We have a '17-vintage Haas DT1 that has developed a poor finishing problem. The problem first showed up as poor finish and lots of noise with an endmill. Inspection showed a slight looseness of that tool in the spindle. We checked the drawbar force with a force gage and found
ZERO lbs.of force. (My keen, analytical mind said to myself, "Self, this is not good...) I took a sacrificial retention knob and cut approx. .010" from the face that gets tightened against the toolholder. When the test knob was installed on the force gage it read "1150 lbs of force". This is very good according to the range of force the drawbar should be generating. (30-taper, 10K spindle : 920 - 1420 lbs of force.)
Haas tells me that the drawbar assembly is "sweated" together and cannot be disassembled to replace the belleville spring washers. (These have apparently "sacked" and / or broken causing the loss of drawbar force.)
Question: "Is this true?" Haas says the spindle cartridge must be replaced. (i.e."Have any of you Haas end-users disassembled and replaced the bellevilles ?)
I'm asking because they said the same thing about replacing the spindle encoder support bearing. We removed the spindle encoder and replaced the bearing for $12, not $6500 for a new spindle cartridge.
To see if your machine has a serviceable draw bar you will need to provide you HFO or Haas factory with the machines serial number and they will have to check the machines bill of martial to see if the spindle has to be replaced or just the draw bar.
with the spindles that are able to have the draw bars replaced it is truly that, a full replacement assembly is ordered and installed in the spindle cartage and the old unit with the springs and all goes in the scrap bin.
Another thing to watch for is ware from the retention balls on the pull stud "retention knob". These are consumables and will get very deep dimples worn in them from the ball bearings holding the tool in. When they ware it will simulate the affects of a week draw bar and will cause the draw bare to fail quicker