I have been having an issue with my heater bed keeping up with a print anytime I have any kind of fan going. I was able to block the air (from the extruder fan) from hitting the bed and that works. When I install a fan for the nozzle though, the air from that cools the bed and it shuts down the print. Does anyone have some tests I can run or have a seperate psu idea for the bed? It's for a folgertech prusa i3. https://reprap.org/forum/read.php?262,503727,503727#msg-503727 Tue, 10 Mar 2026 14:46:49 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?262,503727,504148#msg-504148 https://reprap.org/forum/read.php?262,503727,504148#msg-504148
1. Cheap printer electronics such as Arduino Mega/RAMPS may not tolerate much more than 12V input to the board as a whole, especially if you are running additional loads from the 5V output, e.g. LCD display. Without a LCD display or other 5V loads, Arduino Mega is OK up to about 15V.

2. The PSU has a rated power, therefore if you increase the output voltage, the maximum current you can safely draw from it decreases in proportion.]]> dc42 Printing Fri, 01 May 2015 16:16:45 -0400 https://reprap.org/forum/read.php?262,503727,504126#msg-504126 https://reprap.org/forum/read.php?262,503727,504126#msg-504126 drHEEB Printing Fri, 01 May 2015 15:35:23 -0400 https://reprap.org/forum/read.php?262,503727,503960#msg-503960 https://reprap.org/forum/read.php?262,503727,503960#msg-503960 I tried to get the bedtime up to 110, and maintain at 90 during print.
It is something related to the amount of power that the heated bed can/will use.
I have a work around for this: Cover the bottom of the plate with cardboard to prevent air from taking away the heat, and cover the top with a rag or cardboard, when it is heated up, remove top cover and start the print.
The first layer at 110 is relatively okay(it wil drop!!), the rest of the layers at 90 should be okay as well, might drop to 87, but it will maintain the heat better by the covered bottom.

I hope this helps you as good as it helped me, but make sure you check the cardboard from time to time, i do not have any scorch marks, but i cannot guarantee the cardboard will hold in your case as well, just be careful and watch what happens in the beginning.]]> Hipnotize Printing Fri, 01 May 2015 08:23:54 -0400 https://reprap.org/forum/read.php?262,503727,503918#msg-503918 https://reprap.org/forum/read.php?262,503727,503918#msg-503918 dc42 Printing Fri, 01 May 2015 05:09:02 -0400 https://reprap.org/forum/read.php?262,503727,503852#msg-503852 https://reprap.org/forum/read.php?262,503727,503852#msg-503852 ggherbaz Printing Thu, 30 Apr 2015 22:26:54 -0400 https://reprap.org/forum/read.php?262,503727,503848#msg-503848 https://reprap.org/forum/read.php?262,503727,503848#msg-503848 ggherbaz Printing Thu, 30 Apr 2015 22:13:59 -0400 https://reprap.org/forum/read.php?262,503727,503845#msg-503845 https://reprap.org/forum/read.php?262,503727,503845#msg-503845
Disconnect the bed from the ramps and plug it straight to the power supply and while watching on temperature turn on the fan, if same effect you can discard board issues and reduce it to wiring or under power issues. Next connect a fan and heat bed to power supply and power your board only with USB cable so the power goes only to bed and fan but you can see temperature on your computer, if problem percist check the wiring and solder points if all ok then problem is underpowered supply.

If you have a multimeter check bed ohms against manufacturers data, if your bed is a dual 12-24 volts and is set for 24 and you are supplying12 it might fail in same fashion.]]> ggherbaz Printing Thu, 30 Apr 2015 21:55:31 -0400 https://reprap.org/forum/read.php?262,503727,503816#msg-503816 https://reprap.org/forum/read.php?262,503727,503816#msg-503816 drHEEB Printing Thu, 30 Apr 2015 20:27:26 -0400 https://reprap.org/forum/read.php?262,503727,503812#msg-503812 https://reprap.org/forum/read.php?262,503727,503812#msg-503812 drHEEB Printing Thu, 30 Apr 2015 20:10:11 -0400 https://reprap.org/forum/read.php?262,503727,503800#msg-503800 https://reprap.org/forum/read.php?262,503727,503800#msg-503800 drHEEB Printing Thu, 30 Apr 2015 19:10:08 -0400 https://reprap.org/forum/read.php?262,503727,503778#msg-503778 https://reprap.org/forum/read.php?262,503727,503778#msg-503778 drHEEB Printing Thu, 30 Apr 2015 18:01:05 -0400 https://reprap.org/forum/read.php?262,503727,503771#msg-503771 https://reprap.org/forum/read.php?262,503727,503771#msg-503771 ggherbaz Printing Thu, 30 Apr 2015 17:21:51 -0400 https://reprap.org/forum/read.php?262,503727,503727#msg-503727 https://reprap.org/forum/read.php?262,503727,503727#msg-503727 drHEEB Printing Thu, 30 Apr 2015 15:41:46 -0400