racear
First off you just have to look through my lathe thread to see how much I knew about servo motors a year or so ago, absolutely nothing. Still dont know a great deal but like you I like to learn
Ok think the best thing is to describe firstly how your present system works. This is a bit oversimplified but it will suffice, your control (computer) sends out a voltage to your servodrives which in turn send out voltage to your motors to make them turn. Your control has feedback from the encoders so it knows where the motors are and so can control the voltage to get the motors to the position it wants to get them to.
Now Mach works differently, it sends out pulses to the drives which will determine how far the drive will tell the motor to go and also at what speed.
So as you can see what you need to make Mach work with your Drives/motors is a device that will accept Step/Dir pulses and convert them to a suitable voltage to send to your drives so that the drives make the motors move. This board also has to accept the feedback from your motors so that it knows your motors got to where they are supposed to be, if not then they will fault out and tell Mach.
I have a had a look at Rutex site and cant find any mention of their converters so looks like they dont sell them any more, in fact I dont know if they ever have, I know they did have them on their site a while back as I saw mention of them but maybe they have never actually had any and were just planning on making them.
As for CNCTeknix, they reportedly were planning on making dedicated converters but again there is no mention on their site but it may be worth an email to them to see if they still have plans to make them.
As mentioned I have the top boards from their Tek10 servo drives, the top boards are the brain part of the drives and as said previously they are supposed to be able to take Step/Dir and turn it into a +- 10v signal and my initial tests seemed to verify that they did that.
Ok next thing is the encoders, you have 1000 counts per rev, now that means it is 4000 pulses per rev as far as Mach is concerned so say for instance your motors need to turn 5 times to move your table 1 inch, that means mach needs to send 20,000 pulses out. If you use the parallel port you should be able to get 45KHz kernel speed, maybe more but I will calculate on that figure. So 45KHz means Mach can send out 45,000 pulses per second (per axis) so 45,000/20,000= 2.25 inches per second max speed which is obviously 2.25 x 60 = 135IPM which will be the max speed you could achieve. If you could get a faster kernel speed reliably then obviously you will get faster rapid speeds (up to the max of your motor capabilities) but whether you will get these kernel speeds will depend on your individual computer.
Ok so say you can only get 45KHz kernel speed from your computer but your motors are capable of going faster and you want faster you would need to get other encoders with a lower count so that the amount of pulses required to move 1 inch is less and thus the 45KHz pulse frequency will move your motors faster. For instance if you got encoders with 500 counts then that would double your rapid speed as it would mean only 10,000 pulses were needed to move 1 inch. This obviously affects your resolution as with 1000 count encoders and 5 turns per inch your theoretical resolution would be 1/20,000= 0.00005 inches but a 500 count encoder would just mean 1/10,000 = 0.0001 which is still pretty good I suppose.
Another option is to use a SmoothStepper motion controller, it takes the place of the parallel port and talks to Mach over USB and is capable of a 4MHz puls rate so no problems there with not being able to get your motors to their max speed
I have SmoothSteppers on all my machines so can highly recommend them.
Ok so how to proceed, best option I would say is the DSPMC as it would take the info from Mach and then send the info to your servo drives to control your motors, problem is its also not the cheapest option.
Next best I think would be if you could get a converter board so Mach sends the signals to it and the board then sends the required voltage to your drives to move your motors.
If you cant get that then the next option would be to replace the drives with something like the Geckos or the Tek10's but as has been said then you would lose speed as they are not capable of the voltage that your motors can use. Rutex do higher voltage/current drives than the others but there have been a lot of bad reports as well as good reports and as I have never tried them I cant say whether they are the way to go or not.
If there is anything you are unclear about just shout, if I know the answer I will do my best to explain or I am sure others will jump in and do so.
Hood