BLTouch nightmare

JoergS5

@Vulrath I have three ideas:

BLtouch is based on hall effect, i.e. uses a magnet to trigger. So the magnetic surface may disturb this trigger too early. A solution may be to use more distance between BLtouch body and surface or an additional magnetic protection. The BLtouch wires are sensitive against disturbance of heater/fan also, so a wire shielding is also an option. Lowering the sensitivitiy of the BLtouch by changing the configuration setting is another possibility.
after power off and on again, steppers start at different positions (up to 4 full steps different), so every expectation about where x,y,z are at startup is not valid. So after startup I would calibrate Z0 and mesh compensation newly. Even XY may be at different places than stored because the endstops may trigger at different positions than last time (so the stored mesh compensation is at a different place than last time). The steppers starting at different positions is especially important if using 2 z steppers, because the x gantry or bed will start unleveled.
I would strip down the procedure to less steps, every complex process can have errors. So I would not use so much store/restores/verifications (or comment out to reuse later when all works ok).

Vulrath

Hey there, Thanks for the reply!

Heres my thoughts,

I agree that there could be interference from the bed now due to the magnetic plate, however I would figure this would cause issues during bed leveling, and homing as well, right? Also I did have this issue a long time agi when i first bought the bltouch, before i put the magnetice plates on. I just dont remember how i fixed it.
this part makes no sense to me, and I guess that could be due to my ignorance, but what would be the point of ever saving a mesh if the initial startup stepper adjustments impacted this?
I can see what your saying about the steppers starting up to 4 full steps different that when they were turned off,(i havent researched it yet, but i believe you) but the 1st thing you have to do before you can level the bed is home all (g28) which should align all steppers. The point of me turning off the machine and turning it back on, is only to test the the saved settings for z offset get loaded in with a power cycle. I want to make sure every time i turn on my machine if i send g1 z0 its going to go to the same place each time. Am I missing something about your point?(probably the case, sorry only been printing for 1 year)
I agree, I will strip down the process some.

JoergS5

@Vulrath about the topic 2:
all measurement has a tolerance: stepper position at startup, endstop triggering (x,y,z), your bed position may be different etc. I meant with the point, you should not trust the state at power on, e.g. stored positions (e.g.: the stored mesh points refer to X Y positions, and they were set with a given endstop measurement). The error may be very small, so it will probably not be the reason, because 2 mm is a much higher error.

When you have stripped down the process, please post config and homeall files. If possible, please make a video (e.g. a 20 second youtube video) of the error behaviour, this would help much to see what could be wrong.

One possible additional reason can be, that you run homeall and then heat up the hotend (M104 doesn't wait for heating up). The homeall should be done when bed and hotend are already heated up.

fcwilt

Hi,

I use the BuildTak FlexPlate System on my two printers.

They both have genuine BLTouch v3.0 devices and they work just fine.

Frederick

Vulrath

@JoergS5 OK, this makes sense to me now. Thank you. I will try to hammer out some of this stuff over the next few days and repost. Thank you for your help with this!

Vulrath

@fcwilt This is good to hear!

Vulrath

@JoergS5 Here are the marlin config files, I'm pretty sure this is the firmware i loaded last.wasnt sure what the homeall file was called , maybe its this HAL.h?
[0_1598381720358_HAL.h](Uploading 100%) [1_1598381656589_Configuration_adv.h](Uploading 100%) [0_1598381656583_Configuration.h](Uploading 100%)

hmm doesnt seem to like these files.

doh gonna have to make smaller vids, ill be back later

Phaedrux

I guess we don't get many .h files uploaded here. You could change the extension to .g and they should upload ok as gcode files. Or change them to .txt.

Vulrath

@Phaedrux Thank you! I'll try that.

Vulrath

@JoergS5 configuration.h file Configurationh.txt

configuration_adv.h file Configuration_advh.txt

videos shortly

Vulrath

@JoergS5 I'm not sure how to make smaller videos. 4mb is a very small limit with todays smart phones and the HD quality of them. or maybe i just dont know how to use it properly. any way to shrink the size drastically , but the video still clear enough to see whats happening?

JoergS5

@Vulrath Maybe you can find an app to make videos with low resolution for youtube. Are you using Android or iPhone, or something other?

I looked into the config files, but I must confess that it's difficult to read if one is used to the Duet config files. Maybe someone can help who knows marlin files.

Are there homing files in marlin or is the procedure you described above a manual process?

Phaedrux

vimeo might be the easiest way to share video.

Vulrath

@JoergS5 I understand, I'm on a Duet forum asking for marlin help, so its ok that your not familiar with it. I have an android. I dont seem to find any homing files, it seems this is a manual process.