3 Point to Grid Auto bed leveling

[waran14]

Hello All,

I am using the Printrbot simple metal F5. I want to use the GRID leveling instead of the standard 3 point autoleveling.

I would like to update the firmware and flash it. Below is the change I want to make

#define ACCURATE_BED_LEVELING //Activate this <---

#ifdef ACCURATE_BED_LEVELING
// I wouldn't see a reason to go above 3 (=9 probing points on the bed)
#define ACCURATE_BED_LEVELING_POINTS 2
#endif

I went through the flashing procedure for windows and it involved using ATMEL. I am not sure if I should go this route.

Can i compile the firmware in Arduino and Flash it ?

[RetireeJay]

This article from the Printrbottalk Wiki explains that you can use Arduino to compile, but not to flash: http://www.printrbottalk.com/wiki/index ... are_Update The tool for flashing under Windows is Flip - which is a program created by Atmel (the maker of the CPU chip).

Also, there are other compilers. I like PlatformIO: viewtopic.php?f=22&t=10160. But I still use Flip, because PlatformIO hasn't lived up to its promise of uploading the firmware under Windows.

By the way, the "auto leveling" firmware ONLY corrects for a FLAT bed whose plane is not exactly parallel to the X-Y motion of the printhead. It doesn't correct for warp or bending on the bed. There have been many discussions of using more than 3 points, but I think that Mooselake nailed it when he said that even if 9 points allows you a "least squares best fit," the uncertainties are so small with 3-point leveling that using more is just a waste of time.

[waran14]

Thanks Jay. I want to know if my bed is actually bent by probing different points

[Mooselake]

Use a straightedge and look for a gap underneath. Low tech, but effective.

Kirk

[teicher]

Thanks Jay. I want to know if my bed is actually bent by probing different points

You can do that with gcode. Here's a sample that will probe four corners of a 150x150 print surface, just add or adjust x and y coordinates as you see fit.

Code: Select all

G28
G0 X10 Y140
G30
G0 X10 Y10
G30
G0 X70 Y70
G30
G0 X140 Y140
G30
G0 X140 Y10
G30

[bbrown64]

I agree with Moose. Just get a very good metal ruler that is at least 12" long. Test for level using the edge and a flashlight. I am not sure how level the beds are. But I would expect to see no light.

[waran14]

Thanks for the input. I dont have any good square ruler handy. Let me try to borrow. I am kind of positive that there is a bend in my bed.

Btw, can any of you tell me how the rotation matrix is applied by the Z-probe algorithm.
Here are are my G29 outputs
SENT: G29
RECEIVED: Bed x: 10.00 y: 142.40 z: 0.57
RECEIVED: Bed x: 10.00 y: 10.00 z: 0.63
RECEIVED: Bed x: 142.40 y: 10.00 z: 0.81
RECEIVED: ok
RECEIVED: echo:endstops hit: Z:0.81

With Grid leveling on a different printer, I got this
RECEIVED: Bed x: 20.00 y: -20.00 z: 0.29
RECEIVED: Bed x: 190.00 y: -20.00 z: 0.61
RECEIVED: Bed x: 190.00 y: 60.00 z: 0.89
RECEIVED: Bed x: 20.00 y: 60.00 z: 0.63
RECEIVED: Eqn coefficients: a: 0.00 b: 0.00 d: 0.35
RECEIVED: planeNormal x: -0.00 y: -0.00 z: 1.00
RECEIVED: ok
RECEIVED: echo:endstops hit: Z:0.63
endstops hit: Z:0.63

What are Eqn co-efficients and plane normal values ?