# Z-Axis tight spot - fails limit switch test

**URL:** <https://community.inventables.com/t/z-axis-tight-spot-fails-limit-switch-test/24692>\
**Category:** X-Carve\
**Created:** [June 7, 2016, 10:04pm UTC](https://community.inventables.com/t/z-axis-tight-spot-fails-limit-switch-test/24692 "2016-06-07T22:04:52Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![AlanSmith1](https://yyz1.discourse-cdn.com/flex009/user_avatar/community.inventables.com/alansmith1/32/84957_2.png) [@AlanSmith1](https://community.inventables.com/u/AlanSmith1)\
**Post date:** [June 7, 2016, 10:04pm UTC](https://community.inventables.com/t/z-axis-tight-spot-fails-limit-switch-test/24692/1 "2016-06-07T22:04:52Z")

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When running my new XC through the limit switch test there is a tight spot with about 20mm of M8 threaded rod left, going up the Z-Axis, before reaching the switch.

It was worse but I adjusted the V-Wheels, motor mounts, pulleys, and lightly oiled the rod. It stops when manually stepping as well. Makes binding sound. I noticed the V-wheel friction is tighter here than further down.

The Dewalt 611 is close to the bracket at this point, but not touching.

It “feels” like the rod might have a slight bend or maybe bad threading - but nothing is visible.

I have to quit working on it right now but will try removing the rod and flipping it end for end in a couple of hours.

I did use a power drill and ran the plastic nut the length of the rod about six times.

Anyone other suggestions? Thanks in advance.

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**Author:** ![JohnChamplain](https://yyz1.discourse-cdn.com/flex009/user_avatar/community.inventables.com/johnchamplain/32/75884_2.png) [@JohnChamplain](https://community.inventables.com/u/JohnChamplain)\
**Post date:** [June 7, 2016, 11:29pm UTC](https://community.inventables.com/t/z-axis-tight-spot-fails-limit-switch-test/24692/3 "2016-06-07T23:29:56Z")

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> [@BobJewell](#):
>
> Over tightening the screws into the delrin nut can cause binding.

So can a misaligned top bearing plate.

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<div class="post-metadata">

**Author:** ![AlanSmith1](https://yyz1.discourse-cdn.com/flex009/user_avatar/community.inventables.com/alansmith1/32/84957_2.png) [@AlanSmith1](https://community.inventables.com/u/AlanSmith1)\
**Post date:** [June 8, 2016, 2:15am UTC](https://community.inventables.com/t/z-axis-tight-spot-fails-limit-switch-test/24692/4 "2016-06-08T02:15:27Z")

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Thanks for the replies!

I loosened and re-tightened both the bearing plate and delrin nut and my XC passed the test.

Went on the do this test carve with 1/4" bit - this is awesome!

 ![](https://canada1.discourse-cdn.com/flex009/uploads/inventables/original/3X/6/e/6e3633c228815bbf30407525c3c775034d3a472f.JPG)