Scales- centre Zero?

[John Rudd]

I have now got my X axis scale mounted on my mill and works a treat...

But.....

If I set the table to centre and zero the scales...now move the table to the left, the scale doesnt count down negative from Zero to say 3 inches (if I move the table three inches that is...)

If I move the table all the way to the left( the scale is now at its minimum) and zero the scale it counts up as one would expect...

Is my observation normal and these scales are not suitable for 'about zero' measurement?

What do others do when setting up a working piece and taking readings..?

[Jasonb]

If working from any point you wil get negative one way and positive the other way, never found it a problem. You can set them to give +/- in in your prefered direction, usual is to read up as table moves to left an negative as it moves to the right.

Jason

[Brass_Machine]

Hi ya John  

I have almost the same setup. I use the scales as one would use the dials. Say I am centering a work piece... I zero the Z and use the edge finder til I indicate an edge then I zero out the scale (X or Y). Lift the spindle and move to the opposite side of the piece. Move the Z down until it is zero on the scale (the Z scale) and find the opposite edge. Then take the reading from the scale (X or Y) and divide by half. lift the spindle and move to that number (the divided number). Re-zero the scale and you have one of the axes centered on your work piece.

Hope that helps

Eric

[John Rudd]

Thanks for the replies chaps...


I played around with the scale off machine, it seems to work somewhat erratically .....

I think it might just be a greasy surface... or mebbe a defective scale?

The Y axis scale appears fine...

[Jasonb]

Then take the reading from the scale (X or Y) and divide by half. lift the spindle and move to that number (the divided number). Re-zero the scale and you have one of the axes centered on your work piece.

Don't you just press the 1/2 button when you pick up the second edge, no need for calculations and you don't have to move back to the centre and set to zero.

Or are you both talking calliper type scales rather than proper DROs

Jason

[John Rudd]

Or are you both talking calliper type scales rather than proper DROs

Jason

I'm talking caliper type........

[kvom]

If the table is moving left the tool "moves" right. which is the + direction normally.