Boss 6 S2 retrofit questions

[jacampb2]

This is a long one guys, so take a stab at whatever part you feel inclined to read. I tried to separate my questions out, and make them logical. I know I haven't detailed my retrofit here, so a little background is as follows: 1982 Bridgeport Series 2 CNC, Boss 6 originally. Converted to PC control, running the original steppers for now, Keling 8078 drivers, CNC4PC C11 BOB, and only running Mach3 for the moment. I am a total CNC newb, so please bear with me if some of these things seem simple.

First, I spent about an hour today trying to figure out what way the table should move for +/-. This may seem rather simple, but it seems to me, that the cnc controller is keeping track of the "controlled point", i.e. the tool. In the case of a fixed head mill, like mine, this means, that as the table moves in the + direction, the tool is actually cutting in the - direction, correct? If I set it up this way it seems ass backwards in the software, but somehow, I managed to get the table to jog what I consider the + direction (standing facing the mill, table moving to the right) when I jog w/ the right arrow, and the dro ticks off -. Sounds like I finally got it right. Then, I run my circular pocket wizard, and the toolpath shown is mirrored from what is actually happening. I have read the manual about 100 times (actually 3x complete), and don't know how it is to be set up, can someone help?

Second, my pocket is undersized by .007" with a 2" pocket, .009" w/ a 3" pocket, similar with square dimensions undersized too. Now, I know how to fix this, but why would it be off? I know my ballscrew pitch, I know my steps per rev, and I know the timing belt reduction ratio. I have a 5tpi ball screw, so .2pitch, 200steps/rev, 2:1(timing reduction), 5 microsteps. I come up with 10000 steps per inch. Is it normal to get it close with math, and have to fine tune it from there?

Third, the C11 BOB is once again giving me hell. I am trying to run the spindle speed via analog reference to the VFD. The VFD supplies a 10Vdc reference, and I have this wired to the BOB analog supply. The board calls out a need for a 12Vdc supply, but the limited documentation specifically states that if your VFD includes a reference output, then the pot on the BOB can be tuned to accommodate a variety of supply voltages. No matter what I do, I can't get more than 8.6 Vdc out of the analog out. My guess is that the BOB really does need a 12Vdc supply. Any thoughts?

And last, the C11 BOB has two on board DC relays and one AC relay. The AC relay and the DC relay share pin 1. I was going to use the AC relay to run the coolant pump. The second DC relay uses input pin #16. I intended to use this one for the start command to the VFD. I cannot assign this pin to the spindle relays in Mach though, it can only use pins 1-6. Any ideas?

Thanks in advance guys.

Jason

[jeep534]

Move this question to the mach3 boards where it would have a larger number of folks to answer your question.

archie =) =) =)

[jacampb2]

I got most of my answers on another board, but thank you for the suggestion.

If anyone else wants to know the answers, I can update them to this thread, just let me know.

Later,
Jason