The saga continues. In the previous episode I covered how to stabilize your print bed. Determined in my quest to solve why Ender Alpha can’t print and then print again without adjustment I believe I have found the source of my problem. My gantry seems to sag a bit. For those unfamiliar, the gantry is the horizontal bar that holds the extruder and that the X axis rides on.
This fix will apply to any Cartesian printer.
On further investigation, I found that the lower wheel on the right side would spin freely.
This is the right-hand roller assembly
This is me turning the wheel freely. It does not make contact no matter what I do with the eccentric nut.
I could not tighten the eccentric nut and get that wheel to tighen. I know it was tight when I first put the printer together.
There are several solutions to this fix that often require taking the entire gantry off the printer. Being stubborn and determinedly efficient, I found a solution to the gantry sag that does not require disassembly.
Symptoms:
Printer requires readjustment after each print
Gantry is not level with the print surface or the top horizontal bar
Print is lop-sided
Without adjustment, prints won’t stick on right side or the hotend gouges print bed.
TOOLS YOU WILL NEED (Yup I said it.)
A level or digital level, I use a DXL360S – This allows you to verify the level of the print surface, the gantry and the top horizontal bar.
Your large wrench that came with your printer
Your 2.5mm allen wrench that came with your printer.
I RECOMMEND
DIFFICULTY: EASY
TIME TO FIX: 5 Minutes
The Plan: Loosen both eccentric nuts, the two screws on the right hand roller assembly. Align the wheels on the right hand side and tighten in reverse.
Here we go..
Loosen Eccentric nuts – An eccentric nut is a nut that is has an offset center causing it to tighten or loosen as you spin. You will see the roller disengage when you have it loose.
Left-hand eccentric nut
Right-hand eccentric nut
Loosen the screws that attach the right-hand roller assembly to the right-hand upright. Both are accessed from the backside.
This one is next to the power supply.
This one is more towards the center of the printer online with the gantry.
Now we turn the roller assembly to line up the rollers with the right-hand upright. In this case I rotated clock-wise.
Once the wheels are firmly against the v-track on the upright, I tighten the two screws and then the eccentric nuts.
Then I verify level starting with the printer surface (my desk), the top (horizontal bar) and the gantry.
On the printer surface
On the top bar
On the gantry itself.
These numbers can be off by a few hundredths.
Now level IAW the Makersteve steps and you are off and printing again.
And get back to printing!
Let me know if this helps or hurts!
There is a ton of other useful stuff on Makersteve.com and more coming every week.
Be sure to check out my Ultimate Build Guide for Creality Ender 3
If you find this useful, please consider purchasing products through any of the links on the page, it’s free to you and I get a little something for my time. Or, just go shopping at Amazon or Ebay or Gearbest.
You can also support me through Patreon with as little as a dollar a month.
Or buy me a Ko-fi!
Happy Printing,
Steve
Yep, I found this solution on my own a few months ago after much grief and tinkering.
The good news is that the correction is appearing to hold just fine!
but how does one adjust the top bar if its not as level as the other two. Also does the gantry have to be level on the y axis as well as the x axis.?
Top bar should be level as the uprights should be identical and a fixed squarely to the base. The y should be level but if it’s not you can account for it with the bed leveling springs.