Inconsistency in calibration (Z-height)

[Airvent]

The issue is hard to explain so please bear with me....

I recently finished my v2 (first printer build) and the calibration was going well until it came to playing with the Z-axis.
Basically, the problem arises when using the "ALL" Movement Controls on MatterControl and when I press "Home Towers" on the printer. Sometimes when I select "ALL", the cheapskates do not rise fully to the top. That's not the main issue, however. 95% of the time, the three skates will go to the top, two of them will hit the end switch (always X-axis and another) and either Y or Z will barely miss it. This causes one of the motors to keep running - if Y doesn't hit the switch, Z keeps going. As a result, the motor skips across the belt and makes a loud grinding sound and also messes up the Z=0 value.

Twice, I have successfully made it past this point to where I'm setting my macros but then the commands (manually entered, not macros) mess it up again.

I have tried changing the tension of the cheapskates, adjusting the height of the end stop screws, and making sure that the skates all start from the same position.

Any help would be much appreciated...thank you

[Dale Eason]

It is next to impossible for a properly built unit to not hit the limit switch metal toggle. Either the switch is not mounted correctly, the metal toggle strip on the switch is not installed correctly, or the screw is not in the right hole. Maybe post a picture of that area.

Dale Eason

[Airvent]

It is next to impossible for a properly built unit to not hit the limit switch metal toggle. Either the switch is not mounted correctly, the metal toggle strip on the switch is not installed correctly, or the screw is not in the right hole. Maybe post a picture of that area.

Dale Eason

It's odd because sometimes they do hit them all at the same time. But they shouldn't have to hit it them at the same time, right? It seems that once two have hit their switches, it prevents the third skate from climbing higher...

Here are some photos: http://imgur.com/gallery/Pgfxr

Thanks a lot for your reply!

[KAS]

Test the M119 command and verify that each end-stop switch is registering for the correct tower axis. example: hold the limit switch with finger and send the M119 command. (that's just to make sure everything is working correctly.) From your explination, I'm guessing that the switches are incorrect on the controller.

If that all works out then you might have the adjustment screw just below the point that the wheels/carriage hit before the switch. I would raise the adjustment screws higher and re-calibrate the machine.

Also, on a newly built machine it's possible that the limit switches might come loose. I press mine towards the very top then tighten so I don't have to worry about the switches being hammered towards the top.

Lastly, it could also be the end-stop switch wires are causing interference. Just make sure the steppers are not passing directly over the limit switch wires on the top plate.

If nothing works, please post a pic of the switches and the controller. Maybe something will jump out that's been missed.


Good luck!

[KAS]

Bah, just realized you linked the top images.

[Airvent]

It turns out I had the end stop wires for Y and Z swapped around. All fixed!

[KAS]

It turns out I had the end stop wires for Y and Z swapped around. All fixed!

Awesome!

[soul_reaper_38]

It turns out I had the end stop wires for Y and Z swapped around. All fixed!

Haha I had this exact same problem when I built mine a few months back! Weird huh? You meticulously follow every step and then randomly make an important mistake here.