The TMC2209 drivers support sensorless homing. Any particular reason we aren’t using it for the x/y axis? Will I run into major problems if I decide to enable it myself instead of using the endstop switches?
The consensus is that it isn’t repeatable enough. And tuning it is a pain. Things like the current limit, and temperature has a big impact.
Microswitches and wires are cheap, so Ryan decided to keep them.
But I know some people have used them. YMMV. I use sensorless on my 3D printer, but if I am off by 1mm, I don’t care.
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I do have the limit switches installed, I’d just rather take them off than cut the pin off the drivers if there wasn’t a major issue with the sensorless homing. It’s just another possible point of failure. Especially because I plan to pull the lowrider off the table when not in use and the location of mainly the y-axis switches will likely cause them to snag and bend or break when being stored away. I guess I’ll just deal with that issue if/when it comes up.
It should be repeatable enough, if you don’t care about repeatable accuracy, likr you will never need to have the same zero point after homing, it works.
I tend to run separate jobs for separate tools, and want my zero points to be the same, as accurately as possible.
The limits on sensorless homing, if the physical stops are good enough aren’t bad, it will stop plus or.minus one full step.
At 100 microsteps/mm, and 16X microstepping, that comes to one full step being 1/6.25mm or 0.16mm this is more than enough to make wood joints not fit, but probably OK for some things.
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Can’t you run multiple jobs on the same piece without re-homing if you don’t cut power?
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Weren’t there some magnetic things for homing that are the bee’s knees?
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Usually, I can, but sometimes pulling the wrench on the collet makes the motors skip. In those cases, I need to re-home.
With all the jumpers on the board for these drivers, you’d think they’d add one to enable/disable the sensorless homing feature instead of requiring a pin removal. Then I could get lowrider up and running with the switches and work on tuning the sensorless in my spare time and fall back to the switches if I run into issues. The way it is now I’m pretty much forced to decide up front or keep a spare set of drivers on hand. Maybe I’ll do that anyways. I do have a printer that I’m migrating from an old rambo to an skr board with TMC2209’s.
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Yup. It’s definitely a bug in the hardware design. You’d think that there would be a version 1.3 with it fixed.