Hey Guys, I'm building either a Rostock or a PM i2, and using RAMPS I haven't actually bought the electronics yet, but I know I'm going to want a heated bed, and lcd panel, and all of that good stuff. Eventually, I hope to have a dual extruder setup. My question is, how do I determine the amperage I need. I've looked at this with this. The other one I looked at was this with this. Also, I plan to have an extruder fan cooling the print, and if I go with a Prusa, a fan cooling the Pololu z-axis stepper driver, because I read that that gets hot driving two steppers. I already have a PSU, meant for a computer build. It is 12V, 550W. When I did the math, that came out to about 46 Amperes. Can too many amperes damage my system? Is it okay for me to use that? I'd prefer to go with a system meant for a printer, because the supply I already have has a bunch of wires sticking out (meant for attaching to hard drives, fans, etc., etc. in a computer), and I would have no idea where to start conencting that to the Arduino, and would probably fry my electronics. Please help me figure out what kind of power supply I should get! PS the other reason I kind of don't want to use the computer PSU is that it's relatively big and ugly-looking...it's ATX size. Thanks!:) https://reprap.org/forum/read.php?219,219857,219857#msg-219857 Tue, 19 May 2026 15:18:46 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?219,219857,221950#msg-221950 https://reprap.org/forum/read.php?219,219857,221950#msg-221950
12V 30Amp Regulated power switching PSU]]> RicardoGA RAMPS Electronics Thu, 27 Jun 2013 05:05:13 -0400 https://reprap.org/forum/read.php?219,219857,220005#msg-220005 https://reprap.org/forum/read.php?219,219857,220005#msg-220005 chris33 RAMPS Electronics Thu, 20 Jun 2013 09:24:26 -0400 https://reprap.org/forum/read.php?219,219857,219874#msg-219874 https://reprap.org/forum/read.php?219,219857,219874#msg-219874 jbernardis RAMPS Electronics Thu, 20 Jun 2013 01:31:27 -0400 https://reprap.org/forum/read.php?219,219857,219864#msg-219864 https://reprap.org/forum/read.php?219,219857,219864#msg-219864 evamvid RAMPS Electronics Thu, 20 Jun 2013 00:00:25 -0400 https://reprap.org/forum/read.php?219,219857,219860#msg-219860 https://reprap.org/forum/read.php?219,219857,219860#msg-219860
I actually have a power supply similar to your second link, but I got mine on ebay and it's rated for 30 amps.

Basically your RAMPs has two power rails, one for the heated bed that is rated for 11 amps. The other for hot end(s) and motors is rated for 5 amps.
So that all totals 16 amps. If you tried to draw more amperage than that through the RAMPS board, you'd probably start tripping your fuses.

Generally speaking, unless you go overboard, the amperage drawn by LCD's, fans and such is inconsequential. I guess you can get into higher drawing fans, but if you're talking about small PC types fans, the 20 amp power should be more than enough.

The only thing that i hesitate with is the current drawn by a second extruder, but I guess the RAMPs is engineered for it, so I guess it would fit into the overall 5 amps on that rail.]]> jbernardis RAMPS Electronics Wed, 19 Jun 2013 23:07:27 -0400 https://reprap.org/forum/read.php?219,219857,219857#msg-219857 https://reprap.org/forum/read.php?219,219857,219857#msg-219857
I'm building either a Rostock or a PM i2, and using RAMPS

I haven't actually bought the electronics yet, but I know I'm going to want a heated bed, and lcd panel, and all of that good stuff.
Eventually, I hope to have a dual extruder setup.

My question is, how do I determine the amperage I need.
I've looked at this with this.
The other one I looked at was this with this.

Also, I plan to have an extruder fan cooling the print, and if I go with a Prusa, a fan cooling the Pololu z-axis stepper driver, because I read that that gets hot driving two steppers.

I already have a PSU, meant for a computer build. It is 12V, 550W. When I did the math, that came out to about 46 Amperes. Can too many amperes damage my system? Is it okay for me to use that?
I'd prefer to go with a system meant for a printer, because the supply I already have has a bunch of wires sticking out (meant for attaching to hard drives, fans, etc., etc. in a computer), and I would have no idea where to start conencting that to the Arduino, and would probably fry my electronics.

Please help me figure out what kind of power supply I should get!

PS the other reason I kind of don't want to use the computer PSU is that it's relatively big and ugly-looking...it's ATX size.


Thanks!:)]]> evamvid RAMPS Electronics Wed, 19 Jun 2013 22:34:28 -0400