Pocket holes are too small in diameter - CAM output

[joeldbutler]

I'm having an issue with circular pockets not cutting to the correct diameter.

I'm making tasting flight boards out of timber with 5 recessed 62.5mm diameter pockets at 2.5mm deep.

All the other cuts seem to come out accurate: slot, profile cut, but the circular pockets are coming out with a diameter of about 58mm instead of 62.5mm.

I'm using a 3.17mm flat endmill, and that's selected as the tool.

When I go into the sketch or inspect, and double check the measurements, the circular path has the correct 62.5mm diameter.

Anyone know what I'm doing wrong?

Also, I've noticed in the tool settings the "tool diameter offset" is set to "1"

What does that mean?

Screenshots below showing settings, paths etc, and the f3d file is attached

[macmanpb]

Hi joeldbutler,

what are the values in "Stock to leave" section?

[joeldbutler]

I had it set at 0.02mm
I just deleted all the tool paths and redid them, seems to work fine now. I must have ticked something I shouldn't have, but couldn't find what it was.

[HughesTooling]

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@joeldbutler wrote:

I'm having an issue with circular pockets not cutting to the correct diameter.

I'm making tasting flight boards out of timber with 5 recessed 62.5mm diameter pockets at 2.5mm deep.

All the other cuts seem to come out accurate: slot, profile cut, but the circular pockets are coming out with a diameter of about 58mm instead of 62.5mm.

I'm using a 3.17mm flat endmill, and that's selected as the tool.

When I go into the sketch or inspect, and double check the measurements, the circular path has the correct 62.5mm diameter.

Anyone know what I'm doing wrong?

---

 When you say it's coming out about 58mm is that the cut size or the size you see in the G code.

Here's a screen grab of a back plot of one of you pockets.

It shows a radius of 29.613 so 29.613 x 2 + 3.17 = 62.396, you have a stock to leave of 0.05 per side so add that gives 62.496 so the code is pretty much correct!

Here's your stock to leave settings, you should set the smoothing to 0.01 to match your tolerance to get better arc fitting.

Also, I've noticed in the tool settings the "tool diameter offset" is set to "1"

What does that mean?

 Your machine should have a tool library where you set the tool length offsets and diameters so in the g code T1 will load tool number 1 length and diameter offsets,

Mark.

[joeldbutler]

Hi Mark, what I meant was what does tool offset mean?

[HughesTooling · Accepted solution]

It's just the tool number in the library. When you create tools in Fusion they have a number, you can change the number if need to match the tool library in your machine control.

In your file you have 2 tool tool #1 and #2 you need to match those tools in the library on your control, the tool offset is just to call the correct tool for the operation..

Mark

[joeldbutler]

Ah OK thanks Mark

[Dreistein75]

I realize that this post is dated 2016, however if you by chance still read this: I have the very same problem except recalculating the tool paths does not solve it. Have you figured out the reason back in the days?