Question on Power

Sharpie

I am currently using this heated bed

https://reprapchampion.com/products/3d-printer-heated-hot-bed-pcb-mk2a-300x300mm-pcb-24v-360watt-large-size-reprap?variant=12137585606

and I think my power supply cant handle it

https://www.amazon.com/gp/product/B00D7CWSCG/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

would be getting a new bed work? Or should I swap everything out?

dc42

For a bed of that size (300 x 300mm) you should definitely use either 24V or mains power. That heated bed is designed for 24V according to that listing, but your power supply is only 12V, so the bed is running at one quarter of its design power. I suggest you get a 24V 450W power supply and upgrade the fans and extruder heater cartridge to 24V versions.

DocTrucker

I've got a 300W 24V system that reaches a surface temp of 110C at a 120C set point, I just have to wait 20min or so for it to warm up.

Have you checked the vin voltage when the bed is warming from cold? If the supply drops from 12V then that's an obvious sign the psu is struggling. Check voltage at the bed too, you may be getting a voltage drop in the cabling unless you have already been generous. I'd review the cabling if there is a 10% loss in voltage.

Edit: Didn't spot it was 24vdc bed!

Edit 2: Not sure where I picked up 30A from. More sleep needed…

Sharpie

I have an old ATX power supply that at 500w will that work or would it just be easier to just swap the fans and heater cartridge?

whosrdaddy

it's still not 24V and you will never get 500W on the 12V rail as it is a combined wattage rating

Sharpie

What about this power supply?

https://www.amazon.com/MENZO-Universal-Regulated-Switching-Computer/dp/B06WD5TPYL/ref=sr_1_fkmr3_1?ie=UTF8&qid=1514500914&sr=8-1-fkmr3&keywords=24v+450w+power+supply+3d+printer

Will this work or do you guys know where I can get a 450w PSU?

Martin_S

@Sharpie:

What about this power supply?

https://www.amazon.com/MENZO-Universal-Regulated-Switching-Computer/dp/B06WD5TPYL/ref=sr_1_fkmr3_1?ie=UTF8&qid=1514500914&sr=8-1-fkmr3&keywords=24v+450w+power+supply+3d+printer

Will this work or do you guys know where I can get a 450w PSU?

The bed you linked says it needs at least 360Watt of 24V power to the heated bed alone. That's a 15a 24v PSU.
For everything else, 5a? With a 24v 480w (20a) PSU it should go ok. But if I were you, I would get a 24v 30a PSU just to be safe. It cost just a bit more.

As from where, here they sell 20a and 30a as well:
https://www.ebay.com/itm/AC-110V-220V-TO-DC-5V-12V-24V-Switch-Power-Supply-Driver-Adapter-LED-Strip-Light/152134115704?hash=item236be66178mnohYz4NZlT_Dq5l5lWNUMg

or you could stay with the 12v one, get an AC silicone heater and drive the bed with an SSR.

Sharpie

Ok, I ordered all the parts you guys said to, to address my problem. Thanks again for the help and the knowledge I was going crazy trying to find a straight answer.

just 2 more questions if you guys know.
Do I need a new Thermostat? or is that fine going from 12v to 24v?

I have a 12VDC LED string plugged straight into my power supply, am I going to have to get new LED's or is there a step-down I can place between them?

whosrdaddy

@Sharpie:

just 2 more questions if you guys know.
Do I need a new Thermostat? or is that fine going from 12v to 24v?

I have a 12VDC LED string plugged straight into my power supply, am I going to have to get new LED's or is there a step-down I can place between them?

-> thermistor is fine on all voltages
-> for the leds, just buy a buck converter : https://www.amazon.com/DROK-Regulator-Converter-Waterproof-Converters/dp/B00CERPF0M/ref=pd_day0_23_9?_encoding=UTF8&psc=1&refRID=RWBBCGKAZKTCF5DVK4C5 (just check how much current you need on 12v)

Sharpie

Thanks for all the Help I just completed the 24v upgrade and its printing so smooth and fast.