Advanced Search

I wish y'all had been around when I first configured my machine... 20 years ago.

After Tommy's first reply, I did some reading, and realized that since I have X and Y limits, configuring them as homing inputs as well would be trivial. And so it was, plus or minus a "+" or "-", here and there.

I think I never thought there was any point to having a true home, and really, I've gotten by without it until now. I hit the limit switches when jogging reasonably often, but they're soft-mounted, so it's not a big deal.

In any case, I'm fully configured with home+limits on X and Y now, and I have proper soft limits configured, so I'm all set. <Another high five!>

Secondary question: I don't have a Z+ limit switch. My mill is so slow I'd really have to not be paying attention for the carriage to get close to the stepper. A lower limit would be nice, but I really don't understand how that could work. My spindle is a router, so the bit length varies a lot. Is there any way to configure this to work? I see people say that they don't bother with a lower Z limit, and just rely on a soft limit there, but what would you set it to? Is there something about "real" spindles that I don't know? Are the bits always the same length?

I connected the 7i77 to p1 and the 7i78 to p2, i assume this is the correct order.
I've tried to modify the hal so that the z-Axis is the stepper connected to the first interface of the 7i78. The encoder for the z-axis is connected to the 7i77. Is this more or less done correctly? (hal is attached).
Since the 7i78 has no enable signals for the steppers, is it possible to use the enable pin from the spindle, since i am not using this? and how do i need to mod the hal?
Thanks! 

Adding MAX_REVERSE_VELOCITY did the trick for M4 commands. Thanks.

Yes, I do have an abrupt stop with M5 $1, completely ignoring my acceleration parameters. I wonder if there would be any benefit in disabling my stepper motor driver (cheap DM542T) just as the M5 is issued. On one hand, the freewheeling could be more harmful than the coil being energized hard to stop, but on the other hand if the workpiece is delicate, freewheeling for however short of time as it can give it a better chance of survival.

If it's still a bug and 2748 is closed, is there a newer issue open? Does someone have a patch perhaps? Is this my opportunity to dive into the code? 

So it looks like the drive is software-configurable.

I'd suggest going back to basics and connecting the drive to a Windows PC and verifying all the drive settings via the drive tuning software.

SIDE NOTE: make sure the motor's encoder count (1000/4000) matches what the drive is expecting.

Set the dip switches to 'software' (i.e. all ON). The reason is that you can (probably) set the microsteps to a useful number in software and are not limited to one of the 200/800/1600/etc values as with dip switches.

This will allow you to set the microstepping to a value that makes the steps per spindle rev a whole number, making the math for LCNC much easier.
Since LCNC's rotary axes units are set in INI [TRAJ] ANGULAR_UNITS = DEGREES, you need the [JOINT_N] STEP_SCALE to be in steps per degree.

For a 3:1 belt reduction and a 1.8deg motor, if you set the microsteps to 2400/rev (12x microsteps), you will wind up with 20 steps per spindle degree.

If you find that 12x is too fine and the positional accuracy is kinda 'ish', you can go down to 1200/rev (6x) and adjust INI to 10 steps per degree.  That might give the drive a bit more of a chance to hit a particular position rather than somewhere close-ish on either side of the target.  Either way you're still below the encoder's resolution so the drive isn't going to be totally guessing on a position.

And while you're in there, you should adjust the drive's following error tolerance.  I've found that Stepperonline's drives have a following error alarm set extremely high.  As in the motor could be 1/2 a full rotation out of position before it alarms out - not OK for CNC use.