As per the parts list I bought the ramps 1.4 and the arduino mega. When I look in the build instructions under electronics there isn’t a mention of the arduino board. Whats it for? And as far as the resistor goes, I see where it’s supposed to go, but how do you attach it?

Also, what kind of glue for the heatsinks?

Update: All my questions were answered by simply looking at the board except for the resistor question. I’m an idiot by the way.

Can you add a fan to cool the board if it’s in a case? Where would it Jack to?

Also, my ramps board seems to have two sets of pins for the z motor. Do I just pick a set?

A fan should get plugged in on the other side of the green plug, most just connect it at the plug itself but it is best practice to not draw any extra current through the plug.

Thanks. I did just edit my post above thinking I beat anybody to answering yet. I’m still confused about the resistor, more or less how it is attached to the board. And if I just pick a set of pins for the z axis. I’m sorry I’m taking up so much of your time.

Also, could you use the 12v plug on the mega instead of the ramps board to provide a feed?

If you bought the parts here the resistor should have had a couple of connectors on it that plug into the pins sticking up from the RAMPS. If you didn’t get the parts here you should put the correct female connectors on to match those pins. You can also use a two socket connector with wires and solder the resistor to the wires. The key is to simulate a temperature so you don’t have to tweak the software to work in a non 3D print environment.

thanks for this thread. I was about to solder the resistor in place. I’ll wait and get a proper connector. (I’m not that good at soldering)
I did want to bump the question of the 12v connection. The powersupply I bought, which I believe was the recommended model has the 12v plug for the Arduino. is this sufficient? or should I cut/strip and install in the green power connector on the ramps board? or does it not matter?
Thank you!
(getting awfully close after waiting 3 weeks for China Post to deliver the ramps board)

If you have an extra thermistor or fan from a 3D printer laying around you can use the connector from that. Cut the wires short and solder one side of the resistor to each wire.

You need to put 12V on the green connector on the RAMPS. If you don’t you won’t have power to the steppers.