Introduction: How to Resolve Z-axis Artifact / First Few Layers Blobbing Issue

3D Printing can be sometimes get very intolerable when you got stuck with some print quality issue and there is a wide range of factors contributing for the same problem, either you change your slicer settings or do some tweaking in you 3d printer. In this instructable I'll show how I troubleshooted my 3d Printer's Z-axis artifact.

Step 1: Knowing What You Have

So the first thing in troubleshooting is to have a knowledge about the printer you own. The first thing to keep in mind is that a 3d Printer is actually a combination of linear actuators. Now most of the problems that arises in a 3D printer are Linear guide related, linear bearing is broken, the belt is loose or too tight, or the belt teeth worn out, or your motor could be losing the steps and sometimes some issues arises due to very unstable printing settings. So for a successful print it is necessary to have a proper understanding of the slicer settings and of your 3d printer's capability.
Now here I have Kuongshun K10 3d Printer a chinese copy of Ender 3 and Geectech A10.
With Roller bearing Linear guide system.

Step 2: Analyzing the Problem

A While ago, I was Printing a few brackets for some project and I noticed this blobbing issue in the first few layers. Let me guide you through the steps I took to find out the problem.

0. Search the Internet :D

1.Bed Leveling
The first thing I re-calibrated the bed level yet no change in the blobbing occurred.

2.Infill Settings
I was printing with CUBIC Infill and at 80% infill density, they could have been the reason for this blobbing issue but it wasn't.

3. High Temperature issue
I was printing at a higher temperature for strength, Lowered it down nothing happened. Since I was printing in PLA so I wasn't using the heat bed, also turned on the bed in another trial yet no effect.

4. The Linear Guide
Now first I deduced that the problem was generated by the Z-axis Linear actuator.

Step 3: Blobbing Issue

One of the biggest issue with my 3d Printer is that I have Roller bearing Linear guide system. Unfortunately with only one bearing and I couldn't add more due the design of the roller that snap fits the bearing in its groove. So a While back I had another issue in the printing quality and I made changes in my printer, they didn't do much at that time but after a while those changes generated this blobbing issue.

I changed the stock coupler with a flexible Coupler. At that time the coupler didn't make any issue, but after a while the coupler deformed because the scrub screw of the flexible coupler got stuck into the grooves of the lead screw and whenever it moves up the coupler flexes and deformed the coupler a few milometers.

So, I replaced the Stock coupler back to its place and the blobbing was gone.

I hope this instructables would help a lot of other makers who are new to 3d printing, because the moment I got this issue I Searched the internet and all I found were a few other like me looking for an answer but no solution so here it is.