How to use end stop at max position

Bertrand73

Hi,

I'm building a printer, and I'm currently testing end stop.
I have an issue with Y endstop (which is placed at max Y). When I launch a homming, the first step is OK: the axis go to the top of Y and hit the endstop, after it go backward,and then go back to the endstop. The issue is here: it do not stop or go back at the second hit, it even looks to speed up in the endstop.
I have trie multiple configuration but I did not get something clean...

What are the expected configurqtion for this kind of setup?

Best regards

Repetier

Make sure

#define ENDSTOP_Y_BACK_MOVE 5is a positive value. Negative would be in the endstop and that move does not test endstop! So with negative value you should exactly get your behaviour.

Bertrand73

My settings regarding endstop Y are 

#define ENDSTOP_Y_BACK_MOVE 10
#define ENDSTOP_Y_RETEST_REDUCTION_FACTOR 3
#define ENDSTOP_Y_BACK_ON_HOME 1

I can see the first "back move" as expecting, the issue hapen at the second hit. is there 
any option to configure the second backmove?

Repetier

It goes back to endstop and then execute ENDSTOP_Y_BACK_ON_HOME and that's it. So the slow move to endstop is the planned one and the next move is ENDSTOP_Y_BACK_ON_HOME. Also it should be positive, have you tried if negative works and can you say how far it moves in wrong direction? More then this 1 mm?

Bertrand73

I have done some trial with this config
#define ENDSTOP_Y_BACK_MOVE 5
#define ENDSTOP_Y_RETEST_REDUCTION_FACTOR 3
#define ENDSTOP_Y_BACK_ON_HOME 30

I can see the first hit followed by a back move (5mm), and the second hit followed by another back move(30mm). After this there is a last move of 20 mm in the positive direction. With the ENDSTOP_Y_BACK_ON_HOME set at 30 there is no more crash, but I don't understand the last move