Does Opto Endstops cause Ramps to go nuts?

Hello.
I'm new to 3D printing, and i'm nearly done building my very own Prusa Mendel. I've got everything set up and currently i'm working on the endstops.
I've bought all the electronics(Ramps, Arduino, Endstops, Drivers, LCD screen and more) in an all-in-one package.

But i have a problem with the endstops. Most of the time they work perfectly, but sometimes, typically the day after(Without even touching the wires) ramps just goes nuts. The screen goes in low contast, the buzzer goes from buzzing to barely making a noise, and heating either the bed or nozzle takes longer time. Also some of the steppers do not respond when in this weird type of state. It all seems like there is a short, or at least something that makes the board loose a lot of power. Also, removing the plus-pin from especially the Z endstop(Don't know why) makes the printer go back to the correct state, and nothing seems wrong. But also removing either a X or Y plus-pin, helps, but only a little

So, instinctively i looked for any soldering bridges, but i found nothing that could cause a short there.
I've tried almost everything i could imagine, but after a few days, it does it again.

Does anyone know why this is and possibly how to fix it?
Any help is greatly accepted!

I've connected the endstops pins as advised on the endstop and on the main RAMPS board. You can see the connection to the board, in attached file IMG_1. The endstops from the left is: Min-X, Min-Y, Max-Z.

A common issue with Arduino/RAMPS is that the 5V regulator on the Arduino overheats and goes into thermal shutdown. The power needed by the combination of optical endstops and the LCD backlight is overloading the voltage regulator on your Arduino. Possible solutions include:

1. Supply 5V power from an external source to the Arduino.

2. Disconnect the LCD backlight anode from the 5V supply and connect it to +12V via a 180 ohm 0.5W resistor instead.

3. Use a fan to keep the Arduino voltage regulator cooler.

4. Replace your Arduino by a compatible board with a more powerful voltage regulator, such as a Taurino.

5. Ditch the ancient Arduino/RAMPS combo and get a modern controller board such as Duet or Smoothieboard.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

6) Leave the Arduino regulator and power as-is, and add a regulator to fulfill the RAMPS 5v loads (servos, LCD, etc.). The Arduino regulator is more than adequate for just the Arduino . . .

- Tim

Okay..
I just solved it by connecting an USB cable to the Arduino. It works very well now

Quote
tadawson
6) Leave the Arduino regulator and power as-is, and add a regulator to fulfill the RAMPS 5v loads (servos, LCD, etc.). The Arduino regulator is more than adequate for just the Arduino . . .

- Tim

Hello Tim,
I have some problems with my buil also: when I plug in the USB cable or the 12V power line all I can see on LCD is "RepRap PT ver 1.3" then this disappear and all goes white and starts again, over and over...
I have tried to connect to PC using Pronterface and also Repetier but no success. Pronterface does not show any error only "Connecting..." forever... and Repetier give me this: "Serial com errorconfused smileyystem.IO.Ports.SerialErrorReceivedEventArgs" and the baudrate and COM port are set correctly...

( in this thread: [forums.reprap.org] )

Can you please tell me what kind of regulator one can use? Thanks!

The 'low hanging fruit' is a 7805 3 terminal regulator. Others are more efficient, but it's hard to beat simple. Three leads - in, 5v out, and ground, so you can even go so far as to put the in and ground in the 12v input connector to the RAMPS, and use a flying lead to feed the 5v where you need it. A bit 'ghetto', but it works (and I put a 100mfd cap output to ground, IIRC, as well). What little power is lost as heat coming from 12v to 5v, is small enough to be ignorable . . .

The odd thing in your case is that you have the problem on USB power as well . . . . the Arduino regulator is not used when on USB power . . . .

- Tim

Edited 1 time(s). Last edit at 08/17/2015 09:10PM by tadawson.