How thick is that area on the part you made and for what gain/loss both in rigidity/weight ?
That area is about 16mm thick. As they sit in the last image the original is 100#
while the machined part is 115#. The original is a beefy part and would probably
function just fine.
The FP4 X axis slide has four t-slots. Most of the tables (except the rigid table)
utilize three of the slots (the third slot down is used for table keys). This particular
table uses up a lot of Z height in its nominal mounting position. I'd like to mount it
lower down than nominal by one slot. To do this I'd like a set of bolts in the lowest
T-slot. This would have been difficult with the previous owners modifications. The machined
part is a slightly modified design as it allows bolts in all t-slot locations.
It's my gut feeling that most of the forces are actually handled by the external portion of the T-nut slot on those flanges. I don't know on the old FP4, but on smaller tables like the 2038 and the 2231, the bolt in the central pivot doesn't get through the flange and isn't attached to the x carriage (wich is a design flaw imho).
So the holding strengh of the central portion of the flange is probably reduced to the limited amount of stock left under the T-slot and actually rather limited.
This is considerably beefier than the smaller tables. The flange where the bolts slots
are located is ~1.4" thick. There is a bolt that goes from the rest of the table into
the pivot pin.
A second question I have is what's the purpose of the bore in the central lower portion of the flange ?
Is it like on smaller tables, where the nut for the side-tilting screw attaches ?
There are three bores in the center of the part-- all are press fit locations. From the top:
-Press fit pin for Pivot
-Press fit bushing for nut (it rotates in the bushing) for above pivot
-Press fit pin that provides end stops for above pivoting
