Post-cleaning of carbon rods and re-greasing lead screws, I started calibrating ELEGOO PETG Rapid and got a mess. I printed a few other items and all of them resembled the temp tower you see in this post.
What is going on here?
How do I fix this?
Printer: X1C
Slicer settings used: default for both Generic PETG HF and Bambu PETG HF.
That is indeed odd. It’s clearly a flow issue but whether its temp or extrusion is not clear from the just a photo.
This looks like the Orca temp tower. Just to be sure, after you click on the temp tower button, go up into the color scheme after you sliced it and select temperature. You’ll have to scroll down as it won’t immediately appear. If you’re not getting a gradient like this one below, hit CTRL-N for new project and start it over again. In case you weren’t aware, you can’t save the calibration file, or at least the last time I tested it, it erased the Gcode temperature variations, you have to start a new one at each session. So if you’re loading an saved file, it won’t work.
Thank you very much for taking the time to reply.
It is OrcaSlicer, as you surmised. Each time I redo a temp test, I go up to File->New Project. I do get the gradient you show when doing the temp tests.
I am concerned that I broke something when I cleaned the carbon rods and re-greased the lead screws.
One reason I think this is that, even though the printer was turned off for the carbon rod cleaning, as well as unplugged, when I would move the printhead, the light in the front housing assembly would flicker on and off. I am not sure how that could happen with the printer turned off and unplugged, but it did happen. I thought it was a spark or something, but it was pretty consistent when I moved the printhead at a certain speed.
Should I move on from the temperature test, keeping the testing temperature within the range for the PETG and move on to the flow rate test?
Secondly, should I be concerned that the printer continued to tell me that I need to grease the lead screws after I re-greased them?
Again, thank you for replying.
If that warning was triggered by resistance at the belt, it may be a false alarm—possibly a belt issue, not a lead screw problem. I mention this because although the warning is documented in the Wiki, you’re the first forum member I’ve seen report actually receiving it. I had assumed it was rare.
It wouldn’t be the first time debris ended up under the printer and damaged the belt.
The lead screws are driven by a belt located underneath the printer housing—a spot not typically checked during maintenance. Is there any chance something got lodged there? That’s where I’d look next. A faulty or obstructed belt could also explain the warning message that the lead screws needed greasing.
Before inspecting, be sure to tape the glass door shut to prevent it from swinging open, then flip the printer on its side for the best visibility.
For reference, here’s the Z-axis lead screw replacement procedure. You’re not replacing the screws, but the photos show clearly how the belt routes around the three Z-axis lead screws:
Did you try another filament? Also, did you actually dry the filament? I don’t mean tossing it in a dryer for a few hours—I mean weighing it, drying it, and weighing it again to confirm moisture loss.
Does this only happen with PETG, or do you see the same behavior with other filaments?
I was able to get the 0.4 mm nozzle to look better, but one side is terrible and it manifests itself in a model I printed from MakerWorld.
Once again, I am dumbfounded by a new problem: I use PVA for support for complex models, but I wanted to try it on a simple model. However, the PVA printed in the model at the levels of where it should be printing the supports. I have PVA marked as Support Interface and the PTEG labeled as Support Base. “Flush into objects’ infill” is also not active.
I have PETG-CF from a different manufacturer and it results in the same defects.
When I dry my filament, I do it usually at about 50-55 C for at least 8 hours…usually the filament is subjected to 2 or more dryings. I do weigh before and after, but I think my scale had too low of batteries when I weighed most recently; I put in new batteries yesterday and weighed some translucent filament, which had gained 120g in weight.
This ELEGOO PETG Rapid was weighed and dried approximately 2 weeks ago (lost 2g of water–but remember bad batteries) and I live in a desert with maximum humidity of 30% and usually in the low teens.
I cannot thank you enough for continuing to respond, as I am quite discouraged by my recent experiences and I do not think I will be able to get my project done on time. 
Don’t get discouraged—this is all part of the process. It’s completely normal to hit frustrating patches when things don’t come together right away, but once you figure it out, the sense of progress is well worth it. The key is to stay patient and methodical. I’ll offer a few suggestions here, though it may take another step or two before the root cause becomes clear.
Clearer photos would definitely help. The ones you posted are too small and blurry to see any useful detail. White objects are especially difficult to photograph, so this is a common issue. Try dimming the room lights to boost contrast. You might also get better results by holding your phone farther back and using digital zoom rather than shooting close up. Including something black in the frame—like a ruler or other dark object—can help the camera focus better and adds a useful sense of scale.
For what it’s worth, I’ve had good results using this approach even with a five-year-old base model Android. It’s more about technique than gear. The black ruler trick in particular helps a lot. Coincidentally, the example photo below, I printed last night using Elegoo Rapid PETG—the same filament you’re troubleshooting—so it should give a fair idea of what’s possible with a basic setup.
Click to zoom and open in a new window and click again to get full resolution.
Based on what you’ve done so far, have you tried a first-layer test? If not, it’s a fast and low-filament way to check filament flow.
No need to download anything—most first-layer test models online are overkill. Just right-click in the Prepare tab and insert a cube primitive. Disable “Uniform Scale” and set the dimensions to 200x200x0.20mm. This will produce a single filament layer over a wide area.
Objective: You’re looking for gaps, uneven flow, or irregular coverage in the printed sheet.
Click through the image gallery below for step by step.
Also—how did you clean the carbon rods and lubricate the Z-axis lead screws? Is there a chance lubricant got onto the carbon rods or X/Y belts? Check for any slick spots or discoloration by gently moving the toolhead with the power off.
If the single-layer test evaluates X/Y flow, this one checks vertical consistency using Spiral Vase mode.
Use a cube or cylinder primitive scaled to match the size of the object that’s giving you trouble. For example, if your temp tower is 10x45mm, set your model to 10x45x50mm.
Settings:
Brims ON – This helps anchor the object. Most slicers will do this automatically, but verify.
Spiral Vase mode ON – Accept the warning prompt; it will auto-set other parameters.
This will print a hollow object with a single-layer vertical wall.
Goal: Look for uniformity in the vertical wall. Any irregularities can point to extrusion or motion artifacts.
We’re looking for a test that consistently triggers the failure you’re seeing. Once you’ve nailed down a reproducible scenario, you can fine-tune variables quickly and with minimal filament waste.
Although it’s uncommon, it’s technically possible. When the printer is powered off and unplugged, manually moving the tool head can cause the stepper motors to act like small generators. Motors and generators are fundamentally the same device—coils of wire and magnets. In a motor, electricity moves the shaft; in a generator, moving the shaft produces electricity.
That said, I’ve never personally seen the front LED flicker under these conditions, but then again, you’d likely only notice it in a dark room. If the LED reached full brightness without you moving the head rapidly, that could suggest either stored charge elsewhere in the circuit or a lack of proper diode isolation. Normally, there should be components in place to block this kind of reverse current. Still, given Bambu’s tendency to optimize for cost, it’s not unthinkable they overlooked an edge case like this. However, this could be a diagnostic path you may want to pursue directly with Bambu if other troubleshooting measures don’t work.
@Olias Thank you very, very much. I shall test this later today.
Excellent ideas for taking the photos of my printed stuff.
The reason the images are so small is because I think someone would think it is obnoxious to have the images at their original size, which is usually somewhere around 30"x20", so I go into Photoshop and crop and reduce the image size down to 5" on the long side and whatever the aspect ratio results on the not-as-long side. I do not want to break any forum rules.
Again, thank you!
