Hi Mike
1.Since you will have to strip the mill to carry out the conversion at least in part your question is best split into phases. Firstly check that the Z axis travel is lined up with the column. That is the tool will plunge parallel with the column. I suggest you check this prior to pulling the mill to bits. The adjustment is checked with a DTI mounted on the column and reading on a piece of ground stock (drill stock or silver steel) held in your normal milling collet. I suggest you check this at the extremes of Z axis travel and rotate the rod for each reading and average the results for comparison with the results from the other extremity of Z axis. The adjustment is messy and requires the two parts of the head to be parted and correction shims to be added. This has been well described by Hoss amongst others. If the indicated readings are within 0.001 inch or better leave well alone!
The column also needs to be perpendicular to the table. This adjustment on the X2 mill needs to be checked from time to time as the 90 degree adjustment to the X direction relies on the column bottom joint and is readily adjustable. In the Y direction of travel the adjustment is by shimming the column mounting under the rear or front pair of bolts that hold the column foot to the base. The adjustments in this paragraph can be left to after the CNC conversion.
2.Shim stock is obtainable from many engineering supply houses but those specialising in model engine making often sell packs of shim stock comprising of small sheets of the material. There are other alternatives to buying shim stock. Alli drinks cans are a good source of thin stock as are foil cooking trays. Paper of the hard glossy kind has been used as has stiff plastic foil. My own preference is to cannibalise a cheap set of feeler gauges.
3.Tee slot size should be in the manual that came with the mill the common X2 size is a 12mm slot and a 10 mm thread. Just make sure the bolt does not go right through and pop the cast table. Many commercial 'T' nuts have a thread that binds as the bolt is passed into the nut. These are easy to make and cost a lot particularly if you need a lot. Can you make your own and reuse any other clamping bits you have?
4.No need to change other than to keep axis feed rate in proportion to spindle RPM just as in manual. CNC pundits tend to go as fast as possible to make more cash per hour of machine time.
5.I am the other side of the pond and use online suppliers as they deliver quickly a wide range of stock cut to the size I want. I only have a small band saw and value my fingers being a real coward!
6.May I suggest you check the movement you get measured with a DTI on the table reading the column movement. The X2 generic design has improved a lot over the years and latter machines are a lot more ridgid assuming that the packing grease has been removed from between the mating surfaces of the column base and the tilting pivot and all the bolts are tight. It is a good idea to coat the mating surfaces with a thin rust preventative oil so that they will part cleanly in the future if required. This remark also applies to shimming the head in 1 above
Hope this helps and if others know better perhaps they will jump in. After all there are many ways of skinning this particular cat!
Regards
Pat  |