LR3 Homing Directions

Hey BrainsTrust.

I am at the time of getting the wiring correct and testing homing. I have all the motors moving in the “correct direction” with each other however when clicking “Home” on the TFT the following things happen:

  • Z moves up towards the top end stops.
  • Y moves towards the back (so away from the end stop)
  • X moves to the right (away from the end stop).

My question is should I be flipping the motors to head towards the end stops, and should Z go up?

My second related question is, I have Z2 and Y2 on the left of the machine (where the TFT is) - should that side be Z1 and Y1, or it doesn’t matter as long as the end stops match the side?

Thanks in advance!!!

So close now to getting some crown action

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That all sounds right. The Z homes up. X and Y home down.

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First question. Z should home up, until it triggers the switches. X should home to the left from your picture. Y shoul home towards the camera from your picture. Flip the motor plugs if this is opposite.

Second question. It doesnt matter, so long as your endstop switches match the motors. I made a mistake and Y1 and Z2 are on the left hand Y plate, but it works, so I will leave it be.

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Also, if your endstops are wired wrong they will move the wrong way.

So first test. The manual movements are correct. Up is up, right is right, Y+ is away from the camera. Those are the only reason to flip the plugs.

If the machine moves away from the switches, verify the connections with M119 in a terminal.

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Cool thanks for that! That makes sense. I’ll get some flipping of the motors so they move towards the end stops. I had them the other way as the arrows on the TFT (which are behind the machine) are pointing the other direction - specifically X and Y.

I’ll just flip the screen to point forwards and everything should be perfecto.

Thanks!

That’s interesting. I thought flipping the motor plug would switch direction. Your saying doing a m119 which is end stop related would also change the direction movement? I thought this would just stop it from detecting a trigger.

Thanks!

Flipping will change direction but the truth is always manual movements. Homing CAN go the wrong way.

M119 reports the status of the triggers.

If the switches are wired wrong, what the “home” button will do is move the machine about 5mm in the opposite direction, because it will see the switches as “triggered”

This is because the home sequence goes as follows:

Move the machine towards the endstops until the stops report triggered. (In this case, this is immediately, so we probably just don’t even see the 1/100th mm movement towards the home switches)

Once all the stops report triggered, move the machine back 5mm (Or a firmware determined preset amount) away from the trigger. (In this case, it would be the movement that we see)

Now move towards the trigger more slowly to get a more precise detection of the trigger position. Stop when the triggers report a positive. (Again, we would not see this movement.) If the movement is too small or too big, Marlin will often report this as an error condition.

If the movement is more than about 15mm, I would assume that the endstops being wired wrong, or unplugged is not the case, and that the motor wires should be flipped.

My screen is facing the side of the machine, so it takes some mental gymnastics to equate “right” as away from the screen, and “away” or “up” as movement to my left, but I don’t even think about that now. It might give me some trouble with a joystick though.

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Ahh awesome this makes complete sense on why it would reverse.

Thanks for spelling it out, greatly appreciated!

:pray:

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Confirming we are homing nicely now, and the screen is actually pointing the right way (can’t believe I didnt think of rotating the screen lol).

Thanks!

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