Hello,
I have about 50 outstanding prints against my modified K8200. I have the following mods:
8201 - z axis upgrade
LED ring
12VDC fan connected to PCB case soldered to spare socket on board (40mm .1A PC fan)
This morning, I noticed the bed temp get pulled down to ~44 degrees for the first time.
While printing PLA @ 185, the cooling fan kicked on as usual. As soon as it did, a red LED lit up on the board, and the bed temp began dropping about .1 degree per minute of use. I can hear the fan on the PCB case change RPM slightly. If I turn off the print cooling fan, the bed temp will return to 50 degrees and the red light will go off. I let it dip to 44 or so degrees before I turned off the fan, but I’m sure it could continue to drop so long as the print cooling fan is on.
Do I need to replace the print cooling fan, or the 15VDC main power supply? Can you think of anything else that would cause this?
Thanks,
-D
You should disconnect the extra fan and disable the cooling fan for the filament and retry a print.
If the bed and the extrude temp start to drop check the output of the power supply to see if it’s falling.
This may be the power supply
If the temps stay ok run the filament fan on the next print and watch the temps again.
Just my thoughts
With the print fan disconnectd/disabled the bed temp stays 50 +/- .2.
The extruder has a ceramic blanket and a directed fan shroud and comes in 185 +/- 0.25.
I let it print with everything running and the lowest the bed temp reaches is 43.5 degrees.
Print quality appears unaffected, I’m printing a coat rack for my wife and it is turning out great.
It’s just the dropping bed temp that is worrisome.
Thanks,
-D
Is the room that the printer in cooler then normal?
Actually, Yes. I hadn’t considered that. It’s been about 20 colder since I started the project.
Sure enough, I cranked up the heat to the house and that did the trick.
It appears as if I’m too close to the max performance of this setup, I believe a power expansion is in order. I’m tired of waiting for the bed to heat up, anyway.
Thanks for the help!
-D
Glad that helped.
Environment is everything to these machines.
Update…
All parts came in, and combined with a rained-out weekend the upgrade was inevitable.
The 24VDC 350W power supply dedicated to the heated bed did the trick. Bed temp is now +/- .25 for the duration of the print regardless of my household thermostat. I used a power expander from reprap.me to do the switching. The first board was DOA (I always buy 2 of everything) but the 2nd was good to go. I contacted reprap.me and they will be sending a replacement free of charge!
While I was at it, I switched to a GT2 extruder drive as well.
Thanks again,
-D