I am going to try to write down some of the more obscure issues I have had in the hope that it is beneficial to others. There have been many times when I spent far too much time diagnosing problems. As I have noted elsewhere, most if not every issue I have had has been as a result of “human error”… mine.
Sudden reduction in hot end repeatability.
Problem – In this case, I found that my prints were looking bad and I could not get the hot end to produce consistent parts. I noticed a slight noise change and could at times see the hot end vibrating a little.
Cause – A blade had been damaged on the part cooling fan. I believe it had happened when I was pulling the filament out some time earlier. The end of the filament went into the fan. At that time I did not think anything of it, and had forgotten about it. But now in hindsight, I recall it happening and it would be the logical cause of the damage fan blade.
Resolution – Install new fan.
Hot end thermistor reporting out of range.
Problem – Klipper suddenly shuts down reporting the hot end thermistor is out of range.
Cause – Thermistor wires were pinched and one broken inside the Stealthburner parts.
Resolution – Install new thermistor.
Super random layer shifts.
Problem – Layer shifting that was super inconsistent, slowly got worse and worse. Was not repeatable (i.e. happened at different points in the prints).
Cause – Seized (or seizing) Y-axis rail. The real cause was a poorly lubricated Y-axis rail car. Definitely my fault.
This was a painful lesson. It took me forever to even consider this would be the problem. So before determining it was the rail, I changed the MCU, stepper drivers, Raspberry Pi, stepper motors, wiring, and added more cooling to the stepper drivers. Lesson learned… take time to lubricate your rails properly.
Resolution – Replace all rails and lubricate them properly this time!
X-Axis end stop but the switch is still working.
Problem – The x-axis endstop stopped responding but an electrical meter confirmed the micro-switch was still operating.
Cause – Break in wire harness. That particular machine was using a premade wire harness that I had purchased. It had zap straps on it think I did not know to remove. The wire broke right at the zap strap which indicated to me that it was creating some stress and caused an early failure. This machine only had about 600 hours on it so it took me a while to even suspect the wire harness was an issue. But it was. I have had two other wire breaks in my wire harnesses since then. So… working my way to CANBus.
Resolution – Implement sensorless homing AND make a new wire harness. Both were much easier to do than I thought initially. Sensorless homing is awesome. And, making your own wire harness is probably a good idea if you are up to the challenge.
Belts shifted (slipping) behind StealthBurner.
Problem – I noticed my belts had shifted behind StealthBurner so I readjusted them and then marked their position with a maker. Sure enough they slipped again. And, again.
Cause – I believe I had two problems here. The first was over-tightening my belts. But even with less tension I still was experiencing some slippage. Eventually, I changed the back of my StealthBurner/Tap plate with a new print and in doing so I could see that the prior one had melted slightly (deformed). This I eventually learned was caused by heat creep which may or may not be specific to my configuration using Phaetus Dragon Hotend.
Resolution – I initially resolved this with the installaiton of a new printed back which clamps down the belts AND running the part cooling fan whenever the hotend and bed are heating. Since I am now pre-heating my printers for about 20 minites when they are starting cold. The PCF helps to create more airflow and reduce the creep.
Subsequently, I have also switched all my machines to CNC tap plates. This is a very good solution from my experience.
Stealthburner leaning forward.
Problem – I noticed StealthBurner was leaning forward slightly. This meant that the hot end was not perfectly perpendicular to the print surface. And, it seemed to manifest into reduced repeatability of the hot end.
Cause – This again seemed to be caused by heatcreep and as a result the stealthburner front screws sinking into the ABS StealthBurner front.
Resolution – Replace the StealthBurner front and run PCF whenever I am pre-heating and also cooling the machine.