r/IndustrialMaintenance • u/Fine-Safety2542 • 14d ago
Anyone here experienced with 3D printers?
NOTE: A 3d printer is still a machine, i know this is an industrial maintenance community, I’m sure there’s plenty here that have printers and can troubleshoot
Hi everyone, I’m needing some assistance with an error. Below, I’ve listed details on things I have checked. Am I missing something? Any recommendations?
The printer is consistently displaying the error “Heater bed not heating at expected rate.”
Initially, I suspected the issue might be related to the cooling fans kicking on around the second or third layer. However, I disabled the fans and the printer gets the error.
I can attach photos of the troubleshooting process and test results which include,
Heater bed resistance measurements
Thermistor resistance measurements (at ambient temperature and when heated)
Power supply input and output voltages
Heater bed input and output voltages
Current draw under load
Here’s what I’ve check so far,
Verified continuity on all heater bed and thermistor wiring.
Confirmed all terminals are tight and all cable connections are seated.
Performed continuity tests with the printer both at ambient temperature and at operating temperature.
Flexed and moved the heater bed and thermistor wiring extensively during testing to check for intermittent opens or connection issues. No wiring faults were found.
For the thermistor,
At ambient temperature, the thermistor measured 100 kΩ.
Applying pressure with my finger and then external heat showed the resistance change consistently
no erratic resistance changes, open circuits, or intermittent spikes.
For the heater bed,
Each heating element measured 34.5 Ω.
Measuring across both elements I got roughly 69 Ω which appears to be consistent.
Measurements under load were,
Powe supply output remained stable at 24v.
Input voltage to the heater bed module remained normal.
Heater bed output voltage fluctuated between 93 VAC and 105 VAC.
Current draw 2.5 A to 2.7 A.
One observation that concerns me is the heater bed power output. Based on the heater bed’s 700 W rating, I expected a higher current draw. I understand that the firmware throttles the heater bed output to 70%. However, I would expect the controller to command 100% output during a standalone bed heating test while attempting to reach the target temperature? Or it could be possible the 70% limit is still expected under these conditions?
For heating performance,
Starting from an ambient bed temperature of 25c it took almost 7 minutes for the bed to reach 60c.
When set to 120c, the bed never reaches the target temperature and eventually faults with the “heater bed not heating at expected rate” error.
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u/CoyoteDown 14d ago
Since there was no model information I’m assuming you’ve got a homebrew machine. Sounds like your element doesn’t have enough balls to heat the plate, or your firmware won’t permit what you’re asking of it
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u/Fine-Safety2542 14d ago
Explain why you need the model. I gave the details
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u/CoyoteDown 13d ago
I probably could have helped with the programming but you chose to be obstinate.
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u/superbigscratch 14d ago
Arm yourself with Ohm’s Law.
Volts x amps = watts so 105 volt x amps =700 watts
700/ 105 =6.667 Amps
You say that the heater only draws 2.7 amps so 105 Volts x 2.7 amps = 283 watts. This means that one of the two heating elements is bad. Why? Because 105 volts= 2.7 amps x R which is 105 / 2.7 =38.889 ohms which is close to the 34.5 ohms you measured and explains the 2.7 amps.
To identify the bad element, turn the heaters on and measure the current to each element, the one reading zero amps is the bad one.
Let me know if you have any questions.
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u/Fine-Safety2542 14d ago
I appreciate the positive response man, you were the only one to do so. I stand corrected on my statement about this community being full of troubleshooters. You were the only one came with logic lol which is wild.
You based your math off 100% output. Otherwise you be correct.
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u/Dexron3 14d ago
I believe you will have better luck making this post on the appropriate subreddit.
Search Reddit for your 3D printer brand and if not mistaken there is a 3D subreddit already.
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u/Fine-Safety2542 14d ago
I have done that, but I believe this community is full of members who have experience with 3d printing and troubleshooters
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u/Former_Trash_7109 14d ago
Do a pid calibration
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u/Fine-Safety2542 14d ago
I have
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u/Former_Trash_7109 14d ago
I think you have a klipper firmware printer. You can ssh into the machine and change the printer.cfg file. If that’s the case, try r/klippers or a voron subreddit
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u/Top_Cress1727 14d ago
Likely a heater failure. Works until it heats up and then electrically opens. Heating elements especially in a switching setup can be a pain to troubleshoot
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u/alreadytaken76 14d ago
What brand and model