Auto Calibration Standard Deviation

Post Reply
DGBK
Printmaster!
Posts: 106
Joined: Sun May 17, 2015 10:03 pm

Auto Calibration Standard Deviation

Post by DGBK »

I'm curious to see what everyone else gets for standard deviation after auto calibration, especially those of you who can print their entire beds.

I finally got my auto cal working today. Although it is better than the 0.10-0.12 I was getting with a feeler gauge, it is only 0.08. I was hoping for something closer to 0. Since I don't have anything to compare that to, I thought I'd ask.

Thanks for any sharing.

User avatar
Jimustanguitar
ULTIMATE 3D JEDI
Posts: 2631
Joined: Sun Mar 31, 2013 1:35 am
Location: Notre Dame area
Contact:

Re: Auto Calibration Standard Deviation

Post by Jimustanguitar »

The dialogue that pops up after mine runs says that it flattens it out to about .05, although I've seen it up in the 7's as well.

The biggest difference that I've made was measuring the deflection of my hotend at each each probe point with a piece of paper. I can't say that it changed the amount of variation reported by the calibration routine, but it sure did do wonders for my ability to print out to the edges.

dc42
Printmaster!
Posts: 453
Joined: Mon Mar 07, 2016 10:17 am

Re: Auto Calibration Standard Deviation

Post by dc42 »

Mine is currently 0.035mm using 13-point calibration over an area a little smaller than 300mm diameter. I am still getting a slight tilt of the effector when it moves near the Z tower, so I think I still have a small geometrical error.

DGBK
Printmaster!
Posts: 106
Joined: Sun May 17, 2015 10:03 pm

Re: Auto Calibration Standard Deviation

Post by DGBK »

Jimustanguitar wrote:The dialogue that pops up after mine runs says that it flattens it out to about .05, although I've seen it up in the 7's as well.

The biggest difference that I've made was measuring the deflection of my hotend at each each probe point with a piece of paper. I can't say that it changed the amount of variation reported by the calibration routine, but it sure did do wonders for my ability to print out to the edges.


Could you describe that in more detail? I don't know how I'd see deflection. I honestly wouldn't know the hot end had tapped the bed if there wasn't an LED on the FSRs.

User avatar
Jimustanguitar
ULTIMATE 3D JEDI
Posts: 2631
Joined: Sun Mar 31, 2013 1:35 am
Location: Notre Dame area
Contact:

Re: Auto Calibration Standard Deviation

Post by Jimustanguitar »

It was touched on a little bit here: viewtopic.php?f=37&t=10353&p=91689

The official read on how it works is in the RepRap Wiki: http://reprap.org/wiki/Configuring_and_ ... the_hotend

What I did was to run the autocalibration first, and then manually jog the hotend down onto a piece of paper at each calibration point to document what height gave you a good, smooth drag on the piece of paper. Write down those numbers, and add them to your bed.g script as "H values".

Post Reply

Return to “Duet”