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« on: August 23, 2012, 05:58:10 PM »
Below is a pic of the modules and breakouts and an additional board I have made up. This board iis needed for me as the CSMIO/IP-S only has spindle control via one of the Analogue outs and it is 0-10v. That is perfect for VFD's as thats what they take but servo drives usually want a -10 to +10v signal so I needed to invert the signal for opposite rotation. To do this was easy enough, I just used two relays. The other connectors on the board are just distribution points for the 24v. At some point there should be a possibilty to use an unused axis output as a spindle so that would be a better option for me as my drives can accept Step/Dir.
Anyway I have tested out the spindle and it is very linear and the speed closely matches the commanded RPM, its out by about 15rpm but this will be easy to adjust to get closer by altering the volts/rpm setting in my drive.
I have the spindle motor drives buffered encoder outputs feeding the Enc module and this allows Mach to see the RPM. In addition the Enc module is used for lathe threading and unlike the normal setups for Mach the encoder is used rather than just the index, this means that if the spindle slows drastically the axis will, if it speeds the axis will and should lead to very accurate threading even on a machine with an underpowered spindle motor. I have tested this out in simulation by altering the spindle override whilst the threading code is running and the Z axis definitely looks like it is tracking the spindle closely but I suppose I will only know for sure when I ge the machine finished and actually cut some threads.
The encoder usage should also mean that in the future it will be capable of rigid tapping.
I also have the MPG module wired up, I have the MPG connected to the differential inputs (can be used single ended if your MPG is not differential) I also have two rotary switches connected to the MPG module, one is to change the axis that the MPG controls and the other changes the multiplication of the axis. It can be set to x1 x10 x100 for people who use Imperial units or x10 x100 x1000 for people like me who use metric. This is the way most industrial CNC's work and although I am not actually controlling an axis from the MPG at this point it seems smooth when watching the DROs in Mach so hopes are high.
The MPG module also has 2 analogue inputs that can be used for Feed and spindle overrides but I have these connected to the main controller so I didnt use them on the MPG module.
I also have 7 buttons on my front panel which connect va the 24v Inputs on the main controller, I have a few set up so far, Start, Hold, Stop and setting them up is easy, its just the same as you would normally do in Ports and Pins, you just set the port as 10 and the pin to whatever input number it is connected to.
The plugin is very user friendly and has quite a lot of options, one nice thing is that you set the analogue I/O here and it writes direct so you dont have to set anything up in Mach and you dont need a Brain or Macropump for FRO etc. You also tell the Plugin what the spindle encoder count is and it automatically sends the rpm to the Spindle speed DRO so again no setup required in Mach itself.
I will hopefully get a bit more done in the coming week and will post any updates but its looking good so far.
Hood