docs: Update BLTouch.md to refer to Probe_Calibrate.md for offset config

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2019-04-05 18:14:45 -04:00
parent 9f9262cba8
commit de124677b0
1 changed files with 12 additions and 77 deletions

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@ -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 If that was successful, do another `G28` but this time let it touch
the bed as it should. 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 It's a good idea to verify that the Z offset is close to 1mm. If not,
relation to the nozzle the probe is exactly located. Lets start with then you probably want to move the probe up or down to fix this. You
the `x_offset` and the `y_offset` 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
In order to find the proper vertical offset of the probe you need to action. But at the same time, you want the retracted position to be as
know a certain point of your bed. X/Y = 0 may be a good point for far above the nozzle as possible to avoid it touching printed parts.
this, any other will do as long as you know it. Find it by lowering If an adjustment is made to the probe position, then rerun the probe
the nozzle next to it using `g0 z0.5`. Create a removable mark on your calibration steps.
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.
BL-Touch gone bad BL-Touch gone bad
================= =================