Hi all- I am designing and building my own 3D printer from scratch. I think I have made my first mistake. So I bought this extruder: [www.ebay.com] and it is rated for 24V. I, however, have also bought NEMA 17s that are rated for 12V (part number 17HS3001-20. The way I see it I'm going to have to run everything on 12V or 24V. Do you guys see any other solutions?

Voltage on steppers isnt really a useful number on modern controllers... (unless it to high)

You will be able to run your 17HS3001-20 on 24 volt without issues
In fact the product page even says so [www.robotdigg.com]

Ah thanks for the input. So what are the problems associated with running RAMPS 1.4 on 24 volts? I have read that certain boards' capacitors are under-rated for the job. Also, can the Arduino Mega handle 24 volts or is there a regulator on the RAMPS that will drop input voltage down?

Thanks again for your help.

Yes your correct on both counts.

Ramps boards need to have 35v caps to work at 24v. (some have 16v), secondly the 12v 11amp polyfuse isn’t rated for 24v, you need to replace that (most are using car fuses)

And yes the standard Mega board can't take more that 12v. You can remove d1 from the ramps and power the Mega separately, or the much simpler option is get a Taurino Power (must be the power version) , a redesigned just for reprap version of the mega that can take 24v, and you don't have to worry about any diode stuff. [www.reprapdiscount.com]#

You also need 24v fans and probably Heated build platforms.

Edited 1 time(s). Last edit at 02/08/2014 12:16AM by Dust.

I would also remove the power fets and mount them externally with heat sinks. They might get hot at the higher voltage (are they rated for it?)
You also might consider using the DRV8825 based stepper boards, they can handle more voltage as well,

Edited 1 time(s). Last edit at 02/08/2014 10:37PM by kscharf.

I just upgraded to 24v, and while it takes a bit more effort, it leaves you with a better-behaved machine.

I removed the RAMPS fuses and shorted the connections, then put inline fuses from my 24v power supply to the board.
I'm using a lm2596 to step down to 5V, which I put into the RAMPS pin that sends it to the Arduino.
My steppers and Pololu A4988 driver boards are unchanged, though I needed to adjust the trimpots waaaay down.
If you're putting 24V into a PCB heated bed, you must get one that is built for 24V. Otherwise, you'll get too much current. The improved performance of a 24V bed is worth the upgrade hassle all on its own, I feel.

You might also consider getting a nozzle that is larger than .3 for your first go at this. The smaller nozzles have an increased degree of difficulty, and I don't recommend making *everything* more difficult the first time around.

Good luck!

you might change only the heat block for the hotend to another one 12v and you done, after every thing come ok and your printer tuned you may upgrade it to 24v as mentioned.