I've empirically determined that BLTouch (and 3DTouch) hall-effect leveling sensors become erratic after about 16 to 50 hours of printing in an enclosure heated to 50c.
Of five purchased sensors (3 BL-touch, two #D-touch), four are no longer usable:
- One died (could no longer detect it's magnet at all when it deployed and retracted, so a bit more than 'erratic');
- Three lost repeatability, such that repeated back-to-back autohome/Z probe offset measurement cycles yielded about .25mm variation;
My last still-working probe (a BL-Touch) is being restricted to PLA and PETG, and an open enclosure.
Now, this is just anecdotal, and a small sample size, but there is perhaps more than just correlation.
I'm running them on an SKR-1.4 with Marlin 20.5.3, Ender3 in a repurposed CubePro enclosure with the electronics moved outside (except the sensor).
I'm printing nylon at 260c, bed at 110c. I crack the lid with a servo to vent the enclosure when temp goes higher than 5 degrees over setpoint.
Am waiting for inductive sensors.
