# Problem with a simple toolpath

**URL:** <https://forum.avidcnc.com/t/problem-with-a-simple-toolpath/5927>\
**Category:** General Chat\
**Tags:** ex-controller\
**Created:** [March 17, 2026, 1:25pm UTC](https://forum.avidcnc.com/t/problem-with-a-simple-toolpath/5927 "2026-03-17T13:25:19Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Nicolanti](https://avatars.discourse-cdn.com/v4/letter/n/9dc877/32.png) [@Nicolanti](https://forum.avidcnc.com/u/Nicolanti)\
**Post date:** [March 17, 2026, 1:25pm UTC](https://forum.avidcnc.com/t/problem-with-a-simple-toolpath/5927/1 "2026-03-17T13:25:19Z")

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I have a simple lap joint for joining some 2 x 4’s for a pool platform. Below is a screenshot showing both the 2D view and the toolpath calc screen.

My problem is when I cut this toolpath, it consistently starts the cut 1/4” past where it should be starting. Seems I have to allow the extra 1/4” (one half the diameter of the 1/2” end mill I use) . When I make this allowance it cuts correctly.  
Is this a mistake in something I am doing or possibly an issue elsewhere?

Thanks in advance for any words of wisdom.  
David

 ![image](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/4/413db33f9578eb0101250a73e4d902e7397ac46f.png)

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**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\
**Post date:** [March 17, 2026, 2:58pm UTC](https://forum.avidcnc.com/t/problem-with-a-simple-toolpath/5927/2 "2026-03-17T14:58:56Z")

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It looks like you have your job shifted over 1/4"

 ![image](https://canada1.discourse-cdn.com/flex027/uploads/avidcnc/original/2X/7/7c7687e351b100120c682cba5b3d8e517561c7a1.png)

If this is the “fix” than you need to physically verify your XY zero. You can use the “goto XY zero” button on CNC 12 to take you to your XY zero. Jog down in Z. The CENTER of your bit should be at the corner of work. If it’s not, your XY zero is off.

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**Author:** ![Nicolanti](https://avatars.discourse-cdn.com/v4/letter/n/9dc877/32.png) [@Nicolanti](https://forum.avidcnc.com/u/Nicolanti)\
**Post date:** [March 17, 2026, 3:22pm UTC](https://forum.avidcnc.com/t/problem-with-a-simple-toolpath/5927/3 "2026-03-17T15:22:43Z")

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Eric,

You are right again (you usually are)! I was not referencing the CENTER of the tool….

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**Author:** ![Eric](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/eric/32/3220_2.png) [@Eric](https://forum.avidcnc.com/u/Eric)\
**Post date:** [March 17, 2026, 3:41pm UTC](https://forum.avidcnc.com/t/problem-with-a-simple-toolpath/5927/4 "2026-03-17T15:41:32Z")

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Glad it was an easy fix!