# Why does an .2mm initial layer measure .4mm +?

**URL:** <https://forum.snapmaker.com/t/why-does-an-2mm-initial-layer-measure-4mm/20959>\
**Category:** Snapmaker 2.0 (3-in-1)\
**Created:** [September 19, 2021, 9:38pm UTC](https://forum.snapmaker.com/t/why-does-an-2mm-initial-layer-measure-4mm/20959 "2021-09-19T21:38:11Z")\
**Posts on this page:** 1\
**Showing post:** 15

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**Author:** ![scyto](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.snapmaker.com/scyto/32/13938_2.png) [@scyto](https://forum.snapmaker.com/u/scyto)\
**Post date:** [September 20, 2021, 1:28am UTC](https://forum.snapmaker.com/t/why-does-an-2mm-initial-layer-measure-4mm/20959/15 "2021-09-20T01:28:03Z")

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> [@brent113](#):
>
> M420 S0

Well in the home position doing that doesn’t change the head position at all.  
However the display coordinates on the touchscreen show a change in Z from 330.01 to 335.16  
So i can confirm the mesh is on at all times if the screen is to be believed.

With the mesh off i still get the same issue.

I enabled backlash compensation (it has been off for all of the tests) which sets the Z backlash to 0.06 based on tests a while back using a dial meter. = Same issue.

checked for any looseness on the x and z rail mount points and head mount points, can’t find any looseness.

So I just took this video… what do you see when looking at it… [https://youtu.be/a4XPAdSCEP4](https://youtu.be/a4XPAdSCEP4) …

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