Notifications
Clear all

How to use "Bed Level Correct" ?  

  RSS
Shree Kumar
(@shree-kumar)
Trusted Member
How to use "Bed Level Correct" ?

Firmware 3.0.6 includes the "Bed Level Correct" setting under Calibration. Four values can be set - left, right, front, rear. Not much info in the manual about using them. Yeah, "advanced feature", so left out of the manual !

Is anybody using this ? Any info on this will be much appreciated.

Before continuing, let me say that my printer is almost well built. XYZ calibration says everything is good. I am looking to tune this further by fixing the bed level.

One logical point to begin this tuning seemed to the output of the Z calibration. I connected the USB cable. Ran Z calibration thrice. Got this on the serial. Bed point 0,0 is considered zero (reference), and the values are w.r.t that:

echo:enqueing "M45 Z"
Bed point 1,0, differences: written -0.00250, read: 0.00000
Bed point 2,0, differences: written 0.22833, read: 0.23000
Bed point 0,1, differences: written -0.18833, read: -0.19000
Bed point 1,1, differences: written -0.30250, read: -0.30000
Bed point 2,1, differences: written -0.20167, read: -0.20000
Bed point 0,2, differences: written -0.61333, read: -0.61000
Bed point 1,2, differences: written -0.95000, read: -0.95000
Bed point 2,2, differences: written -0.89000, read: -0.89000
echo:enqueing "M45 Z"
Bed point 1,0, differences: written -0.00750, read: -0.01000
Bed point 2,0, differences: written 0.20750, read: 0.21000
Bed point 0,1, differences: written -0.20333, read: -0.20000
Bed point 1,1, differences: written -0.32250, read: -0.32000
Bed point 2,1, differences: written -0.22083, read: -0.22000
Bed point 0,2, differences: written -0.63333, read: -0.63000
Bed point 1,2, differences: written -0.96833, read: -0.97000
Bed point 2,2, differences: written -0.91583, read: -0.92000
echo:enqueing "M45 Z"
Bed point 1,0, differences: written -0.05667, read: -0.06000
Bed point 2,0, differences: written 0.11250, read: 0.11000
Bed point 0,1, differences: written -0.17833, read: -0.18000
Bed point 1,1, differences: written -0.35417, read: -0.35000
Bed point 2,1, differences: written -0.30583, read: -0.31000
Bed point 0,2, differences: written -0.60417, read: -0.60000
Bed point 1,2, differences: written -0.98417, read: -0.98000
Bed point 2,2, differences: written -0.99667, read: -1.00000

There is a run to run variation (expected with low cost sensors). However, there is a pattern in the values that hints at the levelling of the bed. The rough simplification of the above values yields


Bed Point (0-2,2) -0.6 -0.9 -0.9
Bed Point (0-2,1) -0.2 -0.3 -0.3
Bed Point (0-2,0) +0.0 +0.0+ 0.2

Clearly, the back of the bed is lower than the front.

I am unable to infer anything else at the moment. Two questions at the top of my mind:
1. Is it possible to derive the bed level values from these values..
2. If yes, how ?

Thanks for any input!
-- Shree

Napsal : 21/08/2016 7:15 am
prusayo
(@prusayo)
Reputable Member
Re: How to use "Bed Level Correct" ?

I use bed level correct since right side was closer to nozzle than left side resulting in more squish. Therefore I made right side +20 to virtually raise nozzle. When I observe first layer at far left and right I can see squish is now even.

Napsal : 21/08/2016 9:01 am
Vojtěch Bubník
(@vojtech-bubnik)
Member Admin
Re: How to use "Bed Level Correct" ?

Shree,

You discovered, that I forgot to disable some of the debugging outputs in the firmware 🙂
We shall fix that in the next firmware release.

> I am unable to infer anything else at the moment. Two questions at the top of my mind:
> 1. Is it possible to derive the bed level values from these values..

Not really.

The bed level correct (the word correction does not fit on the printer display) is supposed to fix tiny differences in the 1st layer squish. If the left side is not squished enough, you shall enter a negative number on the left. If the left side is squished too much, you shall lift the nozzle by entering a positive value on the left etc.

Vojtech

Napsal : 24/08/2016 12:05 am
Shree Kumar
(@shree-kumar)
Trusted Member
Topic starter answered:
Re: How to use "Bed Level Correct" ?

You discovered, that I forgot to disable some of the debugging outputs in the firmware 🙂
We shall fix that in the next firmware release.

I was viewing that as a feature 🙂 I get your point, though. That said, I am not 100% sure if I ran this with my customized firmware...


Not really.

Thanks for that input ! Saves me a good amount of time!

Napsal : 25/08/2016 7:51 am
mike.s4
(@mike-s4)
New Member
Re: How to use "Bed Level Correct" ?

Hello,

Where do you see that code output?

Does that come from Pronterface?

Mike

Napsal : 26/12/2016 4:23 am
Share: