hot end unable to maintain temperature when part fan on

I have a scratch build with lots of custom this-n-that on it. No heated bed, uses a 6Amp 12V laptop supply for power. It has been running for over a year now with no issues, suddenly it has had problems maintaining temperature when the part fan is on more than 50%. I have replaced the heater, thermistor and even the power supply. Still there. I am using some integrated controller, Mk 1.3, Rumba, something like that. How common is it for the controller's output to "weaken" like that? Is there some other thing I should look for? Did the part fan suddenly gain super powers?

I am scratching my head.

DLC

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Kits: Folgertech Kossel 2020 upgraded E3Dv6, Anet A8 upgraded E3Dv6, Tevo Tarantula enhanced parts and dual-head, TronXY X5SA Pro(E3DHemera).
Scratch: Large bed Cartesian, exchangeable heads, Linear slide Delta, Maker-Beam XL Micro Delta, 220x220CoreXY.

If you have a volt meter measure the voltage on the controller power pin when having problems maintaining temperature.

This will eliminate the power supply as being a problem

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Computer Programmer / Electronics Technician

Quote
Roberts_Clif
If you have a volt meter measure the voltage on the controller power pin when having problems maintaining temperature.

This will eliminate the power supply as being a problem

That is next on my agenda, these LED PSU's are not known for their robustness, it may have just failed. Yesterday it worked, today, not. But, to have a failure, there must be some discrete point in time where the transition between works and doesn't work has to occur. However, I ran it on two different PSU's, so... Gotta check.

wash your hands,
DLC

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Kits: Folgertech Kossel 2020 upgraded E3Dv6, Anet A8 upgraded E3Dv6, Tevo Tarantula enhanced parts and dual-head, TronXY X5SA Pro(E3DHemera).
Scratch: Large bed Cartesian, exchangeable heads, Linear slide Delta, Maker-Beam XL Micro Delta, 220x220CoreXY.

Still 6A sounds like a little bit of a low Current to run 3x steppers + hotend (40W/3.3A). Imagining the stepper motors pull around 1A when in use that's already 6.3A when the printer is heating up AND moving. This is putting the LED PSU to it's limits. Then there is a bit of extra needed for the LCD panel, the logic stuff going on on the Mega+Ramps and then some fans etc. I would guess this could be the issue.

However. I have designed a CoreXY pen plotter with three steppers running on 800mA each and a 2A PSU is running the entire machine (Mega + Ramps + controller fan + LCD) without problems. So there's theory and there's practice. Of course a 3D printer has a heavier X-carriage and a heavier printbed to move around. My pen plotter has superlight moving parts and small diameter pulleys. The moving axis only has one aluminium extrusion and one v-slot cart. The pen is moved up and down with a thing string through a bowden tube so it all weighs next to nothing.

Edited 1 time(s). Last edit at 07/14/2020 03:08PM by Ohmarinus.

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http://www.marinusdebeer.nl/

As it turned out, the heater was not firmly held in the heater block. Tightened it up and all is good.
Forgot to mention that.

DLC

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Kits: Folgertech Kossel 2020 upgraded E3Dv6, Anet A8 upgraded E3Dv6, Tevo Tarantula enhanced parts and dual-head, TronXY X5SA Pro(E3DHemera).
Scratch: Large bed Cartesian, exchangeable heads, Linear slide Delta, Maker-Beam XL Micro Delta, 220x220CoreXY.