[FastFieros]

Well, I decided with all the backlash threads that come up recently, I wanted to actually check mine. I have had all 1's in there since I had the machine, and that was based on what was already there when I got it. Being that is only .0001, I figured that cannot cause much issue even if it was wrong.

So I get this 6x4 block mounted in the center of the table. I square it up nice and straight on all sides.

I put a dial indicator on one side and zero. Z up and move exactly 6.0 in X, but the indicator is showing that I am .050 off.. I am thinking i would see .050 in my circle pocketing if it was really off .050... So, I try Y on the 4 inch side. Same thing, I zero it and move 4.0 and it is off .050 also.

Ok, so I travel back to my Zero point.. it is prefect on zero. So, I can go from the zero point, travel 6 inch in the X, be .050 off, go back to the zero point and it is zero. Does the exact same thing in Y side at 4.0

Well, I decided to set all the BL to 1=0,0,0 2=0,0,0 ... Just to see if there is a change in the readings. Nope, it is still showing .050 in both directions.

Ok, so I measured the layout/squaring block and it is exactly 6x4 as it should be.

What could be wrong that when I travel in X or Y I am .050 off? I guess since it is .050 in both directions, my circle pocketing comes out ok. I have noticed that when I zero on one side of a part, my pocket is off on the other side, but I just thought maybe the part had a miscast-ed hole in it.

[Excelmachine]

Did you take into account the diameter of the ball on your indicator?

[FastFieros]

Did you take into account the diameter of the ball on your indicator?

dang. that ball is really small, but not a point. I never even thought of that on that tool. Of course if it was my wiggler, I take into account of it for .200

ok,,, I just edit here.

I just went back out there and stand there and look at what you indicated about the tip. The centerline is zero on the edge of the block, and Z is zero. I raise up the indicator, and I move exactly 6.0, and I am Z down back to zero on it, I am putting the same zero centerline on the other side of the block, but it is showing .050 off.

now if I was zero at the CENTER of the block, and I traveled 3.025 to one edge, and 3.025 to the other edge, that would be having to take into account of the ball.

|......................................|
|......................................|
|.)|---------6.0----------|(.|

its the same on both sides as long as I ZERO on one of the sides and not the middle.

[Excelmachine]

Are you using a dial test indicator to try to measure the block? If so, you might gain some insight from this other forum's discussion: Why inconsistent dial test indicator readings - Practical Machinist - Largest Manufacturing Technology Forum on the Web