X/Y Homing and Direction Issue - Solved

[Scytes]

Printer Model

Voron 2.4R

Extruder Type

Other

Cooling Type

Afterburner

Good morning, as the title suggests I've got an odd issue.

If we SWAP motors A/B on the board so that they are wired with A to motor 0 and B to motor 1 the x and y home and move in the correct direction. However the two axis are inverted this way (X is front to back while y is now right to left)

However if we swap the wiring back to match the original, no matter what i change on the direction pin either one or the other will be backwards no matter what we change.

I've attached the config file we've started with - all axis move in the right direction when doing a buzz as well. So it's just odd it's only during homing but during buzz all works as expected.

 

[shiftingtech]

It's very strange that the motor rotation chart and homing behavior wouldn't match. but you could try plugging the second scenario (the swapped axes one) into the chart, and see where that gets you...

https://docs.vorondesign.com/build/startup/images/V2-motor-configuration-guide.png

 

[Khay]

Just to be clear, you are homing x to the right side and y to the back of the printer?

To add further information to shiftingtech's picture: stepper x = B, stepper y = A

 

[Scytes]

Just to be clear, you are homing x to the right side and y to the back of the printer?

To add further information to shiftingtech's picture: stepper x = B, stepper y = A

Correct - with Stepper X =B, Stepper Y = A, the homing is to the right on Stepper X and to the back on Stepper Y.

If I swap A and B on the board they home perfectly, albeit it X is going to Y and Y is going to X - it's only when we have them connected correctly on the board do they act strange.

Is it possible that just changing the direction in the config isn't enough and we need to invert the connection to one of the steppers to fix it? It's an odd bug for me - I deal with PLCs and servo controls all day and this is just strange lol!

 

[Khay]

I never got the connections and directions right on first try. Understanding the picture, shiftingtech provided, and switching connectors or dir_pin directions, always got it right.

 

[shiftingtech]

Wait sorry.

with Stepper X =B, Stepper Y = A, the homing is to the right on Stepper X and to the back on Stepper Y.

This is the correct behavior. the *entirely* correct behavior.

So what exactly are we trying to fix here?

Are you WANTING the printer to home in some other, non-standard manner?

 

[Scytes]

Wait sorry.


This is the correct behavior. the *entirely* correct behavior.

So what exactly are we trying to fix here?

Are you WANTING the printer to home in some other, non-standard manner?

I'm sorry I should've specified - that is what the homing points SHOULD be and what I'm expecting.

What is happening is X will move correctly but Y will move to the front. If I swap the pin direction for Y in the config it does the opposite - X goes left and Y goes back. Same situation if I swap X then they both change again.

Could it be the belts are on the wrong steppers? I'm troubleshooting this remotely at the moment so I'm just getting ideas for when I get home to fix it.

 

[Khay]

Undo the pin directions, so that it homes X correct and y to the front. now power of the printer, turn it around and switch the connectors between x and y motor aka motor0 and motor1.

now, what does it do?

 

[shiftingtech]

It does

I'm sorry I should've specified - that is what the homing points SHOULD be and what I'm expecting.

What is happening is X will move correctly but Y will move to the front. If I swap the pin direction for Y in the config it does the opposite - X goes left and Y goes back. Same situation if I swap X then they both change again.

Could it be the belts are on the wrong steppers? I'm troubleshooting this remotely at the moment so I'm just getting ideas for when I get home to fix it.

It doesn't sound like you're following the chart I posted.

Let's look. Okay, X is moving to the right, but Y is moving to the front. Okay, that's the bottom left entry in the chart. "steppers are swapped". Okay. So fix that. cross plug the X & Y steppers. Don't reverse any direction pins, just physically swap the two motor leads. Test again.

What happens now?

 

[Sanity Agathion]

Hi, have you managed to figure it out?

 

[Scytes]

Hi, have you managed to figure it out?

Apologies I was just thinking I forgot to post my solution to the issue!

I started from base firmware - updated all my axis directions so they were all the correct direction when buzzing the steppers.

That revealed two issues to me:

1. A belt had slipped off the idler pulley and was causing drag against the other belt so that the steppers could not manage movement properly.
2. I had to invert the connection for Motor A by flipping the pin connector - swapping the direction in the firmware was not resolving the issue but this did when it came to the steppers fighting eachother.

Once I did this the homing sequence worked perfectly and we are not printing!

Thank you for all your help, once I could see the issue in person it took maybe an hour to resolve it all. Troubleshooting remotely sometimes can be confusing!