[Geof]

..... Maybe I should try to put the two extras in there just to bump up pressure a little. I've heard horror storys about people taking out broken washers and shimming the stack with washers, so adding 2 extras couldn't be that bad.

I think you should get an expert opinion on this. This link gives a good explanation of Belleville washers http://en.wikipedia.org/wiki/Belleville_washer

They have to be installed the correct way up because this affects the spring strength. If you put in too many you may run into problems with them bottoming out when the drawbar is pushed down to release the tool.

[nervis1]

Yep you need to measure the washer tube depth and Fadal has a list in the manual stating how many fit in what depth hole.

Reason I ask is that when I replaced mine it was 2 short from the prior owner.

To get a full stack in there one really has to crank on the compression tool and maybe the last owner just could not get it so left a couple out thinking no big deal....or mis counted...

Your count certainly may be correct but since the consequences are so severe if it is not I would double check.

[[email protected]]

Edster,
When does the big test come to find out if the spindle grinding did any good?
I am sure the Z axis position moved. Z axis position moves about 3.4 to one.
If the grinding process removed .003" on the diameter, the gage line would
move approximately .0102". Better example is remove .0010 and Z moves .0034"
I usually tell them to run a part and the first critical Z dimension, measure the
error and move Z home position. If you have a test bar with a known length,
it is easier just to measure and reset home position.
Regards Walt

[Edster]

I did a little milling today, spindle worked great. Much less chattering/buzzing from the tool, especially when the end mill was worn a little. The toolholder did pop while tool changing after milling but I guess that's just from getting wedged in real tight.

I'm not sure why i'd have to reset the home positon. for the tool changer maybe? I reset all my tlo's and fixture offsets. I don't think the tool changer will mind being off .010 though.

[Geof]

...I'm not sure why i'd have to reset the home positon. for the tool changer maybe? I reset all my tlo's and fixture offsets. I don't think the tool changer will mind being off .010 though.

I have been puzzled about the mention of resetting the home position because the new tool position in the spindle only affects the tool changer. I suppose if the machines just goes home to tool change home should be reset but I know some machines have a parameter based on the encoder count that can be adjusted because the tool change position is not exactly at home.

[[email protected]]

Lets see if I can make sense of this.
If you were running a machine with a 100 tools in the tool changer and the programmer goofed up or maybe the machine picked up the wrong tool and
there was a wreck. The spindle would have to be cleaned up. Regrinding the
taper is the quickest most accurate method I know of. The gage line will be
moved some distance and the tools will be shorter. You have two options,
reset home position or change all the tool length offsets in the machine.
If you go the wrong way with one of the offsets, you may need the spindle reground again.
Ofcourse if you go the wrong way with adjusting home position, that may
cause a wreck also but, adjusting home position is only one item, changing all
tool offsets multiplies the chance for errors.
If home position is not adjusted properly, you do not know how deep you
are cutting without trail and error.
If this helps ok but if more explaination is required, I'll try harder..
Regards, Walt.

PS During initial setup of a machine, home position must be determined and
established, grinding the taper changes that dimension. Changing the bearings
depending on the stackup could change home position.
HuFlungDung can tell you after what he went through.....

[[email protected]]

Lets see if I can make sense of this.
If you were running a machine with a 100 tools in the tool changer and the programmer goofed up or maybe the machine picked up the wrong tool and
there was a wreck. The spindle would have to be cleaned up. Regrinding the
taper is the quickest most accurate method I know of. The gage line will be
moved some distance and the tools will be shorter. You have two options,
reset home position or change all the tool length offsets in the machine.
If you go the wrong way with one of the offsets, you may need the spindle reground again.
Ofcourse if you go the wrong way with adjusting home position, that may
cause a wreck also but, adjusting home position is only one item, changing all
tool offsets multiplies the chance for errors.
If home position is not adjusted properly, you do not know how deep you
are cutting without trail and error.
If this helps ok but if more explaination is required, I'll try harder..
Regards, Walt.

PS During initial setup of a machine, home position must be determined and
established, grinding the taper changes that dimension. Changing the bearings
depending on the stackup could change home position.
HuFlungDung can tell you after what he went through.....

[[email protected]]

Sometimes I studddddddder
Sorry bout that
Regards Walt.

[Cartesian-xyz]

Mid 90's Fadal owners, Beware there was much confusssion on the bellevue washer count needed for individual machines after the introduction of the "Locking Drawbar System" I will need to find my notes and post here as I went through a painfull and costly learning process that just should not have happend. Fadal fell down on the job on this one and failed to educated there suppliers. Results were either to low drawbar pressure, or excessfull and resulted in broken washers and then low drawbar pressure.
As was stated in this thread, the bellevue washer pocket depth is critical, coupled with the "Locking Drawber" device or not! I will look for my notes and post here.
Stephen, Cartesian Machine Works

[HuFlungDung]

I'm a long ways from being the expert on Haas yet, I just had my first look around

If the tool seats a wee bit deeper after the grind, it is going to affect the drawbar pull pressure a little bit, but not nearly as bad as omitting a washer or two, because one missing washer is probably going to allow the drawbar to drop (relax) 3/32" or so. After a grind procedure which only removes a couple of thousandths, there is really nothing to adjust with the drawbar spring stack if it was in good shape to begin with. With a force measuring instrument, a person should be able to adjust the washer stack to the nearest whole washer (obviously) to get into the correct pressure range.

When I put the spindle back in the machine, my main concern with the umbrella tool changer was that the tool flange slide straight onto the fingers in the carousel, which it seemed to be so close to perfect (without adjusting it) that I did not fool with it.

The Tool release piston astride the drawbar, I did have to adjust by a single.010 shim.

That is all on a Haas, I don't know how the Fadal might be different.

[[email protected]]

Haas, Fadal, Mazak or Mori, they all have a home position and it has to be maintained
when service work is performed. If Z axis is wrong, make one adjustment, that
corrects the problem and get back to making chips.
Regards Walt