If your DRO system has the ability to remember multiple zero positions it doesn't really matter when you are going to be the only person using the machine. Just make sure you know how its set.

I view the table movements as being Cartesian co-ordinates with zero in the centre of travel, X going negative as the table moves to the right and Y going negative as it moves towards me. Other folk do it differently. You will have to experiment to get the hang of curve cutting. If your system is anything like the one on my Sino SDS2M system you will find it effective but needing considerable patience. Think CNC experience by manual moves. I did one job and decided life was too short! Admittedly a fairly ambitious job.

My Z axis is on the knee of my Bridgeport. I find it convenient to have Z negative corresponding to downwards movement of the knee i.e number goes up as the distance from cutter to work increases. I pay little attention to where zero Z actually is resetting whenever needed. I usually touch off the work with the end of the cutter, set to zero and move as needed until the correct depth of cut has been reached. Other folk prefer to set zero to the finish depth of cut which has advantages in that you always know where the end of cut is.

I frequently set temporary zero positions in X and Y axes depending on works best for the job. Invariably set to set to zero when using the 1/2 function to find the middle of a workpiece or part there-off.

I always work in absolute co-ordinates. Working relative can save some messing around with zeros but I don't like the potential for getting lost.

One fixed zero memory. No 1 is centre of X & Y travels. Always select that one and move back to zero-zero before shutting down. Most modern DRO systems will retain position memory after shut down but its unwise to rely on that. Disaster potential is high if it does go wrong and you don't notice before starting work.

Clive

Z: spindle moving away from table is the plus (+) direction.

X: spindle moving over to the right of the table is the plus direction – table travels to the left.

Y: spindle moving over to the back of the table (or top when viewed from above) is the plus direction – table travels to the front/down.

These need to be correct for the various DRO functions to work predictably.

Zero can be wherever you want it.

Edited By blowlamp on 03/04/2019 22:29:20

Edited By blowlamp on 03/04/2019 22:33:48

Easy way to do it is look at the old handwheel dials. When they move in a positive direction your DRO should also move in a positive direction for X and Y.

On production work, you may need to put zero on the edge of a set up. You should have a +/- button on the DRO so you can change direction at will.

Go by the right hand handwheel, except when there are two full moons in the month of the wind is in the North-East.

I suspect choosing the handwheel you use most would be the best option.

Neil

Edited By Neil Wyatt on 04/04/2019 10:41:02

.

Hence the 'Ickey Ball' : **LINK**

http://www.wdsltd.co.uk/product/3018/tooling-ball-reference-pin-ickey-balls-with-collar-wds-3505/

MichaelG.