Another HNC-Almost done. A few questions,please?

Hello all.I have found all of the info you all share very helpful and would like to say a big thanks!!
Attached are some pictures of the first of two Hardinge HNC's that are being rebuilt and retro'd with the EMC.All of the original wiring was removed(save the red wires from the mag cabinet to the logic cab) and replaced with new.The original spindle motor was replaced with a 3 hp 3450 rpm Marathon motor and Fuji VFD.The original cone pullys were replaced with a single belt.
The machine has 3000 ppr Aucoders in place of the resolvers and the original Hi-ack's were replaced with AMC 25a20's.I also canned the opto block relays in favor of racks.The computer is a Gigabyte board with a 3GHZ Amd dual core with 4 g of ram.It will be getting a SSHD.It uses the same 5i20 and 7i33 everyones uses and is running 10.04 and EMC 2.4.6.I have a big shop with ample 3 phase,so it's still a 3 phase machine.The pendent box is from a GE1050 Mccm.Yea,the i/o wiring is a rats nest,Im workn on it....The buttons are from the original 550 control and the "Fanuc" MPG is actually made by Nemicon,save yourself some money,buy theirs..
I am fighting some servo bugs.I cant get movement on any axis past 60 ipm with out exceeding the following error,which is set at .05 and .01.The axis are sluggish,but stiff.If jog the x in the neg direction,it causes the z to occilate,to the point of jerking back and forth.
The AMC amps are being run in voltage mode(back emf).Would I be better off in current mode?Any one got any suggestions?
I will have several Fanuc lathe cycles to donate to the cause(all except g70/g71) and Id like to add them to the source.Thanks in advance!!

Can you post a halscope of a jog motion with commanded position and following error plotted?

For voltage/velocity mode you will need some FF1 term

You may have to tune the velocity loop in the drives before attempting to tune EMCs position loop