From de124677b06779a5ac4ade9b4841f2eaed57171d Mon Sep 17 00:00:00 2001 From: Kevin O'Connor Date: Fri, 5 Apr 2019 18:14:45 -0400 Subject: [PATCH] docs: Update BLTouch.md to refer to Probe_Calibrate.md for offset config Signed-off-by: Kevin O'Connor --- docs/BLTouch.md | 89 +++++++------------------------------------------ 1 file changed, 12 insertions(+), 77 deletions(-) diff --git a/docs/BLTouch.md b/docs/BLTouch.md index 76beb2a7..e0bee13a 100644 --- a/docs/BLTouch.md +++ b/docs/BLTouch.md @@ -71,85 +71,20 @@ if it doesn't stop when you touch the pin. If that was successful, do another `G28` but this time let it touch the bed as it should. -Calibrating the BL-Touch -======================== +Calibrating the BL-Touch offsets +================================ -### X/Y Offset +Follow the directions in the [Probe Calibrate](Probe_Calibrate.md) +guide to set the x_offset, y_offset, and z_offset config parameters. -In order to make Klipper work properly you need to tell it in which -relation to the nozzle the probe is exactly located. Lets start with -the `x_offset` and the `y_offset` - -In order to find the proper vertical offset of the probe you need to -know a certain point of your bed. X/Y = 0 may be a good point for -this, any other will do as long as you know it. Find it by lowering -the nozzle next to it using `g0 z0.5`. Create a removable mark on your -bed by i.e. using a non permanent marker. - -Now move the tip of the BL-Touch over that point by jogging there with -the controls in the `control` tab of OctoPrint. Once the BL-Touch is -roughly over the point acquire it using the `GET_POSITION` command. -The difference to your marked point is your `x_offset` and `y_offset` -to configure in the `printer.cfg`. - - -### Z Offset - -1. We start by changing the `z_offset` in the `bltouch` section of the -configuration to 10. This setting is very wrong, but it will make it -possible to move down to the right height using the menus. Run -`RESTART` after changing it to reload the configuration. - -2. Now run `G28`, to home the printer. Take a note of the point where -the pin hits the bed and use the menu to move the nozzle to that -point. Now take a *folded* paper and put it under the nozzle. Move -the nozzle down using the menu, in 0.1mm steps, until it grabs the -paper. It doesn't matter how much it grabs, you are searching for the -higest position that grabs the paper. The nozzle should now be -between 0.1mm and 0.2mm above the printbed. If you wonder why we used -a folded paper, the answer is that the granularity of the movement is -only 0.1mm, or the same as a normal paper thickness, that means that -you could easily move too far and hit the bed. - -3. Now update the `z_offset` to reflect this, by substracting the -current offset (10) by the reading on the printer display. So if it -says 8.2, then `10-8.2` = 1.8 - -4. Restart the printer, issue a `G28`, move to the pin location, then -`G1 Z0`, and verify that it's still grabbing the paper as it was -before. If not, then repeat step 2. and 3. until you are satisfied. - -5. At this point it's a good idea to verify that the offset is close -to 1mm, if not, then you probably want to move the probe up or down to -fix this. You want it to trigger well before the nozzle hits the bed, -so that possible stuck filament or a warped bed doesn't affect any -probing action. But at the same time, you want that the retracted -position is as far above the nozzle as possible, to avoid damage by -touching printed parts. - -6. Now it's time to fine tune with a real print. First make sure that -your flow rate and steps are calibrated properly, so that wrongly -configured flow rates don't affect the calibration. Then slice a one -layer thick object, located close to where you are homing. I recommend -a simple 50x50 mm square. - -7. While the object is printing, use the tune menu to adjust the -"Offset Z", until it looks good. With some practice, it's possible to -find the exact point where it goes from underextrusion to -overextrusion, but some filaments are harder to see than others. Also -notice that the tune command does not have any effect immediately, it -takes a couple of movements until the printer uses the new value. It -might also be hard to see exactly what's happening while it's -printing, so you can adjust for example every cm, and then find the -best setting when the print is done. - -8. Update the `z_offset` configuration again by using subtraction. So -if the display shows that you tuned the z-offset to -0.100, then it's -calculated like this `1.8 -(-0.100) = 1.9`, notice the double minus -sign. - -9. Issue a `RESTART`, and test printing the same thing, this time -without adjusting anything. Perform steps 7-9 until you are happy. +It's a good idea to verify that the Z offset is close to 1mm. If not, +then you probably want to move the probe up or down to fix this. You +want it to trigger well before the nozzle hits the bed, so that +possible stuck filament or a warped bed doesn't affect any probing +action. But at the same time, you want the retracted position to be as +far above the nozzle as possible to avoid it touching printed parts. +If an adjustment is made to the probe position, then rerun the probe +calibration steps. BL-Touch gone bad =================