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Setting up 5i25+7i85+8i20
param.
I'm not sure how I should edit the 8i20.hal file. I installed hall sensor wires to pin 1, 2 and 3 on the 7i84 board.
This is the edited 8i20.hal file
Now when I source the 8i20.hal file, I get this:
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Just delete that line.
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Then you need to use a PID component to close the position loop.
Take a look at the hostmot2 servo sample configs.
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Just out of curiosity, has anyone tried to run an AC induction motor off an 8i20 and the BLDC component like a VFD? looks like cfg=n and the frequency pin might do it.
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interpolating the drive angle between hal edges or setting the 8I20s current loop gain
much lower (or ideally adding an encoder)
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blazini36 wrote: I was able to get my BLCD motor spinning with the post from andypugh in the first page on hall patterns 15 and 34. At any current above 0.5 it gets a a bit wonky.
Is this because it is spinning too fast? If the motor isn't under load (ie isn't connected to the machine) it is possible that things will work better then. (If it's a spindle, then this won't help)
You could try running the servo thread faster, if the machine can handle it,
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Is this because it is spinning too fast? If the motor isn't under load (ie isn't connected to the machine) it is possible that things will work better then. (If it's a spindle, then this won't help)
You could try running the servo thread faster, if the machine can handle it,
It hunts, you can hear it speeding up and slowing down a little bit. It's most noticable when the motor is not connected to the spindle belt, but when it is hooked up to the spindle belt the motor itself seems to smooth out but then you can hear the spindle splines chatter inside the quill. I contribute this to the motor speed increasing and decreasing slightly.
I'm not sure I ever made sense of whether the servo thread rate was taxed or not. I've ran latency tests and whatnot and it generally looks OK, but I'm not sure how to tell if there's actually an issue. I get that standard servo thread error every once in a while, but I've never seen a following error.
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PCW wrote: Yes, as a torque mode drive you need to have some kind of speed control implemented
Simple speed control, or positioning?
I know the hall sensors are used for commutation, but I assumed the BLDC component also used them for speed control. I've only ran the motor with that test file, so there's no PID loop or anything applied
I was waiting on a new NPN hall sensor for the spindle so I can use it with the encoder input. This is only a 4 hole disk but it will feedback speed at least. Is a 16 ppr signal on the other end of a belted (non synchronous) load precise enough?
I saw this coming so I ordered a 1000ppr differential encoder. The motor has a rear output shaft so it's not that big of a deal to turn it into a servo. Unfortunately it's going to be a couple of weeks before I get ahold of the encoder and coupling. This also means I have to ditch the NPN hall sensor for spindle speed.
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