First build, electronics help

Hey guys I'm attempting to build my first 3d printer. I'm building on an aluminum single frame i3. I'm confused as to what electronics I would need. I want to use RAMPS 1.4 so if I decide to add a second extruder at a later date I can. I know I need an arduino board as well. What confuses me is sainsmarts A4988 driver. Are these needed? Aren't the stepper motors controlled by the RAMPS board? Everything else I can understand. Electronics have never been my strong point. I can solder because it was needed for my other hobby, custom auto and motorcycle harnesses. Other than that I'm lost....any help would be appreciated.

The RAMPS board has open slots into which you need to put stepper drivers. That way you can upgrade the stepper drivers, or replace them if they burn out.

Not all electronics have removeable stepper drivers. Some of them are part of the board.

Get stepper drivers with heat sinks. They usually come separately and have special double sided tape to hold the heat sink onto the tiny chip on the stepper driver modules

I've bought several sets of stepper drivers very cheaply on eBay and so far they've all been fine.

Also, I'd recommend you get a 12V fan and continuously cool the ramps board, as the stepper drivers can get hot, and the FET for the heat bed definately gets hot.

I'd recommend you have a heat sink on the FET (transistor) that drives the heat bed, otherwise it can get too hot to tough.


Also, get a decent quality power supply. Many people have posted about issues with the power supply. checkout the various postings on the forum about power supplies and heat bed PCB's they normally go hand in hand.

To a great extent a Ramps board is a whole bunch of jumper wires and bypass capacitors. The main electronics are the MOSFET switches. It's a very useful bunch of jumpers so you really need something like it.

Get a 12 or 15V industrial supply rated around 30A to go with the board. They will be adjustable so you can set the voltage to a point that everything woks ok.

I say stay away from the dedicated 12V power supplies. Get a good quality computer ATX power supply. Switched/regulated/protected 12V power with plenty of current, short-circuit protection, and a 5V rail to boot; YAY!!

A computer supply is designed for something very different than running a printer. They do not have a reasonable set of outputs for a printer. They may or may not supply the current you need. The outputs are not adjustable and are rarely very close to what you would want them to be. They often have strange interdependence between the various outputs. They are poorly protected against shorts and rarely protected against over voltage. If you get an off brand they are cheap and short lived. Unless you buy a lot of them, knowing what is good and what is bad is not at all easy. If you do go for a good one, generally cost as much or more than a good quality industrial supply. There is nothing to recommend them in this application.

The one feature the ATX power supplies have that is a positive is the ability to turn off the power under g code control. This is great for unattended operation.

Having said that, I agree with uncle_Bob on this one. I prefer the industrial power supplies. My first was purchased off of eBay, and it lasted for about 18 months before it failed in a way that could very well have ended up causing a fire if it had been unattended. I have since purchased a mean well 30 amp PSU, and the difference in build quality is night and day. The difference in cost between eBay and the mean well distributer was about $15. So although I would recommend the industrial supply, I would also advise to not go cheap.