[hatch789]

Hi Guys,

I have 2 older Chevalier VMC's both are 2040 size. The other day I checked my bed for flatness and ran across the whole front then the whole back of the machine. Results were all 4 corners were dead on accept the front right corner was +0.001 (high). That I can live with but here's the kicker, the center of the bed both in front and back are -0.001 (low). Is there any way to fix sag in the middle of the bed?

The 2040MV has 6 leveling (jacking) screws and the 2040VMC-L has 8 leveling screws. I have leveled both machines using the outer 4 jacking screws and they are level across X & Y but my question is regarding the center jacking screws. In the case of the 2040MV machine, there are 2 center screws and on the 2040VMC-L there are 4. I am having a hard time finding information on this but for now I have those center screws all adjusted to about the same tension with gentle pressure.

I read that these center screws are to TRAM the head. Well the other day I Trammed my 2040VMC-L and it was dead on in both X & Y directions. I will tram the other machine soon. Sorry for the odd question but any help you can give is appreciated!

[hatch789]

Figured I would revive this thread since it's a year later and I'm still stumped on a problem with my Chevalier 2040MV machine. The bed shows good across the X axis but when I check the Y axis it's 0.005 low across the entire front of the bed. The bed is level and I've played quite a bit with the jacking screws to no avail. All I can think of is that my column is leaning back ever so slightly off from the 90 degree angle that it should be. Does anyone have any idea what I can do to correct this? This machine has 6 jacking screws and I've read that the 4 in the back (under the column) are for tramming the head in. I have tried to raise the 2 (center) jacking screws at the front of the column in hopes that the main casting would "relax" and allow the column to come slightly forward but so far it hasn't done this yet. I would love to hear some other ideas. I can't seem to find anything in the paper manuals that I have regarding shims or adjustment screws on the column or the head so any help or ideas here are greatly appreciated.

[klxrcr]

How are you checking the table to find it is low in the front? Are you sweeping the table with an indicator in the spindle or is the indicator stationary and you are moving the table?

[hatch789]

The table is pretty much level we have checked it now many times with 2 different machine vices so really the column must be leaning back ever so slightly. The indicator is mounted in the spindle to get this reading. But other than adjusting the jacking screws under the base I don't really know what else I can do and the books do not mention any column adjustment screws anywhere. So I'm hoping they are like any other standard CNC Vertical Mill and in that case how would you adjust the column to come back forward a few thousands? Probably coming forward just a few thousands would reduce that .005 low reading at the front of the table. So to reiterate, it's really not a low table but an "out of 90" column issue.

[machinehop5]

...68-72 degrees controlled jigbore room?

bolted to the foundation pad?