Huge variation in inductive probe trigger height in X direction
nbGU last edited by nbGU
I have a Duet 2 wifi controlling my printer with a 5v inductive probe on a 3mm aluminium heatbed. My trigger height in the centre (X100) is 0.2mm, at X0 the trigger height is 0.036 and X200 0.36
It is a cartesian printer, the bed is level to the best of my ability with feeler gauges on the 4 corners. My X gantry is horizontal measured to 2 decimal places on each Z axis with quality vernier calipers.
What can cause such a variation in trigger height over the width of the bed?
Ive tried with heaters on and heaters off. first layer is overly squashed on one side and not sticking on the other, running mesh bed leveling.
nbGU last edited by
I found that my extruder bracket to the two linear rails (prusa style) has some play In the bearings. My sensor is offset 20mm from my nozzle. My X pulleys are too small so the top of the belt is slightly angled up to the carriage.
At X0 the belt tension is effectively lifting the pinda probe so that the nozzle has to get closer to the bed for the probe to trigger
At X200 the belt tension is effectively pulling the pinda probe down so that it triggers with the nozzle further from the bed.
I will print a new X carriage and use bearings with less play and see if it fixes it.
Well done for diagnosing this! Can often be tricky. As you knew the bed was level physically (as you'd checked with feeler gauges), it can be frustrating when the electronics tell you something different. I'd tend to trust what I can see physically and turn off bed compensation, and just use the probe for homing in the middle.
nbGU last edited by
@droftarts I hadn't thought of just turning off mesh bed compensation... there was me just printing in the middle strip of my bed!
I swapped the bearings out for some with a better fit just by rooting through by bag of spares to find the best ones and greatly improved the issue. Currently designing a new bracket for my Titan Aero to get the Z probe as close to 0 X offset as i can get.