Weird behaviour homing Y-axis (only)

Tomi

@oliof M119 shows the right status and reacts as intended by activating the endstops. Same with the movement of the gantry: before and after the home script it moves the correct way (in all ways XY and Z) – just with this homey.g it's behaving strange…

oliof

@tomi I just noticed

G1 H1 Y310 F10000               ; +Y probe move, fast, set axis limit
G1 H2 Y10 F1000                 ; back off from the endstop, individual motor mode

should be Y-10

G1 H1 Y5.2 F1000                ; +Y probe move, slow, set axis limit

should be Y11 (larger than the backoff)

G1 H2 Y10 F10000                ; back off from the endstop, Individual motor mode

should be Y-10

Tomi

@oliof Thanks oliof: that‘s right what you mention.
But this is exactly the problem. If I use those (negative) G1 movements to back off it crashes into the endstop - not as you expect changing the direction!!!
Only if I keep the positive numbers it goes away from the endstop. As I said: weird!

fcwilt

@tomi said in Weird behaviour homing Y-axis (only):

@oliof Thanks oliof: that‘s right what you mention.
But this is exactly the problem. If I use those (negative) G1 movements to back off it crashes into the endstop - not as you expect changing the direction!!!
Only if I keep the positive numbers it goes away from the endstop. As I said: weird!

What direction do the G1 H1 moves go? Away from or towards the endstop?

And what is the purpose of checking the probe when homing?

Thanks.

Frederick

Tomi

@fcwilt said in Weird behaviour homing Y-axis (only):
Hi Frederik

What direction do the G1 H1 moves go? Away from or towards the endstop?

The G1 H1 moves towards the endstop. Intended behavior in all axes – everything good here. BTW same as when I move the carriage by typing the commands.
The G1 H2 though behaves different:
– on homeX.g it works as we would expect (moving away from the endstop by using «negative values»).
– but on the homeY.g with negative values it moves towards the endstop (it overshoots). Therefore I had do change this to positive values – what seems very silly to me…

And what is the purpose of checking the probe when homing?

I'm not yet probing – and I don't have touched the z-axis yet, because of the described strange behavior. The probing will use the clicky probe (https://github.com/jlas1/Klicky-Probe) combined with the z-endstop (https://github.com/protoloft/klipper_z_calibration).

But this is fiction at the moment: since I don't like a machine not to behave in a predictable manner...

Greetings and thanks – Tomi

fcwilt

@tomi

Thanks for the feedback.

Just FYI:

I have a Euclid Z probe (a removeable type) and I have found no reason to check the mounted state of the probe during homing of any axis other than Z.

I equip all my printers with both a Z endstop and a Z probe. Having a Z endstop speeds homing and simplifies homing code.

As to your Y issue:

It's more than weird it simply shouldn't be happening.

I would suggest you comment out the M913 commands in homeY.g and see if that makes a difference.

Also you need to put a M400 command immediately before each M913 command you use.

Let us know what happens.

Frederick

A Former User

This post is deleted!

fcwilt

@arnold_r_clark said in Weird behaviour homing Y-axis (only):

@fcwilt said in Weird behaviour homing Y-axis (only):

Having a Z endstop speeds homing and simplifies homing code.

How so ?

When you home with a Z probe the X and Y homing code has commands to raise/lower Z to be sure the nozzle is clear of the bed. No need for that with a Z endstop since you first home Z.

And generally you can use fasters speeds with an endstop sensor then you can with a Z probe, but the varies with the specific endstop sensor and Z probe type.

I use optical endstop sensors and you can use very fast speeds with them since there is no impact and they can be mounted so there is plenty of room for movement to stop.

Frederick

A Former User

This post is deleted!

fcwilt

@arnold_r_clark said in Weird behaviour homing Y-axis (only):

When you home with a Z probe the X and Y homing code has commands to raise/lower Z to be sure the nozzle is clear of the bed.

im sorry but that statement is not 100% correct which you tried to cover by stating "but varies with the specific end-stop sensor and z probe type" so in effect your initial statement should be preceded with "in my opinion"

That part about moving Z up/down during homing X and Y does not depend on the type of hardware. It's about being sure nothing is touching the bed during the XY moves.

And the statement about "varying" was part of the sentence dealing with speed and it is not an opinion.

And to throw another spanner into the mix what about a z probe that uses an optical end-stop on its trigger ?

The only device I know like that is servo based and you have to deploy/retract some part of it, which takes time. A Z endstop if fixed in place.

Frederick