Reddit user hoges posted an interesting thread in the Ender 3 subreddit about a fix for an issue that he'd discovered in troubleshooting difficulties with bed leveling.

I discovered a couple of days ago that the eccentric nuts and the spacers which are used on the XY carriage are ~0.5mm different in height. That means that the carriage will be on an angle from the outset and need to be compensated with the springs.

This can lead to needing one spring fully compressed while on the other side the spring is at near max expansion and providing little stability.

Though 0.5mm doesn't sound like much, the difference is at the centre of the carriage so the effect of this is magnified towards the edges of the X-axis upwards of 5mm.

All this model consists of is a 0.5mm spacer that fits over the existing spacer on one side of the bed. I've tried to illustrate this in the attached photos, as some users requested photos of the procedure.

• In the first photo you can see that the spring on the left is almost completely maxed out in expansion while the spring on the right is fully compressed.
• In the second photo I have removed the heated bad and put it aside. The nuts with washers that you see, here, are your eccentric nuts that you adjust for the proper Y-axis movement of your bed.
• The third photo show things as they are out of the box. The distance between the carriage and the gantry being illustrated by the ruler.
• The next photo shows that same measurement from the other side of the carriage. Quite a difference!
• Next I removed the rollers from the left side of the bed.
• I've placed the spacers that I've printed over the metal spacers.
• The bearings are back in place and everything is tightened back up.
• And now we take our measurements, again, from the left...
• And now the right side. Almost perfect!
• As you can see in the final photo the springs are near equally compressed once the bed is leveled.

So there you have it. Such a simple little thing.

Now, of course, if you have a metal washer that is 0.5mm in thickness you can just use those. I didn't, so I whipped this little spacer up in Fusion360 and printed 2 of them.

Total printing time was about 8 minutes.