I was given a old boss 9. It works but is very out dated. I was wanting to convert it over to mach3. What hardware will I have to purchase to convert it over. I am a machinist not a electrical guy so bare with me.

Boss 9 will have DC servos I think so if the amplifiers are good you could use one of the controllers for Mach that can output +-10v analogue signal for axis control.
There are a few, I am currently using a CSMIO/IP-A from CS-Lab on the Chiron FZ12 VMC I have just retrofitted and I think it is excellent.
The other two controllers I know of that are capable of analogue output are DSPMC from Vital Systems and Kflop/Kanalog combo from Dynamotion.

The other option would be to get new servo drives that are step/dir capable and either use the parallel port or one of the available motion controllers.
Hood

Hood, is there any advantage to using the +-10V analog drivers as opposed to a DG2S16035 drive?  I'm getting poor .001" steps. Sometime the machine finishes moving and then I hear this little thunk and the machine makes an additional .0005" move and all kinds of other things.  My X axis does not do this so much but my Y axis a lot.  I am going to try shielded step and direction cables ( Cat5).  I am running a BP V2XT.  My 110VDC wires are running almost close to my step and dir wires.  Could that be it? Do you kno wof an option for shilded 12AWG power wires? 

   

Blue cat 5 wires are my step and dir wires.  They go an pick up 12VDC at the smaller board and exit to the drivers via the gray wires.  ( Y axis wire is not plugged in).  See any problems in that set up?  Got any shielding suggestions.       

Having the  encoder wires and step/dir wires beside high voltage wires is certainly not a good idea, especially if they are single ended rather than differential. Having said that you should not really be getting that final jump to position, that sounds more like a tuning issue of some sort.
 Hood

OK, by differential, are you talking A, -A, B, -B because that is what I have.  They are also shielded cable to a certain extent, the only mistake I made was to use unshielded plugs and not get the twist as close as I can to the end of the plug.  So you don't think that final jump is caused by noise being picked up by the drivers as a step signal.  This is my second tuning session I have all my axis's down to 5 steps max occured error during a program.  My next PID tuning I will use the official method of bringing gain down  to zero and bring dampening and derivative up till I get oscillation back off and then start increasing gain and the others until all is well.   I have shielded cable on the way.  Should I try my hardest to ground them or is shielding enough? 

     AshB82, its not as simple as you think.  If you plan on sticking with the old pneumatic speed control you off to a good start as those VFDs are really good noise generators.  The 5VDC for TTL logic is very susceptible to noise, Get yourself something like CS Labs parts don't go with the cheap stuff as they only know you till you hadn over the CC # and then all you can do is e mail the vendors and they give you stupid replies to your problems.   

Ok maybe I was misunderstanding with what you were meaning by the additional move. Is this move extra or is it taking the axis to where it is meant to be?
Hood

extra.  axis completes its move and about 1/2- 1.5l second afterwards I hear this faint thunk and there is about a .0001-.0005" move.  Could it be alien X talk in the ethernet wire from the VFD or servo power wires.  I was getting this alot without the spindle running while tuning my servos so I suspect the 110VDC going into the servo drivers. 

Ah ok, well that is different.
You say its Y axis mainly, how easy would it be for you to swap drives around to see if it follows the drive?, if it does then its a drive issue, if it doesnt then possibly a wiring issue.
Hood

By wiring you mean the location of the wire and electrical noise it may be transmitting?  I'll look into swapping dirvers in a few weeks.  I'm so busy right now that I can't afford to chase after .0005".  I'll just have to zero every ten parts I make.