HELP!! I have a prusa mendel, with the sanguinololu 1.3a.
How can i use a second powersupply for my heated bed? Now my heated bed won’t go over 67 degrees celsius wich causes my abs prints to warp and snap loose from the bed.
Are these (red pcb) heated bed’s even able to go over that temperature? For the rest my powersupply seems to be sufficient (30A @ 12V)
I use a 2nd power (~220 to 12V) switched by an Solid State Relais
I tried that once but the only solid state relay i could get whas a AC one. When you attach a DC power source to it, it doesn’t work. Or at least in my case…
Wich type did you use? And on what pin did you attach it?
I use SSR-25 DA. The source input is connected to the bed output of the ramps.
Your power supply you’re using should be sufficient, but it may not be outputting the power it’s supposed to. If you’re in a country that uses 110VAC power, you might have to flip a switch in the power supply to get the proper output. They typically some factory set for 220VAC input, because Very Bad Things can happen if you plug a power supply expecting 110 into 220, but in the reverse case it will just underperform until you set it correctly.
@Whosa_whatsis i’m in europe everything is 220V here. Thanks though!
@Olivier_KUNTZ thanks i will look for that one.
@Olivier_KUNTZ i had a look at this ssr. But this one i allready tried. It is a AC relay. If you use DC, it won’t work. (At least not with me). Or are you using an AC Powersupply for the bed?
If you want to use a separate power supply for the heated bed, just tie the two grounds together and attach the new power supply’s positive terminal to the platform instead of the one coming from the board, no SSR required. Shouldn’t be necessary, though.
@Mano_Biletsky_Open_M :The SSR switch on/off the power supply.
@Whosa_whatsis : I don’t understain what you do. Do you have schema?
No diagram, but I’ll see if I can make it more clear:
PS1 V+ -> controller V+
PS1 GND -> controller GND
PS2 GND -> controller GND
PS2 V+ -> platform V+
Controller HBP negative output -> platform negative input.
This works because the MOSFETs that control the heaters are N-channel, so they connect/disconnect the GND side. The two power supplies don’t even have to be the same voltage.
@Whosa_whatsis That’s genius!
Have you tried to isolate under the hotbed ? I had same problem first time i assembled my prusa i3 , i reached 80 degre penibly , then i solved it with adding isolation under hotbed , i used a little panel of réflective heat : http://www.promeca.com/images/PAREFX3.jpg
Then now i reache 110 - 180 degre easily ^^
You should use some abs juice too . In a bottle u put acethone and abs peace . Befor starting ur printing , put some of this juice with a paper towel on the hotbed. When acethone evaporate , thats gonna leave a layer of abs on the hotbed ,who improve adherance of ur first layer filament ^^
@partouche_michael i have expirimented with different types of insulation, but they all slow down the heating up time and the max. temp is lower than before. I guess i really need to add a second power supply…
