Welcome! Log In Create A New Profile

Advanced

Delta Calibration firmware for atmega + ramps 1.4

Posted by VJain 
Delta Calibration firmware for atmega + ramps 1.4
May 10, 2017 09:50PM
Hey everyone,

I have a delta 3d printer running on atmega 2560 + ramps 1.4.
I have achieved good results by manual calibration or by using the amazing escher 3d wizard from dc42.
But I havent had good success with auto calibration so far.

Which Marlin firmware should I go for ? Marlin 1.1.x or Rich cattell's Marlin ?

Has anyone tried the manual probing of marlin 1.1.x to level the bed ?

Please help.
LVD
Re: Delta Calibration firmware for atmega + ramps 1.4
May 10, 2017 10:32PM
What unsuccessful auto calibration FW did you use?

Marlin 1.1.x now includes auto calibration for deltas (G33); you have to enable it in configuration.h; uncomment #define DELTA_AUTO_CALIBRATION.

Edited 2 time(s). Last edit at 05/10/2017 10:35PM by LVD.
Re: Delta Calibration firmware for atmega + ramps 1.4
May 11, 2017 09:45AM
Hi LVD,
Thanks for your amazing work in the AC firmware. I have used the AC firmware provided in the example_configurations of marlin 1.1.x

Here is what I have done:
1) I did not find the correct z probe offset so I kept it 0. Now I run the G33 P6 C0.03 as autocalibration command. The calibration is done in 7-8 iterations.
2) Because I kept the offset 0, after calibration, I manually set the Z-Height.
3) Now as expected it should print a good first layer. But it does not. At one point on bed it prints well, at another point on bed it tries digging into the bed and scrapes.
4) When I manually check the calibration at the base of the towers, it is not equal. At one tower its above the bed, at another tower its into the bed.

5) So i did a M502 - M500 - G33 P6 C0.03.
6) The firmware gives me the same calibration solution again.

Where am I going wrong ? Do I need to find the right z probe offset and do auto level after auto calibration ?

Just for information: Is manual probing not compatible with deltas to use auto leveling ?
LVD
Re: Delta Calibration firmware for atmega + ramps 1.4
May 12, 2017 12:59AM
Auto-level is tilting the bed and is conflicting with auto-calibration; this is like putting the bed on springs in order to calibrate the end-stops. Since you're still using the C0.03 parameter you must be using a pretty old version of the AC-firmware; there has been a bug with the z-offset, but that seems to be solved now. Better get the latest version at [github.com] or if you want the latest of the latest go check out [github.com]. And do not change the calibrated height, but trim it with the z-offset parameter (M851). Manual probing at the towers should give the same results as displayed with verbose level 2 (G33 P2 V2). When probing more points (G33 P6) you should compare results with manual probing the same 36 points.
Re: Delta Calibration firmware for atmega + ramps 1.4
May 12, 2017 07:05AM
Yes, I have uploaded the following firmware: [github.com]

I did a 7x7 point auto-calibration by using the following command: G33 P7 V2
Z-offset value: -0.35
It resulted in a std deviation of 0.008 after 8 iterations.

echo:busy: processing
. c:-0.00 x:+0.01 y:-0.00 z:+0.00
. yz:-0.01 zx:-0.01 xy:+0.00
Iteration : 08 std dev:0.008
.Height:307.52 Ex:-2.22 Ey:+0.00 Ez:-0.53 Radius:154.74
.Tower angle : Tx:-0.02 Ty:-0.91 Tz:+0.00
echo:busy: processing
echo:busy: processing
echo:busy: processing
echo:busy: processing
echo:busy: processing
echo:busy: processing
echo:busy: processing
echo:busy: processing
echo:busy: processing
echo:busy: processing
echo:busy: processing
. c:-0.01 x:+0.02 y:-0.00 z:+0.01
. yz:-0.01 zx:+0.01 xy:+0.00
Calibration OK rolling back.
.Height:307.52 Ex:-2.22 Ey:+0.00 Ez:-0.52 Radius:154.75
.Tower angle : Tx:-0.04 Ty:-0.93 Tz:+0.00
Save with M500 and/or copy to Configuration.h


Then I manually probed 7 of the 49 points (near towers, opposite towers and center)
Here is the result:

Center: -0.55
Tower Z: Near: -0.2 Opposite : -1.3
Tower X: Near: -0.9 Opposite : -0.3
Tower Y: Near: -0.8 Opposite : -0.3

What could possibly create such a huge error ? Can pulley dimensions or belt tolerance cause this ?
I feel the error is possibly in tower Z, because the errors are symmetric in tower X and Y.

Edited 1 time(s). Last edit at 05/12/2017 07:10AM by VJain.
Re: Delta Calibration firmware for atmega + ramps 1.4
May 12, 2017 07:58AM
I manually probed the 7 points and put them in the escher 3d wizard made by dc42.

This is the result shown:
Endstop X -2.3 Y-0.28 Z0
Tower angle: X-0.39 Y-0.32 Z0
Delta Radius 153.73
Height 308.06

So I inserted these values in the firmware and did a M500.

And then I cross-checked and probed the 7 points again. This is the result I got:

Center: 0.00
Tower Z: Near: 0.0 Opposite : -0.05
Tower X: Near: 0.05 Opposite : 0.00
Tower Y: Near: 0.0 Opposite : 0.00

Thats with 100 micron flatness. So what must be going wrong with auto-calibration ? I am very much confused now. Please help.
LVD
Re: Delta Calibration firmware for atmega + ramps 1.4
May 13, 2017 01:28AM
Could you post the output of M420 V
Re: Delta Calibration firmware for atmega + ramps 1.4
May 14, 2017 08:31AM
>>> m420 V
SENDING:M420 V
echo:Bed Leveling Off


It just says bed levelling off every time I send M420 V.

Am I missing something ?
LVD
Re: Delta Calibration firmware for atmega + ramps 1.4
May 14, 2017 10:48AM
Trying to figure out why manual probing gives different results to probing in G33; there was one guy with the same problem, it disappeared when he switched to the latest FW [github.com]
Re: Delta Calibration firmware for atmega + ramps 1.4
May 15, 2017 01:08AM
Uploaded the latest firmware and did auto calibration.
When I cross checked by manually probing, the error is still there.

Please let me know when you find out what causes this error.
Until then I will be using dc42 calculator. But I really want the auto-calibration to work.

Thanks
LVD
Re: Delta Calibration firmware for atmega + ramps 1.4
May 16, 2017 02:57AM
Probe the same points with auto-calibration and the manual check; so use G33 P3 V2 and do your check manually on the same radius that was set with M665 Bx.x on exactly the same points.
Re: Delta Calibration firmware for atmega + ramps 1.4
May 21, 2017 04:04PM
dear lvd
where we can found a manual for this new marlin features?
it s a it hard for non users to understand everything...and if you are not english is a hard way
LVD
Re: Delta Calibration firmware for atmega + ramps 1.4
May 23, 2017 10:18AM
Marlin doc here in the Wiki
Re: Delta Calibration firmware for atmega + ramps 1.4
May 31, 2017 02:27PM
Hi,
I'm struggeling with G33 too,
when I send G33 I get message M665 Bed radius implausible

I'v increased or lowered
#define DELTA_PRINTABLE_RADIUS 130

but I'm always getting M665 Bed radius implausible


If I run Delta Calibration from LCD
I can only run set Delta Hight and X,Y Z separatelly
and not Auto Calibration


I'm stuck
Any advise will be most welcome

Regards
Mario
LVD
Re: Delta Calibration firmware for atmega + ramps 1.4
June 01, 2017 03:32AM
reduce DELTA_CALIBRATION_RADIUS or more easy without recompiling set it with M665 Bxx.x
Re: Delta Calibration firmware for atmega + ramps 1.4
June 01, 2017 05:41AM
LVD Thank You,
I already reduced DELTA_CALIBRATION_RADIUS. to 80
After your replay I reduced ro 60 and now it works

I have one more question regardin G33, do I have to execute any other command
after running G33 or are the new measurements already saved to EEPROM

Regards and thanks

MArio
LVD
Re: Delta Calibration firmware for atmega + ramps 1.4
June 01, 2017 08:00AM
M500
Re: Delta Calibration firmware for atmega + ramps 1.4
July 02, 2017 07:59AM
Hi LVD
Couldn't work out recently.

But found these parameter:
OD of 20 teeth GT2 pulley (measured including the teeth)

1) Pulley 1 - 12.18 mm
2) Pulley 2 - 12.18 mm
3) Pulley 3 - 12.28 mm

Can this affect the calibration process ?
Sorry, only registered users may post in this forum.

Click here to login