Double Endstop Idea

Oh and if it works, can you guys do it for all 3 axisseses?

Edit:...i keep staring at the GIF thinking its gonna print me something.

nice idea

except that it wont ever know if its hitting the + limit or the - limit... so it doesn't know if it needs to reverse or forward to come off the end stop. Net result is at best it can emergency stop the printer... then you;d need to re-home everything again as it would loose its print co-ordinates...

So mechanically sound... but not so sound as far as adding additional 'end stops'....
Just buy a RAMPS board and then you can have a proper +/- end stop pair... would be more reliable and functional than the above

Could you just wire the endstops together? You would have to change the code somehow so it knows which endstop it hit based on the direction it was going.  If it registered an X endstop hit while the printer was moving left, then it can guess it was the left (-X) endstop.  An X endstop hit while it was moving right would have been the +X endstop.

My original idea was just to make everything stop and maybe home itself if either side reached it's limit. I was tired of the motors banging against the sides that dont have endstops and making that terrible noise (due to my own click-happy fingers of course). I would think that if an endstop gets hit while printing, the print should be aborted anyway because it means the model is too big to fit and should be resized, no?

Howcome you guys want it to continue printing? (Im not asking sarcastically im just curious.) And if it did continue to print, how would it print since it's already reached its linear limit? Would it ignore the remaining distance and just make a flat wall?

Mybe if I understood how electronics work... To me everything with electronics works off of magic and pixie dust.

How can I do?

Also how would you wire it? From the way I thought how things work is that the endstops make a closed circuit when they are hit and it makes the motors stop. And, of you wired 2 together using the same terminals, they will never make a closed circuit because one side will always be open... Like i said, i have no clue how things really work just what i though happens and my reason for coming up with the original idea.

I would much rather mount another endstop on the otherside if all it meant was soldering 2 wires together. (And you guys do the pixie stuff)

So, I could have gotten the same effect by cutting and pasting some text to the firmware?
:-(

I really should learn stuff...

The software endstops do depend on a habit of homing.  After a restart, and if you move it around with the motors off it will lose track of where it is.  It can either allow a crash or stop halfway across because it thinks it is at the end.  Hitting home all every time you finish doing something will help it work better.   I suspect Repetier itself does some software endstop function on its on based on printer settings but I'm not sure.

The ICSP ports. Check the sanginololu schematics on the reprap wiki, but they are the top right group of 6 pins if you look at the card from the rear

http://reprap.org/wiki/File:Sanguinololu_1.3a.png

In this pic, they are the bottom-right group of 6:

Don't worry about hooking up the +5V if you power it via USB when you are programming it. This is the only vague potential 'cause something to get fried'... Choose ONE way to power the Sang... USB, the Standard Mains, or via the Programmer and the 5V pin in the ICSP group.

You WILL however need the Gnd connection. Then from the programmer its a matter of hooking RST to Reset, MOSI to MISO, and MISO to MOSI (these are essentially 'in and out' or tx/rx.. but they aren't, so lets move on...) and SCK to the Clock pin on the programmer (often labelled CLK) .

Thats all you need..

This hasn't quite been mentioned but you can't use a single endstop switch for both for the simple reason of starting point.
When the printer comes on and the endstop switch is already activated which way do you move?
There is no last movement direction info, well unless you modify the firmware to store direction changes to the EEPROM every time but I doubt that would last long and it sure would slow down printing.

Nice idea to try and stop it crashing as an Estop, but then your printer gets stuck and needs manual intervention.

As Adrian said, software limits are the simple solution as long as you home all axis before printing (or playing about )