Fiducial pin

[Guest]

Hi Roby,
I have a problem we the location fiducials pad (tip #038).
We need to put this because the assembly machine needs to it to place the smd components.
Now the question is, you placed everywere you wanted!!!!
You put them where near the corners and said there are no empty space, but how machine uses them as references. Because it is not in the origin of 0,0.
Moreover as I know, we need three fiducials on on origin 0,0 other in 2 other side of origin 0,y and x,0 but you used 4 fiducials.

[Paul van Avesaath]

In General it sup to you how much you use and were to put them,
how ever a nice rule of thumb is 3 on the top and 3 on the bottom (preferrably the exact same location )
and spaced to the edges.. you can put them close to eachother, but it makes more sence to space them further apart. most manufacturers prefer it that way.

the origin is set to one of the fiducial locations. so it will be automatically 0.0, but the other two do not need to be inline with the "y"and "x"

[robertferanec]

Guest, Paul van Avesaath answer is good.

PS: It may not be necessary to place it to 0.0 - I never do it and it is fine. But assembly house like to have three fiducials on lines which are crossing each other with 90Deg angle (that is basically what you achieve by 0,0 ; 0,x; y,0). They like three fiducials because the machine would recognize if the board is inserted wrong way (if board rotation is incorrect).

[Guest]

Thank you roby,
As I understood, we have use origin 0,0 always at the corner of board (sometimes I used it at middle of the board ) and we use three fiducial at the corner yhat the machine is able to recognize the correct rotation of the board