Thanks for your input Jeff
I’ll give your suggestions a try, and let you know how I go.
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Again not trying to derail the conversation here but…
If your model was not supplied with a top bearing mount for the z-axis screw, go to Thingiverse and print one. It probably has no direct effect on your current problem, but if the screw is not aligned properly strange things can happen as the print height changes.
I wish I’d seen this comment when setting up my printer, My Z screw wobbles around, so this may help. I may have to do this as part of the little refresh I’m doing on my printer to get it feeling up to printing the ABS parts for my next printer.
Thanks for the tip! That’s the great thing about the Enders, because tons of people own them, there’s a ton of easy upgrades around.
-James
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I agree James, Jeff’s suggestion makes a lot of sense. Please let me know if you find a good example of a top bearing mount for the z-axis screw - I had a look around Thingiverse but was unable to find what I thought would be suitable…
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Hey all,
Re: the top bearing mount, there has been lots of discussion as to whether or not its a good idea to fasten it. Personally, I would leave it loose or unconstrained, fastening that at a fixed distance can warp the leadscrew if not perfectly aligned is and make more issues down the line: https://www.reddit.com/r/3Dprinting/comments/a3cfsi/is_it_normal_that_this_bearing_on_top_of_the_z/
I definitlely agree that something has to be done about the small offset between the motors drive axis and the X-axis carriage lead-screw nut. Something like this usually gets the job done: Ender-3 Z-motor spacer / support by Supavitax - Thingiverse
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Hey Geoff,
Based on your previous topics it might even be worth measuring the aluminum extrusion on the X-axis, I have heard that a couple holes have been wrong on some batches, I’ll bust out my calipers and measure up my printers. The measurements we’ll be after is the total length and the distance to each of the mounting holes, any variation will compound to the point where it may not grip like in this instance!
EDIT: On the right hand side 9, 66,89mm, left hand side 5, 29,58 with a total length of around 340mm
EDIT2: The Ender 3 Pro has the same dimensions from what I measured
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This is great, thanks Liam
I’ll do some measurements and let you know how mine compare to yours.
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Hi all
This might be the topic of a separate post, but I’ll continue here since it’s all Ender 3 V2 related…
I’ve had some success in being able to tighten the concentric nut / rollers on the right hand side of the X-bar (last night) - not perfect, but certainly reduced the apparent problem. With a little less up-down movement on the right hand side - I’m still going to review all of the valuable tips offered on this topic - I started some test prints, e.g. bed levelling prints. I found the results were good initially. Then, within a few further prints, the filament wasn’t sticking because the z-offset seemed to have increased of it’s own accord. This is indicative of my recent previous experience, that I take a lot of care initially levelling / tramming, and get a great result initially. Is there any merit in considering whether my z-end-stop-switch may be malfunctioning in any way? The switch ‘clicks’ as I expect, and seems to operate well, but do these have a habit of being inaccurate?? I’m trying to brainstorm all of the different things that might be leading to my inconsistent printing results. I do feel I have a good grasp of bed levelling/tramming as I get initial prints that are good (over the bed as whole), but then things seems to ‘change’ very quickly…
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The suggestions offered for this issue are usually incorrect. As supplied, the unit will likely be assembled with an offset, but that is because of the assembly, not the components. I can’t recall which way around it is, but if the motor is already attached to the bracket then removing the bracket from the motor before attaching it to the frame, then re-attaching the motor to the bracket, fixes the problem. Or the other way around.
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I may have misunderstood your problem. I though that the x-axis bar was shifting away from being parallel to the build plate as the build progressed. But it seems that the problem is that the x axis bar does not remain parallel to the build plate between builds. The most likely reason for this is that the build plate position is disturbed while removing the model, and this is turn is likely due to having the build plate level at a point where the springs under the screws are not adequately tensioned. With loose springs the plate can sit at different heights. To fix that you need to level the build plate, then screw all the springs down, making the same adjustment at each corner, until one of them has become almost fully compressed. Then adjust the z-axis stop to get the height approximately right (a bit high). Then level the build plate as per normal.
Of course, the z-axis guides on both sides should be firm against the uprights, so that is worth addressing, but if the problem is that you are losing your level, then the build plate is the more likely cause.
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Thanks Jeff. I did buy some better springs recently (recommended upgrade to the standard springs), but I will double check to see if I can comfortably get a little more compression to ensure the build plate is not being disturbed between builds.
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Just wanted to provide an update on this post - thanks for all the support!
- I identified a 1.5mm difference in the distance between the left and right uprights at the top, versus at the bottom. At the top the width was 251.0mm, and at the bottom it was 249.5mm. See image below for the reason - poor assembly by me in the first place! I just needed to undo the nuts at the bottom, then re-tighten them and they held the new (flush) position nicely. This allowed me to then have more tension in the rollers in the right hand side of the X-bar.
A second major breakthrough for me was actually identifying some ‘play’ in the Z-end-stop-switch black plastic housing - see image below. This was actually enough to create a difference in bed levelling from one print to the next, of 1 paper width to 4 paper widths! I’m guessing the method I used fix this is probably not recommended(!), but I gave it a go and it’s worked for me. I added the smallest drop of thin CA to hold the black plastic in place - not a great idea if I ever want to pull the switch apart in future.
I’ve also added a link to a video of this: Z end stop switch movement - YouTube
Thirdly, I identified a slight dip in the middle of my glass bed - per another Youtube video, I used some lines of tape below the glass bed to help fill this small dip.
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That’s a good catch - thanks for the heads-up. I have been through my stock of limit switches, of several different styles, and I can’t see one that shows the same movement, so it seems to be an unusual manufacturing mistake.
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I was very happy to pick it up - I knew there was something very wrong in that I needed to re-level the bed for nearly every new print! I couldn’t believe that such a small amount of movement/slackness in the switch resulted in such a massive difference in distance between nozzle and build plate (in terms of paper thicknesses).
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