Hot Bed doesn't warm until 110C

Dear all,

I'm trying to print ABS instead of PLA (that I have printed until today) and my surprise when I tried to print that the hot bed didn't get warmer than 100C.

My power supply is 500W one.


May someone know what could be wrong?


Thanks!

Once a power supply is adequate, a more powerful one at the same voltage will not deliver any more power to a given circuit. It's probably not wrong. Check power supply voltage. Other than that, without changing your hardware, you may not be able to get 110, but you may not need to either. I've had good results on ABS even with large parts with an 85C bed in a room heated to 25C.

mmmmm

I could try heating the room to 25... because I'm getting a strong warping even with 95 degrees...

I will try and let you know.


Best regards.

What bed material are you using? My efforts were on clean Kapton tape over glass.

Every spool of ABS filament should come from the manufacturer with a 24V power supply for the heated bed. From my own experience and the number of threads popping up in the past month with other people going through the same struggles trying to get a heated bed to reach/hold 110C to print ABS, a lot of people have this same complaint. My 300mm diameter Onyx heated bed would not reach 100C after 45 minutes of pre-heating, but now blows past 110C on its way to nuclear meltdown in 6 minutes running from 19.5V.....

My power supply is 12V... as it's supposed my RAMPS 1.4 only accepts 12V am I wrong?

How would I be able to have it working at 24V? What power supply do you recommend me to? and what about the RAMPS? (if so, where should I connect my 24V in the RAMPS? because there are two entries and it's been a long while I don't touch my prusa so I don't remember which entry was for the heated bed)

Thank you very much! Anyway, I will try later to print with the room at 25 degrees...


Thanks!!

If you are comfortable doing mains wiring, get a 12V 250W LED power supply via eBay and use the adjustment pot on it to increase the voltage to 14V. This will give you 36% more power to the bed. The Arduino and RAMPS will be ok with 14V as long as you do not have an LCD display or anything else powered from the 5V rail.

Edited 1 time(s). Last edit at 02/19/2015 04:38AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I bought a 600 watt, 24V power supply (Mean Well SP-600-24), and switch the bed using an external SSR with a heat sink. To power everything else, I am using a 10A, 24V->12V step down buck converter to make 12V. The price tag was not cheap ($120 USD), but you can't put a price on a 6-minute heated bed warmup. You can probably get away with a much smaller 24V supply, but I wanted some extra capacity for adding extra extruders/heaters and stuff.....

To diagnose this problem properly, you need to use a multimeter. Measure the voltages at the power supply terminals, at the terminal on the RAMPS connected to the power supply for the heater, at the terminals on RAMPS that goes to the heat bed, and at the heat bed terminals with the heat bed on. If the voltage at the power supply is too low, then your power supply might not have sufficient power. There should be very little voltage drop between those measurements. Remember that power, P=V^2/R. So every lost voltage due to resistance in the wires or connectors make a big difference. Unfortunately, since the heat bed is around 1.1-1.2 ohms, it takes very little for the bed to fail to reach 110. If the voltages are right, perhaps the resistance of the bed is too high. This happens. Otherwise, the room might be too cold. I think it would be hard to heat up the bed to 110 if the room is at 20C or below. In that case, put the printer in a box.

Two things you can try:

Insulate the bottom of the heat pad.

Use #12 gauge wire from the power supply to the heat bed terminals of the control board.