Brother TC-225 Retrofit and Robot integration

andypugh wrote: I have "add spindle homing to LinuxCNC"on my to-do list. But I haven't done it yet.

Basically you need to set index-enable true, then rotate the spindle through index. That should be all that is required.

You can do the first step just by adding a "setp" command in the HAL file. The slightly more complicated part is ensuring that the spindle rotates through index (to reset the encoder counts) before the first orient command.

managed to get 90% of the tool change script to work, needs some timing adjustment and the "spindle homing". Will dive into that next weekend:laugh:

So I would like to connect a potentiometer to linuxcnc to control feed/rapid and spindle override. What's the best way to do this?

Will post an update about the progress of the machine pretty soon.

You can use 7I77 field inputs 1,2,3,4 as analog inputs to read a potentiometer

PCW wrote: You can use 7I77 field inputs 1,2,3,4 as analog inputs to read a potentiometer

Sorry forgot to mention I have the 7i97. There are no analog in pins on there unfortunately

A 7I73 is a possibility if you are not using the sserial port expansion

No eBay APP ID and/or Cert ID defined in Kunena configurationIf you were to swap the potentiometers for MPGs then things would be easier. There are potentiometer-format encoders readily available.
MPG encoders play better with other override sources than potentiometers too.

This sort of thing:

The 7I97 can have up to 4 hardware MPG encoder counters

Ah that's great. Will use mpg's then, thanks for the advice!

Now managed to get tapping working Next weird thing however is that the position error of the spindle index is larger the longer i've run the spindle in velocity mode. So say for example 5 seconds of spindle time is within the orient tollerance with a postion error of 0.4 now running the spindle for say one minute will result in a position error of 2 or so, not within the tollerance. And therefor won't do a toolchange.

Fixed that, turns out the pid settings where not so good