proper crimping tools this method is compatible with all of the drop-in and the three replacement boards even though they only have four stepper motor drive outputs some of the newer boards already have parallel z outputs so it would just be a matter of plugging in the new stepper motor in the port next to the old one some other boards only have a single z output so with the help of a cheap adapter board we could plug this into the original z motor output and then our two stepper motors into the output of the adapter board one more thing we need is a mount for the stepper motor to the printer but this is an easy 3d print our first job in installation is to join the printed mount to the stepper motor and to do this we need a range of hardware some countersunk bolts and t-nuts to join everything to the frame and then some longer m3 bolts with washers to hold the stepper motor to the mount only loose for now we now take this sub-assembly and add it to the printer fitting the t-nuts through the upright extrusion and then tightening them we can see now that there's movement filled into this part which helps when aligning our lead screw add our stepper motor coupler to the output shaft of the stepper and now is a good time to plug the zipper motor into the main board as we showed earlier connecting it in parallel make sure the wires are clear of the moving bed it's actually okay to leave the belts in place if you like with this method but unfortunately for us the lead screw isn't long enough to reach so we need to lower it so that means removing the belt pulley from the top and lowering down the lead screw until it goes into the coupler where we can fasten it securely remember that our stepper motor mount is adjustable so move it until you find the best natural position and then fasten it in place our belt and pulley system from method one are no longer needed so we might as well remove them alignment for this method is the same as before just a little bit simpler because there's less moving parts we put our blocks in place and then manually turn the stepper motor couplers until the underside of the gantry is flush with our spacers on both sides start up the printer and check your wiring by doing some manual up and down movements of the z-axis after this you should be ready for another test print that's success with method two well almost because i did have one hiccup after introducing the second stepper i noticed that i had banding on some of my test prints as can be seen on the kazoo on the left this is a killer for print quality luckily the solution is simple rather than using a solid coupler like you see on the left i switched to a flexi coupler these allow a little tilt to account for inaccuracy but torsionally they're very strong so the stepper motors movements are translated to the gantry fortunately an easy fix it gave me smooth prints again so on to method three option three doesn't require to have anything additional added to the printer over option two which means we still need a lid screw a nut and a bracket to run it through and we also need a stepper motor a coupler and some wiring to the main board these all need to be installed the same as method two the downside is that we need our printer to already have an upgraded main board as well as an abl system so that means a main board with five stepper motor driver outputs and the one i'm using is the skr e3 turbo as it has five stepper outputs and bolts straight into the standard casing when you plug in your z-steppers into any of these boards the original z-stepper goes into the z-plug and the new z-stepper goes into the e1 plug leaving the extruder stepper plugged into its original e0 port all that's left is firmware and here's why we do it as an example my cr-10 max likes to go out of alignment when i feed filament if i'm in a hurry i'll just twist the lead screw to eyeball getting it even but the proper way to fix it is to use the leveling blocks as we've seen earlier in this video in return for needing to mess with the firmware we do get complete and automated control of the gantry being level the first thing to do is in configuration.h and that's to uncomment and set our stepper motor driver type to suit what we're running if you're running tmc drivers you might want to make sure that z1 and z2 have matching parameters in configuration underscore adv we then need to specify that we're running two z-stepper motor drivers and then find and uncomment z-stepper auto align after compiling and flashing the firmware we should find a new menu item inside the move menu we should be able to find and click auto set align and this is the same thing as sending the g code g34 let's have a look at the default behavior the process starts by homing the printer after doing this the probe will move over to the left hand side of the bed lower itself down very slowly and take a height reading the same way as it does when you're probing the whole bed for abl as we can see on the lcd it's telling us that it's doing g34 iteration one the probe will then move to the right hand side of the machine take a second reading display how far out the two readings are on the lcd make an adjustment and then begin the process again the default behavior is to do this five times or stop early if a specified tolerance is achieved at the conclusion of the final iteration the default behavior is to go to the center of the bed and homes at an additional time as the final step let's aggravate things a little more and repeat the process this time we're sending g34 via terminal for more information such as how far out each iteration was measured and the final accuracy reading in my case 0.03 millimeters the way i see it as g34 starts and ends by homing everything we can replace the g28 in our start g code with g34 to run the auto z leveling before every print after this g29 will run mesh bed leveling as usual that's the default behavior of g34 but what if we want to customize thanks to the testing of my patrons here's the options that we have the default behavior for g34 is to probe the bed as wide as the probe offset allows if you want to manually specify your points uncomment zstepper align xy and input a set of coordinates for each z stepper you're using this can also be input using the m442 g-code command let's say your angle was increasing rather than decreasing after probing one fix for this is uncommenting zed steppers orientation the default g34 behavior can take a little while to hone in on an accurate value so if we want this to be more aggressive we can increase the value for z stepper align amp however have this too high and it may overshoot and be unstable we can also increase the value for g34 max grade and this will allow us to probe with a gantry that's quite out of whack if you make this too high however you're likely to smash the carriage into the bed and have the probing fail if you're looking to speed up the whole g34 process we can either decrease the number of align iterations or increase the acceptable accuracy value to make it end sooner finally we have two options for what happens at the end of g34 i would suggest letting it home z again as we saw and i would also suggest running g29 after this process for the most accurate grid i'm happy with method 3 and i would like to employ it on some of my other printers that means all that's left for this video is to assemble and test out these [Music] kazoos [Music] i think we'll leave it there and if you have any feedback on my playing or this process please head down to the comments section 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: 72,679

Rating: 4.9444447 out of 5

Keywords: 3d printing, 3d printer, 3d print, 3d printed, dual z, z leadscrew, z lead screw, g34, auto z levelling, auto z leveling, kazoo, prusa, creality, ender 3, skr e3 turbo, firmware, marlin, th3d, upgrade, mod, modification, guide, how to, step by step, alignment, calibration, gantry, sag, tilted, gcode, m422, bind, binding, adjustment, kazoo kid, you on kazoo, test, demonstration, stepper motor, adaptor, stepper motor driver, tmc2209, psu, power supply, relocation, banding, coupler, flexible coupler

Id: 6UgT9YqY3UA

Length: 18min 50sec (1130 seconds)

Published: Fri Jun 04 2021