Noted and thanks Marlark - revert when these are ready to send
Marlark
The new end stop boards have arrived. The cost for these is $10.50 per piece (plus shipment cost).
Please drop me a mail, eero at se dot ibm dot com
Any body else interested - just drop me a e-mail
//Eero
Mail sent 
@patinchuot1
Drop me a e-mail if you are interested in the improved end stop boards, (e-mail address in topic above).
@Velleman - will the pm functionality be enabled at this forum, and if so when can we expect this?
//Eero
Got 4 endstops from Eero today in the mail
Time to put 3 of them on the printer.
// Marlark
Hello!
This is my first day here, and the first day of 3D printing
So i spend the night assembling the K8400, just had some small issue with wrong parts, but today I finished the project!
And now I have 1 problem, and that is my Z-axis Endstop. I first noticed it on the first startup, the led was dimmed and did not light up as much as the others…
So the z-axis just move a couple of mm and then stops, so the controller assume that it is in position!
So I tried to switch the endstops between the Y-axis and the z-axis, but then it does not light up at all 
So my first conclusion was that atleast the photo-sensor is not broken!
I have checked the wires and it´s plugged in as it should! So anybody has some trix or something i maybe have missed?
Sincerer regards //Zimly
Here’s another assumption what to checK:
I assembled the K8400 and could run everything in a proper manner. The home function was acting properly.
Then I started the adjustment if the print head, and afterwards one motor didn’t switch off at home position.
My first assumption was, that I damaged something of the electronics, but the solution was quite surprising:
During the alignment I shifted the pulleys to a position where the belts will run roughly in the middle. Unfortunately this was a little bit too far to the middle of the printer, because guides if the printerhead rods were blocked by the pulleys, so the printhead coulnd’t reach the home position.
Shifting the pulleys a few mm towards the sidewalls of the printer solved the problem.
[quote]Hello all,
I just finished assembling my first K8400.
When trying to zero the axis, all motors continue to run despite having reached the end-of-travel switches. That is not what I expected, and I pulled the plug before the Z axis touch the printing head.
The red LEDs on the sensors are all on. I measured Conejo Valley the voltage on the phototransistors, and I am not very happy - I see 4V when not illuminated, but 0.6, 1.2 and 2.2 V (X,Y and Z) when illuminated. That is far from a logic zero, and I am concerned that the end-of travel sensors could be defective. What type is the photocoupler? Is the current on the LED enough to get a good logic zero?
I stopped testing and will await your answer.[/quote]
Make it sure that each end stop has the correct cable plugged in.