Bumpy y axis on Ender 3 V2

I purchased an Ender 3 V2 and began the assembly. I was following a Just Vlad video: Creality Ender 3 V2 - 3D Printer - Unbox & Setup - YouTube that seemed pretty comprehensive and added some initial quality checks on the base that I had not seen elsewhere. When I tested the bed movement, it hit two spots, almost like an indent catch. It was enough of a catch that i thought it reached its limit, but I knew i was well short of the total movement. I began fiddling with eccentric bearings under the bed as well as the belt. The belt did not seem quite straight, so I managed to sort that out. However, after fiddling for a while I have it improved significantly, but I still feel a slight bumpiness particularly at the most forward third of the movement. If I pull the bed to the front, then lift the front, the bed slowly glides to the back, so I think i have the right tension on the rollers. There is not wiggle to the bed either.

I was wondering if others experienced this and if there are some tricks to apply to get the last few minor bumps out of the travel. It is easiest to do this now before i put the z axis on the base.

Just a guess, but I had a belt being actually wasn’t straight when removed from the printer.


As you can see the belt is loose on the table and not straight. Every time when this section reached a pulley the axis stuttered and the caveat is that you cannot see such a fault when the belt is mounted.

Just a guess, but default printer belts are shit in most cases and replacing them using some fiber enhanced belts a not brainer anyway.

I agree. I would dismount the belts, lay them out, & inspect.

This makes some sense to me. I noticed a more significant improvement by getting better alignment of the belt. What would be a recommended replacement for better quality. It also seems like a spare part to have on hand.

Had a similar problem with a brand new Ender 3 v2.
In my case, it turned out that the eccentric nuts below the y-carriage needed adjusting.

There still is a slight bump, but I’ll see how that affects the prints before messing more.

@Pitan, I’m curious what this “bump” is. Can you describe it more, or post photos?

When I pushed the print platter back and forward, there were two points when the pressure felt different, as if a wheel was dropping into a dip, or low point - a bump ‘down’. (How do you describe a dip in horizontal movement?).

When first diagnosed, that happened when front and rear axels passed (more or less) the same point.

Following yesterday’s adjustments, the bump has reduced, and axels travel further before the second bump (about 10 or 12 mm).

No photos, because I can’t see what I’m feeling through my fingertips.

It sounds like you need to dismantle the printbed, remove the platter and inspect the rail system and V wheels.

Thanks @Ender5r , I did as you suggested, and found one wheel was far too tight - that is adjusted now, and feels much better.

@Pitan, it’s always good when you notice a problem then identify the cause, and then fix it.