1 Topic by Xandman

  • Xandman
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Topic: Calibration change without any adjustments?

Anyone experienced running calibration more than once without making any adjustments on the knobs but get different values?
My "A" number changes even though I didn't change anything. On one calibration its "+045" then on another it becomes "+105".

Just now I ran my calibration and its +015 +195 +215, I didn't change anything or move it from the last "success". I just turned it off from the last success...ate dinner, came back and ran it again before I start printing...then fails with those numbers sad


This has been bothering me for a while now as calibrating takes a lot of time.

2 Reply by asfgjk (edited by asfgjk 2014-10-14 18:17:35)

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Re: Calibration change without any adjustments?

I have the same problem. I always get differnt values without making any adjustments.
225 / 245 / 275
225 / 155 / 265
225 / 255 / 265
225 / 145 / 265

3 Reply by Jaeg

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Re: Calibration change without any adjustments?

I stopped using the auto calibration quite awhile ago.  I just start a demo print, and when it starts laying down the brim bead, I turn off the printer and use a feeler gauge on all the corners till I can feel it barely making contact.  When I did 3 calibrations in a row and they were off by quite a large margin, I abandoned the use of it as its just to unreliable.

4 Reply by knucklbustr (edited by knucklbustr 2014-10-15 15:43:05)

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Re: Calibration change without any adjustments?

Same here. Makes no sense.
Ill be trying a a continuity test lite using aluminum tape on glass to extruder, see how that goes.
May also use dial indicator, but I dont think precision will make better parts on a non-precision machine.

Also, my prints stick hard. been using a air duster-upside down to freeze the part.
Moving the plater around gotta throw it off.
Ill be replacing calibrating springs w/ either stiffer ones or something else.

DaV1.0  10/13
Repetier FW 0.92, Solidify3D

5 Reply by Chucky14

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Re: Calibration change without any adjustments?

I think I know what's going on.  The heat of the print bed may be throwing something off.  In other words when you heat the metal springs they may be expanding and then when you cooled them they contract the results could end up getting skewed just enough to mess up the calibration.

6 Reply by jjc

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Re: Calibration change without any adjustments?

When the nuts fell off I turned the bed up to try to understand how the supports work.  I didn't spend enough time figuring it out.  It was more important to find the nut that rolled through a crack and disappeared.

But I have a theory:  The springs push out against the nut and the underside of the bed.  If the springs are cheap and don't have ground ends, then they can dig into the plastic (if there isn't a metal plate).  They gouge things and then are resting on chips.  Any little thing can knock the end of the spring off of a burr and change the calibration number.  During Calibration, I notice that the bed finds home several times and every time it does this it pushes the bed down on the springs.

That makes me very suspicious.

Engineer in the Medical Device Industry, used high end 3D printers, but exploring what can be done with inexpensive printers.  Own a Da Vinci 2.0 Duo

7 Reply by carl_m1968

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Re: Calibration change without any adjustments?

jjc wrote:

When the nuts fell off I turned the bed up to try to understand how the supports work.  I didn't spend enough time figuring it out.  It was more important to find the nut that rolled through a crack and disappeared.

But I have a theory:  The springs push out against the nut and the underside of the bed.  If the springs are cheap and don't have ground ends, then they can dig into the plastic (if there isn't a metal plate).  They gouge things and then are resting on chips.  Any little thing can knock the end of the spring off of a burr and change the calibration number.  During Calibration, I notice that the bed finds home several times and every time it does this it pushes the bed down on the springs.

That makes me very suspicious.


I have taken my bed apart.  The springs do have ground ends. The issue is the way contact it made by the bed and the nub. If you do a manual cal as outlined in the sticky you can vsrify with the feeler gauge that it rarely changes.

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

8 Reply by krndragon

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Re: Calibration change without any adjustments?

I've found that cleaning the tip and the plate of the hot bed where it touches VERY thoroughly gives me accurate numbers. A little bit of acetone on the brush given usually does a very good job. Never had a problem since and usually my numbers give the same value. Make sure you watch the tip actually touch the plate and stop. If it is not clean enough, sometimes it'll just keep pushing down for a little bit, thus giving you off numbers. I also just use the calculator someone made online and can usually finish calibration within 5 adjustments(even from a completely messed up starting point).