View Full Version : perpendicularity

10-16-2004, 01:46 PM
Hi ,
I am an electronics engineer and have been able to make stepper motor drives and build my RS232 interface board for a pcb drilling software, but i have completely failed in building a good XYZ system with all axes perpendicular to each other.
As a result, what should have been drilled along a rectangle is being done along a parallelogram.

Any guidance as to what I can do to get things right.


10-16-2004, 02:41 PM
Often this is because the 'compliant' side of a X axis gantry is not being followed faithfully by the 'Non-compliant' side,especially if only one side is driven, is there a change in the parallelogram with a change in direction of X axis, if so there is flex from one side to the other. If the X axis is carrying a fairly high load, weight of the Y etc, as well as the force created by cutting, you may have to couple the drive from one side of the gantry drive to the other side if this is not already in place.
If there is no flex then you should put in place a method of adjustment to square up the y to the x by cutting a series of trial and error rectangles.

10-16-2004, 02:50 PM
Mine is only a PCB drilling machine, with the Y axis mounetd on the X.
If I do according to what you say shall work only with little accuracy, how does one achieve the perpendicularity between these two axes to retain the error within a couple of mils along a travel of about 18"

10-16-2004, 04:02 PM
There are several way of achieving this, but it would be best if you indicate how you have constructed it so far, if you can show pictures that would help.
Also have you tried locking the driven side and see if you can move the opposite side to see if there is inherent flex across the table from side to side?

10-17-2004, 09:02 AM
yes, please post pictures. A visual can reveal where the machine can be aligned through adjustment...and where it fails in maintaining your desired tolerances.
let's see some pictures... :)