I have been reading about the various thoughts on bracing the X2's column as I have noticed a fair amount of deflection myself - especially when milling steel. I have an idea on what I would like to do to correct it but bear with me as I try to explain it.

The first thing I want to do is mount the base to a piece of plate steel that is 2.5 foot wide, 2 foot deep and 1/2" thick.

Once the base is mounted, I thought about taking a piece of 1/4 wall 3X2 tubing (12" long) and bolting it directly to the column. My original thought was then to weld the tubing directly to the base plate but I changed that somewhat since that would make it impossible for me to angle the head if I ever wanted to. Instead, I plan on welding the tubing to another smaller 1/2" plate that would in turn be bolted to the larger base - This way I could remove the tubing if I ever needed to tilt the head.

Now the tubing itself would have a few access holes cut in the outside so that I could get a bolt in and only bolt the inner wall to the original column.

I have a few very crude drawings that I just did in paint but does anyone think this plan is completely flawed?

I haven't read that much about the deflection issue. Is it primarily side-to-side or front to back?

Front to back from what I have found.

Here are a couple pictures - imagine the tubing flush with the back of the column and welded to the plate underneath it. That plate will then be bolted to the large plate that the mill is on.

I'm sure this has been discussed before, but a search only turned up these photos
http://www.cnczone.com/forums/showpost.php?p=382141&postcount=7

My guess is the largest source of fore/aft flex is the way the column attaches to the base. Ideally the column mount casting would would extend to the back of the base and the base would be slightly longer also.

If my guess is right, the brace idea makes a lot of sense. Building in a slight amount of adjustability (sp?) might be a good plan. Or maybe a bit of shim stock will fix any misalignment. Is there any advantage to retaining the large cupped washer with this design? Probably safe to do away with it.

Coincidently I just bought a 2'x4"x1" chunk of aluminum for a dual-purpose brace/ballscrew-mount. That square tubing will be much stronger.

You could always use a blank angle plate, drill a hole for the pivot bolt, throw away the large washer and put the angle plate in its place. Then you can drill and tap whatever holes you want and you also have an ideal of how square it will be as well. Picture of what I am talking about is below and here is the link http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=948518&PMAKA=418-4325

Here is my column brace. It is fully described in the thread entitled, "took the plunge"

Bill