# Uneven bottom of pocket - Z issue? **URL:** \ **Category:** Troubleshooting\ **Created:** [September 23, 2016, 12:46am UTC](https://community.inventables.com/t/uneven-bottom-of-pocket-z-issue/28209 "2016-09-23T00:46:08Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![RichWood](https://yyz1.discourse-cdn.com/flex009/user_avatar/community.inventables.com/richwood/32/87503_2.png) [@RichWood](https://community.inventables.com/u/RichWood)\ **Post date:** [September 23, 2016, 12:46am UTC](https://community.inventables.com/t/uneven-bottom-of-pocket-z-issue/28209/1 "2016-09-23T00:46:09Z")
I’m hoping someone has ran into this issue Yesterday I was having issues with my z axis not wanting to move properly via Easel or UGS. So I took the following steps: 1. Checked free movement of screw - it was too tight 2. Checked V wheels - they were too tight as well I removed my Dewalt and refastened my v-wheels and loosed the delrin nut screws and retightened just past finger tight. After that I could spin my z-axis by hand and it seemed mechanically fine, but it still wouldn’t move properly via UGS - odd grinding noise… next step: electronics! 3. Checked the wiring to make sure nothing came loose - all good 4. Check z axis potentiometer - 1.6 volts I used UGS to send 2.5" up and down and changed the voltage all the way up to 2.4v and back down. It seems to operate smoothly at 1.725v so I left it there. It sounded fine after running it up and down for ~3 minutes. Today I went to engrave the same design again, and I’m getting very odd depth of cut issues. The depth is fine near x/y zero but the far end of the design (~17" from x/y zero) has a very uneven pocket on the bottom. I was using a 0.0625" 2 flute downcut fishtail at 0.03125"doc and 60ipm to a final depth of 0.0625". Check out the attached pictures. One is the clean bottom and the other two are the odd pocket bottoms… After the job finished I resent the job again with 0.0625"doc hoping it would clean it up, and then again with 0.07" doc and 0.07" final depth. Has anyone experienced this or have any suggestions? [![](https://i.imgur.com/ostA31A.jpg) ](https://i.imgur.com/ostA31A.jpg) [![](https://i.imgur.com/KV5k1MG.jpg) ](https://i.imgur.com/KV5k1MG.jpg) [![](https://i.imgur.com/JKoYYMR.jpg) ](https://i.imgur.com/JKoYYMR.jpg) And a good pocket (yes it’s soft wood so it’s not super clean 🙂 [![](https://i.imgur.com/lZrSRD1.jpg) ](https://i.imgur.com/lZrSRD1.jpg) ---
**Author:** ![ErikJanssen](https://avatars.discourse-cdn.com/v4/letter/e/a88e57/32.png) [@ErikJanssen](https://community.inventables.com/u/ErikJanssen)\ **Post date:** [September 23, 2016, 7:48am UTC](https://community.inventables.com/t/uneven-bottom-of-pocket-z-issue/28209/3 "2016-09-23T07:48:07Z")
The side walls of your cut on pitcture 3 show a tooth profile, something must be vibrating. The small differences at the bottom confirm this. Try a lower feedrate and higher rpm setting. The ridge at the picture 2 is strange, looks almost if easel missed that, is it possible that easel thinks you are using a bigger diameter flute than reality? For cutting balsa wood I use these ![](https://cdck-file-uploads-canada1.s3.dualstack.ca-central-1.amazonaws.com/flex009/uploads/inventables/original/3X/5/c/5c71e6604acb83872385b50d8b0e30f31ac9fb33.jpg) It reduces balsa to dust with super clean edges, I let you do the google translation. Sorotec VHM-Fraser Spiralverzahnt 1,5mm. ---
**Author:** ![GaryCaruso](https://yyz1.discourse-cdn.com/flex009/user_avatar/community.inventables.com/garycaruso/32/34629_2.png) [@GaryCaruso](https://community.inventables.com/u/GaryCaruso)\ **Post date:** [September 23, 2016, 3:11pm UTC](https://community.inventables.com/t/uneven-bottom-of-pocket-z-issue/28209/4 "2016-09-23T15:11:13Z")
check your z pulley setscrews, on the motor and the acme, loctite them, make sure the belt is tight but not super tight! also 60ipm is kinda violent on small detail 🙂 ---
**Author:** ![RichWood](https://yyz1.discourse-cdn.com/flex009/user_avatar/community.inventables.com/richwood/32/87503_2.png) [@RichWood](https://community.inventables.com/u/RichWood)\ **Post date:** [September 24, 2016, 12:56am UTC](https://community.inventables.com/t/uneven-bottom-of-pocket-z-issue/28209/5 "2016-09-24T00:56:28Z")
Set screws were all good and the belt is good as well on the z axis. It chews through this soft wood like a champ at 50-60ipm, but I will give it a shot with a more conservative rate and report back. ---
**Author:** ![ToddLumpkin](https://yyz1.discourse-cdn.com/flex009/user_avatar/community.inventables.com/toddlumpkin/32/23598_2.png) [@ToddLumpkin](https://community.inventables.com/u/ToddLumpkin)\ **Post date:** [September 24, 2016, 7:30pm UTC](https://community.inventables.com/t/uneven-bottom-of-pocket-z-issue/28209/6 "2016-09-24T19:30:06Z")
What software are you using? I use Vcarve and have never had any issues. I’ve come to expect some toolmarks but it almost appears to be a toolpath issue. ---
**Author:** ![ToddLumpkin](https://yyz1.discourse-cdn.com/flex009/user_avatar/community.inventables.com/toddlumpkin/32/23598_2.png) [@ToddLumpkin](https://community.inventables.com/u/ToddLumpkin)\ **Post date:** [September 24, 2016, 7:30pm UTC](https://community.inventables.com/t/uneven-bottom-of-pocket-z-issue/28209/7 "2016-09-24T19:30:52Z")
By the way, I’ve never used Easel. ---
**Author:** ![RichWood](https://yyz1.discourse-cdn.com/flex009/user_avatar/community.inventables.com/richwood/32/87503_2.png) [@RichWood](https://community.inventables.com/u/RichWood)\ **Post date:** [October 8, 2016, 1:56pm UTC](https://community.inventables.com/t/uneven-bottom-of-pocket-z-issue/28209/8 "2016-10-08T13:56:13Z")
Final Answer: Belts! The last thing I’d imagine it would be. I’m sure it was a combination of other things I tried (v-wheels, delrin nut, etc), but the very last thing I tried was taking a little slack out of the belts. Afterwards I cut a few test pockets and they’re smooth like they should be. ---
**Author:** ![RobertA\_Rieke](https://yyz1.discourse-cdn.com/flex009/user_avatar/community.inventables.com/roberta_rieke/32/32723_2.png) [@RobertA\_Rieke](https://community.inventables.com/u/RobertA_Rieke)\ **Post date:** [October 8, 2016, 5:29pm UTC](https://community.inventables.com/t/uneven-bottom-of-pocket-z-issue/28209/9 "2016-10-08T17:29:58Z")
Very interesting! Do you have any way of measuring the tension on your belts? I’d be interested in knowing what your before and after tensions were. I measure mine using a fish scale and pulling up an inch in mid-span.