Auto_Bed_Leveling: Enhanced G29 command

[DarkAlchemist]

Judge not the actual numbers as my switch requires a lot of pressure to activate so it actually pushes the glass, and pcb, in and repeatability is out the window. This is why I have a new switch on the way (a mouse kind) that is ultra soft touch in comparison. Now do judge the sign of those numbers and considering I let the bed tell me how it wants to go instead of me trying to force it to bend to my will that is the best I can get it with a 4 point Prusa I3 Aluminum build.

As far as homing goes if I hit the middle button that homes X and Y the bed comes full forward (to hit the Y max endstop) and full right (to hit the X max endstop).

[Roxy]

I was mistaken... I just took a look at your Configuration.h file. You have:

// ENDSTOP SETTINGS:
// Sets direction of endstops when homing; 1=MAX, -1=MIN
#define X_HOME_DIR 1
#define Y_HOME_DIR 1
#define Z_HOME_DIR -1

So you are actually Homing to the max position. So, it may be your origin is at the Front Right ???? When you put an .STL file into Slicer and then try to print it, does it get rotated on your bed? Or does it print it in the same orientation that Slicer shows it?

[DarkAlchemist]

Same orientation and that makes me laugh because when I first made this printer I didn't know until I printed something with writing on it.

I was always told my 0,0 origin is front left but not really sure.

[Roxy]

Same orientation and that makes me laugh because when I first made this printer I didn't know until I printed something with writing on it.

I was always told my 0,0 origin is front left but not really sure.

If it prints in the same orientation as what Slicer shows it sitting on the bed... Your origin is at the FRONT_LEFT. I suggest you try re-compiling with that and doing the following:

• Do a G28
• Do a G29 u 3 T
• Do a G28 (To invalidate the correction matrix)
• Lower the nozzle to 1.5 mm above the bed. (because the Topography report you had up above said that was the max things got out of kilter)
• Move the nozzle to each corner and see what the spacing is. The corners in the Topography report that have minus numbers should have a bigger gap than the corners with larger positive numbers. If this is so, you will have proved the Topography report reflects what is really happening on your bed.

I think you should try doing a print! You are going to like watching the Z-Axis correct based upon what the X and Y location are at!

[DarkAlchemist]

Alright so my 0,0 origin really is the lower (front) left then? I will recompile with #define ORIGIN_FRONT_LEFT instead.

+1.61031 +1.36231 +1.08306
+0.32806 +0.17056 --0.11644
--1.26369 --1.56544 --1.60869

I have redone this many times now and the bed is just too unstable (i3 Prusa, imo, has a lousy Y bed layout among other things) so I will redo all of this after I get my switches and try and print a new arm for the new switch. If the new switch is still too stiff I have no idea what to do from there.

[Roxy]

These switches work just fine. They don't press very hard. They are not super high quality, but they work fine:

http://www.ebay.com/itm/New-Micro-Ro...item4ad2b6aa55

And this thread has the .STL and source code for a probe leg to hold the switch. And the source code has a module to generate the enclosure to hold the servo. If you feel like messing with it, you can have everything pretty clean.

Incidently, I have an i3 kit. I did change one thing about the bed. It originally had 3 linear bearings holding it to the rails. I added one (to the side that only had one) and spread the other two further apart for better support. Even before I added the extra bearing, the auto bed leveling worked well, but now it works really good.

http://3dprintboard.com/showthread.php?2810-Inexpensive-Auto_Bed_Leveling-compatible-extruder&highlight=ebay+micro

[DarkAlchemist]

Yeah, once I get my cnc router I plan on grabbing some 1/4" aluminum and cutting my own with 4 bearings. I asked why it had 3 instead of 4 and I was told it was due to friction and force.

This is the switch I have coming - http://www.ebay.com/itm/321280976852...%3AMEBIDX%3AIT

[DarkAlchemist]

Alright, I printed a new arm and installed the new switch and night and day difference. No more flexing of the bed to make the switch trigger but I am not 100% sure I have the X and Y values exactly right and my Z said 2.10 difference but the count was 2.15 (seems my Z difference is a half a step off). I am not exactly sure how to tweak these as eyeballing it is probably a little off for the probe and hotend differences at least in the X and Y direction.

>>> g28
SENDING:G28
SENDING:G29 U 2 T
Eqn coefficients: a: -0.00 b: -0.00 d: -3.60
Correct +.14 with one clockwise turn.

Bed Height Topography:
+0.17388 --0.23412
+0.09687 --0.03662

planeNormal x: 0.00 y: 0.00 z: 1.00

Bed Level Correction Matrix:
0.999999 0.000000 -0.001661
0.000000 1.000000 -0.000370
0.001661 0.000370 0.999999
echo:endstops hit: X:189.09 Y:173.03 Z:-4.01
>>> g28
SENDING:G28
>>> g29 u 2 T
SENDING:G29 U 2 T
Eqn coefficients: a: -0.00 b: -0.00 d: -3.58
Correct +.14 with one clockwise turn.

Bed Height Topography:
+0.17369 --0.23056
+0.09144 --0.03456

planeNormal x: 0.00 y: 0.00 z: 1.00

Bed Level Correction Matrix:
0.999999 0.000000 -0.001627
0.000000 1.000000 -0.000349
0.001627 0.000349 0.999999
echo:endstops hit: X:189.07 Y:172.99 Z:-3.98

I see way better repeatability since the bed did not flex when it was gently touched for its probings.

[Roxy]

Your 'Repeatability' is very good. The verbose print out says it knows Z is at -.76 when the probe fires. What numbers are you telling it to retract the Z by after and between probing. It doesn't make sense the final position varies. But my guess is the retraction numbers are factoring into this.

Did you figure out which corner your origin is in? Here is an easy way to do that. First, tell PronterFace to turn on the nozzle heat and let that settle. (It may be possible you don't have to do this... But this will work...) Do a G28 and let that finish. Then do a G1 X5.0 Y5.0 and see which corner it goes to.
That will be the origin.

[DarkAlchemist]

G! X5.0 Y5.0 put it in the front left corner.

Between, and Before Probings is at 4 and 4.