Issues with Zprobe on Smoothieboard?

I am trying to figure out how to get my BLTouch working on my Smoothieboard and can't seem to figure it out.I have the entire printer working as it should and the BLTouch works just fine so I know the wiring and the config are most likely not the issue.I have been printing for a while with a chinese printer kit.I recently built a new printer from scratch and wanted to use a better board with at the very least better micro stepping.The issue is I have zero experience with anything Marlin/Repetier or any other firmware used on any other boards.The issue I am having is I use G28 to home the machine and it homes perfectly hitting the x,y,andz min endstops.I then attempt to use the G32 command and the extruder triggers the z min endstop then start to travel upward about 20-30mm then stops and starts dropping down to the z min endstop again.The extruder will then hit and trifgger the z min endstop and continue trying to lower the extruder crushing the endstop.

Am I going about performing the g32 command incorrectly.I was under the impression that the g32 would trigger the z min endstop then travel to the first probing point on the bed and start probing?I would really appreciate a little help figuring this out and if someone would be kind enough to walk me through how to set up the BLTouch from start to finish.Thanks

Edited 2 time(s). Last edit at 06/28/2018 04:31AM by siblues.

Anyone have any ideas what this could be?

Are you deploying the BLTouch pin before doing any z-probes such as G32? i.e. running M280 S3.0

Have you confirmed the BLTouch is working and being detected by smoothie before running G32? To test, move z-axis away from the bed (to avoid anymore crashes), run M280 S3.0 to deploy the pin and then run G30 (which will do a single probe) and put something under the bltouch to trigger the pin. If all is well then the z-axis will stop moving down (and i think go back up to where it started). If it doesn't stop when pressing the bltouch pin you have enough time hit the emergency stop/power so it doesn't crash.

Yes I have checked the BLTouch sensor many times it is working perfectly and so is the printer.Ijust can't seem to get the G32 to work.I think I need to use the g codes in a specific order and I am not sure how that is done.I just wired up the printer and sensor and got everything working correctly.I am using endstops on all the axis.This is how i try to use the BLTouch on my printer.I firs manually move the extruder to the center of the bed and issue a G30 after dropping the probe pin.The probe finds the bed height and then I issue a G28 it then homes just fine and triggers all three endstops.I finally issue the g32 and the extruder drops and touches the z min endstop and then starts to raise the extruder and stops then continues to drop down except this time after hitting the endstop it continues trying to go lower and crushes it.

I have a feeling that I need to configure or set up the BLTouch for it to work properly.I just can't figure out how to do this.I can supply a video of what it is doing and my config if you need any more information?

Edited 2 time(s). Last edit at 07/03/2018 05:44AM by siblues.

Attaching the config might help.

From memory (it's been quite a while since i used BLTouch and smoothie), the BLTouch needs to lift immediately after a probe so the pin can go back down for the next probe. When it can't it will go into an error state and and the LED will flash, and the error needs to be cleared before the probe will function correctly. The probe also needs clearance when running the deploy pin command, if it cant go right down also will also go into error.

Since G30 works I'll take a guess at what happening:

If im following, you are homing to z-min with the pin deployed which will put the BLTouch into an error state. Or, your homing, raising the hotend from the bed and deploying the pin and running G32, however, depending on your config, running G32 will first issue a home command before running (which will also cause the same BLTouch issue) - the do home before level can be disabled in the config however you need to make sure you have correctly homed before running G32.

Last time i used smoothie (maybe a year ago), there was no way to configure a deploy/retract script/macro unlike other firmwares so i'm assuming that's still the case.

Some solutions could be:

1) Disable the Do Home before probing in the leveling strategy. Then the sequence would be: G28, raise hotend up to give clearance (i.e. G0 Z10), deploy pin, G32
2) Move endstop to zmax, configure smoothie to home z to max and correctly set the height as in the docs. Sequence: G28, deploy probe, G32. Some printers have a slow z-axis so might not be ideal solution.
3) Its also possible to home without a z-endstop and just use the probe but i'll skip that for now.

Just to be clear I purchased a MKS board and a Smoothie and I am using the MKS as a test rig so I don't destroy a 100+ dollar board.I am very new to all of this and I rather lose 30 bucks than 150 bucks.I just wanted to point that out.I am at my breaking point with these boards and am thinking about buying a Duet wifi in the next few days.I am going to try disabling the do home in the leveling strategy and get back to you.Here is a copy of my current config please let me know if you see anything wrong.Thanks for the help so far.

Smoothie config file


I tried setting the do home to false in the config for the leveling strategy and that didn't work.I also checked to make sure the changes were saved correctly by reformatting the sd and making sure the firmware folder changed to current.

Edited 2 time(s). Last edit at 07/09/2018 02:57AM by siblues.