Snapmaker J1 Linear Bearings Z-Binding Issues

Hi,

I´m having issues with Z-Binding on my printed parts (see pictures), where you can see obvious marks.
I bought the J1 on presale (NO Kickstarter) and got my machine in february, followed the Things to do first with a new J1 from Mechanikus and lubricated all Axis, but the error still persisted.
I guess that the z-axis linear bearings where not lubricated properly on my machine.

I got some minor improvments in print quality after Lubricating the Linear Z-Bearings with a 26G Syringe and NLGI class 2 grease and the clicking noises from bevor are nearly gone, when I move the Z-axis up and down.


Please ignore the weird Filament Blob, I accidently pressed on Pause Print.

The Lubrication process took me like 4 hours on several days, because it´s so hard to press the grease through those small nozzle diameter and with bigger sizes it was impossible to get past the sealing of the linear bearings.

My assumption is, that I need to add more grease, so the the ball bearings get better lubricated.
The question is, if it is easier to remove the linear bearings from the z-axis, lubricated them properly and putting everything back together, or I could continue lubricating with the syringe : _ (

I´m printing on different single extruder Printers since 2019, so I´m not a newbie :slight_smile:
I stopped using the printer, because I worry to damage the ball bearings inside.
I didn´t change much from the normal Cura Slicer Profile and the J1 seems to print fine except for the Z-Binding Issue.

My Printing Profile:
Printspeed (mm/s): Infill 250; OuterWall 50; InnerWall 90; Top 120; Travel 250
Acceleration(mm/s/s): Infill 6000; OuterWall 1000; InnerWall 1000; Top 3000; Travel 6000
Retraction: 0.8mm and 40mm/s

Any suggestions?

Here an Image after Lubrication. These are two separate printed parts in one job.

I tried printing with PETG as well, same result.

Here’s what i’m thinking: If you have the latest firmware I think we can rule out a badly tuned PID for the bedheating? To rule it out completely, you could set the bedtemp off/room temp and see if you get the same results. Maybe put masking tape if nessecary for bed adhesion…

Also, the position of motor/lead screw could be slightly misaligned…
Maybe try moving the bed slowly up/down manually with printer turned off and if the resistens is uneven, you could position the bed were there is more resistens and then loosen the for 4 screws next to the lead screw and then tighten them slightly. Maybe find another place were there is much resistens and repeat the process.
If this doesn’t solve it you could try doing the same thing but with the setscrew(s) on the coupler between the motorshaft and the leadscrew (if you can reach it). I do not envy your situation, Good luck!

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Yeah I´m pretty sure it is not the PID bedheating.

Nevertheless I will try your recommended methods this weekend.
Thanks for the reply :slight_smile:

No problem. I hope you find a solution to the problem. Just remember the motor acts like a generator when moved while printer is off. So dont move the bed too fast/with much force…

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Have you seen this one?

Maybe you could try doing the test that he does @ 5:05 in the video…

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I have played around with the screws a little bit.
Loosened them all and moved the bed manually up and down, while listening closely to the sounds.
I honestly can´t feel a big resistance, but I still hear some clicking sounds (probably from the ball bearings) especially when the bed moves down.

I´m still pretty sure, that the problem is with the lubrication of the ball bearings, but I´m no expert :slight_smile:
For a bed heating problem the artifacts are way to extreme and I can´t see a big bed temperature change on the screen.

Yea you are probably right. I have the clicking sound too :cry: but on my printer I can only hear it when the bed is moving up. Would be nice to get rid of it…

May be is the same part broken as on @i3sven 's printer. I mean there was a part from the bed broken from beginning

Do you talk about this post ? Help, terrible beating noise

In this post he had some problems with the X- and Y-gantry, or is there another post I don´t know about?

In my case it´s the Z-Axis and I don´t here any weird noises during printing (as I can tell).

this one…

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That was what I mean.

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You scared me into checking a bit closer on my z axis, so i cleaned off the old dirty grease and put on some new grease and the clicking sound is 100% gone :grinning:

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What clicking sound you mean? I have check it all too. Where was it from @RalosZk? I put grease on the z rails and the middle axis. I have hear no click if I move the Z. Is there some special that I have to wach.

You scared me buddy’s :see_no_evil::sweat_smile:

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When moving the bed all the way up in start of a print, I could hear a faint clicking noise but it got less and less with time and now that I cleaned and regreased the 2 smooth z-rods, the noise is gone.

If you regreased your z rods from the start and cant hear any clicking noise, I think you’re good =)

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Yeah I have grease them before the first print, and check all screws and stuff like that.

Don’t have the click😅 Hope it’s just the simple no grease issue on @RalosZk printer.

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If you don´t hear any noises when you move the Z-axis and you don´t have any weird artifacts on the print (like I do), then you´re fine.

In my case the problem is, that the linear bearings where probably not lubricated bevor assembly, so there is no grease inside the Bearings.
Lubricating the roads won´t and didn´t help (I tried it), because the Bearings have sealings to keep dust outside and the grease inside.
When you lubricate the rails, the sealing just pushes the grease up and down while moving.
Mechanikus explained everything in his thread Things to do first with a new J1

I´m waiting for my new syringe tips, so I can try again hitting the ball bearings with grease inside the linear bearings.

Perhaps I can make a small documentation, how I did it with the syringes. Usually you have to disassemble the Bearings from the road and lubricate everything, but I don´t want to mess around with the J1´s housing.

Holy moly.
This doesn´t match my kind of problems I guess :slight_smile:

I´m glad, that I didnt buy the machine as Kickstarter.

That will very helpful, I fight with the rails and the greasing problem too, can’t find syringe that matches. I don’t want damage the seal or something if I push them in the holes. Not easy to grease that machine

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How to lubricate your J1 linear bearings without disassembly:
-use small syringe (3ml) with luer lock system
-use NLGI class 2 grease
-use a straight 25G small syringe tip (24G is to big and 26G is always breaking)
-insert the needle between the rod and the sealing


-try to get as deep as possible into the bearings and push the grease inside
-you have to repeat this process from the top and from the bottom at several locations around the bearings, so you hit the ball bearings inside (I recommend every 60°)
-check if the noise is gone by moving the z-axis up and down. If not you have to put more grease inside the bearings (maybe at different locations).

You need a lot of force to get the grease inside. I recommend wearing gloves.
I used this equipment for it:
-syringe tips 25G:

-syringes:

-grease:

I will try do it again next week and I will response if it worked or not.
Again, this is not how you should typically lubricate your linear bearings :slight_smile:

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