2016 VF2SS Spindle out of square

[MachMachine]

I have a 2016 VF2SS that we noticed starting to create step over lines. We did a quick tram sweep of the head and found it out in X by 0.012" We conducted a level of the machine checking level at three points in Y and got the level perfect. We checked the Z axis square to a precision square block and found the Z axis squareness to read 0.0003" over 8". We also ran an indicator over the table in both and and Y and found the table to be true to the axis with in 0.0004" But when we conduct a tram sweep of the table with an 8" arm and indicator the spindle seems to be out of square by 0.007" TIR. Any idea how this can be corrected and why this has occurred. Machine has been in the same spot since install and we have no history of a crash.

 

[rklopp]

Z trucks worn out or loose on the back of the head?

 

[cwhuffman]

It is entirely possible to knock just the spindle out of alignment, especially with a small bump or crash. I believe the procedure from haas is to get the machine level and then check the geometric alignment, which it appears you have. Once you have done that, you would unbolt the spindle cartridge and insert shims to realign it to the table. We had this done to a TM1P many years ago, and the tech installed plastic shims that were a couple of thou thick, and once torqued down got the spindle within a few tenths of square with the table. I think the spec is .0005 TIR over a 12" circle. We also have a VF2 where I work which has been bumped a few times in its life, and it will leave some steps between passes when facing, but I have noticed that using a smaller tool will not amplify the tram error as much as a 3" facemill would. Of course, the VF2 is out about .0008 TIR over a 12 inch circle.

 

[machineit2]

You do it by shimming the head to get it square. Had a head replacd by Haas one time and that is what they did. I have and old 97 that I just did myself about 6 months ago.

 

[precisionmetal]

MachMachine,

I have a 2005 super mini mill, and what I did was square the head not the table, but to the *movement* of the table.

I clamped an indicator hanging down from the column, then I put a small surface plate on the table sitting on 3 jack screws. I messed with those jack screws until I had the surface plate reading within a tenth or two anywhere, and then I swept the spindle with the indicator on that surface plate. On your VF2, you have a lot more real estate on the table than I do, so I’d consider something like an 18” x 24” surface plate on the jack screws.

Squaring the spindle on my Mini Mill (which is belt drive, 15k model) just required loosening up the belt, then cracking the screws loose that bolt the spindle up into the column, and inserting a shim or shims where required. After everything is tightened back up and the belt tensioned, re-check and then put the cover back on the column.

End result: my machine cuts a nice criss-cross with a face mill traveling in either plus or minus in X or Y. It’s not perfect, but hey… it’s a Haas, not a Hermle.

Your mileage may vary.

PM

 

[MachMachine]

Looks like we probably need to do a head/spindle alignment. Is there any adjustment ability on the head itself. Just trying to understand where something could have moved from when it was originally installed

 

[BGL]

I am struggling with your description but it sounds like what I went thru with my '93 VF 0. I fixed it with very careful leveling of the table and shimming the spindle. I did not have a way of checking my Z squareness but did find a dip in center on Y axis with careful leveling. I had a very nice level and 0.0001" indicator. 1" gageblock and a stout indicator arm. And patience, lots of that.

With the level in center of the table along X I mapped in nine positions. Shifted to Y and repeated. Slow and deliberate It took over two hours. What I found was a dip in the center along Y axis. By carefully tightening the middle two feet I got the dip out. Next I removed the spindle and the ugly shims that were there, cleaned and reassembled. I was careful to torque the bolts equal and in a star pattern. At about a 5" radius I checked the tram of the head. I mapped it in eight positions. I don't recall the values but there was a WTF moment. I did some trig... I lie. I sketched in CAD a vertical line. Drew a circle the bolt pattern diameter at the top another circle at the table distance and approximate diameter of the indicator sweep.

Taking the three points from the sweep data I made three points X,Y,Z to create an as found circle. I chose three bolt holes, front, left and right then made three corresponding points at the ideal circle. Zooming in and making a vertical line thru the point. I got an approximate shim thickness. I made U shaped shims that were as close to what needed to fix. Loosened and inserted two shims where needed. To my surprise and delight I only needed to make two retries. to my dis belief I could not measure 0.0001" at any point. Tried table in nine positions, torqued all bolts and rechecked. Still good, I could not believe it myself.

I faced a 10" square aluminum plate and it was beautiful. I have been all thru the thrust bearings on this old girl, set the backlash parameters.. actually lower than original. She does great work and no evidence of out of square.

So my suggestion is, do a very careful level and tram, might just fix the issue.

 

[BT Fabrication]

need to do this with my machine also, just need to get the 0.006" over 12" with the tram of the head. im thinking its wear in the Z axis making the head nod a little. over 24" its a bit over 0.018"! but corner to corner is flat.