I have been thinking about the flex in my Z axis and wondering, designing, and pondering solutions. Today I believe I have figured the easiest and best way to handle this problem. Mind you, the flex is very, very slight but I can see the effects when I plunge full depth into 1/2" Baltic Birch at 175 ipm.

The issue, I believe, lies in the extended distance of the single plate of 5/8" aluminum that came with the tramming kit. Prior to the tramming plate the spindle was mounted about 3" higher than it is now and 5/8" closer to the trucks. To me, and I voiced this to Nate when he sent the tramming plate, the cantilevered effect of a nearly 20 lb. spindle hanging that far below and in front of the trucks is just asking for flex.

So my remedy is to move the spindle mount up as far as I can on the tramming plate. This will actually place it about 3/4" higher than it was originally as shipped. I will have to remove the tramming plate, drill and tap new holes, then mount everything back into place and redo the tramming but in the end I think the effort will pay off.

Here are some supporting photos so y'all can see if you concur with my thinking -

Flex shows in the plunge to begin these slots. I can't ramp because the compound bit with its upcut start causes the face veneer to splinter and I can't have that.
Attachment 437910

You can see the flex potential here by how far in front of and below the trucks the spindle hangs -
Attachment 437912

Proposed location (approx.) -
Attachment 437914

Proposed location will still allow access to the tramming bolts -
Attachment 437916

Proposed vs. original vs. current locations -
Attachment 437918

Thoughts?

David