Play in B axis after replacement of milling head

Hi Everybody,

After the replacement of our milling head I noticed that we suddenly have some problems (chatter) with a few tools/operations (boring bars, thread mills) which we didn't have before. The setup (i.e. programs, speed, feeds, material, length of the tools out etc) is EXACTLY the same as before.

Well as the only thing which has changed is the milling head I suspect it to be the cause of it.

I noticed when I position B at 0 and put a dial (right angled to the axis of the milling spindle) on the holder (6" out) and then pull (by hand of course) the holder (down-wards) the dial shows an indication of .0015". I can also read an indication (.0005") if I put the dial on the body of the milling head itself.

Well it looks like to me as there's play in the B axis or so. Of course the B axis was clamped when I tried this. Shouldn't the clamping mechanism prevent this at all? Can somebody tell me if this OK or not or maybe somebody can try this on your machine and tell me what he gets?

Thanks,
Frank

Machine: Integrex 300 IV-ST
Control: Matrix

You mean the knockout of unclamping the tool OR clamping and unclmaping the B-axis OR clamping and unclamping the milling spindle?

I think you mean the unclamping of the tool. You have C6?Tolerance is about less then 0.030mm)

MM

Sounds like he is talking about B-axis clamp, to hold in-position. If so, yes, clamp should hold very rigid, no movement. Let me ask you, does indicator "bounce back" to zero after you stop applying force? Please advise.

i think your test does not prove anything, sorry. the tool holder is flexing, B-axis would as well, even more if you put a longer tool in (longer lever). how is machine geometry after mill spindle replacement?

The B axis is clamped as well the tool (btw if the tool is clamped or not, the dial indicator shows the same results);

The indicator bounces back to zero; Geometry is fine;

@MikiMajk
Nope I'm not talking about the knock out of clamping unclamping tools; I'm talking about the clamping of the B axis it itself

Thanks,
Frank

Check 8 8mm bolts holding B-axis casting down. Make sure they are very tight. See if that improves cutting. I doubt tool chatter is coming from spindle clamp mechanism.

Thanks I will check that

Foo,

If you are asking about B-axis CLAMP and UNCLAMP, then you should frist adjust the coupling. Mazak123 mentonied 8 bolds M12 i think, from side of the milling spindle.
Procedure for mechanical adjust ment is like as follows:
1.Put a test bar inside(testbar is a 150 to 300 mm log bushed bar wich, we use it for adjustments)
2.Put B-axis to 90 degre(vertical)
3.Put 0.02mm dial clock(for rough reading, micron for fine adjustment) somewhere in or near the chuck and clamp it with magnetic stand. Then set the dial indicator at the end or at start of the test bar and move the X axis down or up. During movemnet of the Xaxis, dial indicator will read, and will show, how much and in wich direction is the Baxis angled. What is important when doing this, is that Baxis HAS TO BE CLAMPED(put axis selectior switch at any other axis then B axis).
4. when you find out at wich direction is the Baxies moved and for how much, lossen the 8 bolds from the side of the milling spindle, for one turn and a half. Get a soft hammer, and tap the milling spindle at the apropiate side(clock is still on the test bar), you will see now, for how much the milling spindle moved. The check the alignment again, moving the x axis up and down, and see what is going on with a clock.
5. Once you get aprox. 0.02 at 200mm smoothly tighten the bolds, asteriskly(I tighten them slowwly and finaly tightem them at third round).
6. Now check the aligment again. If not good, then repeat the procedure. You know, tightening is very imporant, it also move the Baxis as well.
7. Then check the UCLAMP AND CLAMP of the Baxis. If not good, set new reference point of the Baxis(its' very simple, see maintenance manual for this)
8. Manualy check the ATC operation by putting some blank tool into the spindle and then test in auto mode.

I hope i didn't forget something,

Good luck,
MM

The B axis is aligned;

Well today we had a guy from Sandvik in and he check the clamping force of the milling spindle with some special tool (unfortunately I wasn't there at this time); What I was told is that the milling spindle apparently only clamps with 30% of the recommended force for Capto tools;

The clamping system for the milling tools is this hydraulic?

For C6 the clamping force should be in range of 33 kN to 38 kN or in Kg from 3t to 3.8t.
The hydraulic only clamps and uclamps the tool, but during machining, the layer springs are holding the tool clamped.
What other did guy from sandvik recommended?

MM