Practice exercise

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This is a practice exercise, video solution for this practice exercise.

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We want to begin with the supply data set tool pa selection dot F 3D.

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Oftentimes when machining apart,

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picking the right tool path is critical to getting the correct results.

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So in this practice,

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we're gonna be taking a look at three scenarios and we're gonna

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talk about different tool paths and why we might make those selections.

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First.

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When we look at this part,

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we've got three identical open pockets and three identical closed pockets.

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Now there are multiple approaches that we can take for machining this geometry.

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And for the purposes of this practice, we're going to focus only on two D selections.

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The two main go to tool paths are gonna be

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the two D adaptive clearing and the two D pocket.

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While these are going to be the best choices to get started,

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we could also remove this material with something like a two D contour.

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We could even potentially use a facing tool path.

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So to get started, let's first take a look at the closed pockets

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and how A two D adaptive A two D pocket and A two D contour handle these geometries.

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Let's first get started with the two D contour.

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We're going to be using tool number seven, which is preloaded into this data set

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for our geometry.

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On A two D contour, we can select a face or we can select an edge or a contour on a part.

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If we select a face fusion will automatically extrapolate the contour for us.

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From here, we're going to move on to our passes section.

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A two D contour can be used both as a roughing and a finishing tool path,

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which gives it a nice benefit allowing us to create a finishing pass.

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We can do multiple finishing passes.

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If we are trying to use it as a roughing tool path.

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For example, we can have two finishing tool paths with a step over of 0.05.

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We can also alter the finishing feed rate so we can use a higher feed

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rate for roughing and then we can use a slower feed rate for finishing.

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We also have some options for things like finishing overlap,

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preventing the start and stop point on a finishing tool path at the same location.

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We're going to leave these both set to zero for now,

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we can enable roughing tool paths which allows us to create a roughing path.

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In most cases,

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the maximum step over is a value calculated just below the diameter of our tool.

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I'm gonna reduce this a bit to 0.25 and I'm

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going to increase the number of step overs to two.

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I'm gonna leave all the other options as default.

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But notice that we do have some additional things like linking parameters.

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If you are using a two D contour as a roughing and a finishing tool path, generally,

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you would want to ramp in or provide a he

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entry. In

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this case,

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we can turn on ramp in as one of our options

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and then everything else will leave as default and say,

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OK,

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notice that

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instantly we're machining on the incorrect side of the tool path,

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we can fix this a few different ways. But let's double click on the tool path.

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Go back into our contour selection

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and note that currently we're machining the outside of this area.

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This oftentimes happens when we make a face contour selection

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and we may need to reverse the machining direction.

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We do have a drop down here that allows us to select chains,

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face contours and pockets.

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We're gonna use the pocket selection instead of the face contour selection

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and say, OK,

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and then with our face contour, we'll simply hit X to delete it and say, OK,

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when we regenerate the tool path,

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because now it knows it's a pocket and not a face contour,

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it's able to calculate the tool path correctly on the inside.

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So

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this is a tool path that does allow us to

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use both roughing and finishing in the same tool path.

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We can use a ramped entry,

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moving around the part and we can include multiple finishing passes if needed.

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Let's go ahead and move on to the two D pocket.

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A two D pocket is similar to two D contour.

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It's a tool path that can be used both for finishing and roughing operations.

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If we select a pocket

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and move over to our passes. Section

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note that stock to leave is on by default.

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When we're using a two D pocket tool path, generally,

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it thinks that it's going to be a roughing tool path,

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which means it's gonna leave stock behind

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requiring you to go back and create a finishing tool path.

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However, for us, we're gonna turn that off and we're gonna turn on finishing passes,

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we're gonna have two finishing passes just like we did with

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our two D contour and leave all the other settings.

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As is

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note that our maximum step over value is 0.3 we're going to reset this 2.25.

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We also are going to move into our linking

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parameters and note that with our linking parameters,

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it's going to be using a heal

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entry by default,

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but we do have some additional options such as following the profile of our contour,

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which is similar to the ramp option on A two D contour.

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So because of this, I'm going to use the profile option and say, OK,

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to give us a very similar result to our two D contour.

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If I select both tool paths.

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You'll note that they look nearly identical.

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And this is because the two D contour and the two D pocket in this instance,

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are going to provide the same results

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where they begin to differ is when the pocket is larger,

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a two D pocket tool path will machine the bottom

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face of our part as well as the side walls.

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Two D contour is really only looking at the side walls.

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And in this case,

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we're only able to machine the entire floor of the part just based

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on the size of the pocket and the tool that we're using.

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Let's go ahead and take a look at our last option, which is two D adaptive clearing.

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Once again using the same tool,

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making our same selection and moving over to our passes section,

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we're gonna turn off stock to leave.

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But it's important to note that a two D adaptive clearing

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tool path is not generally considered a finishing tool path.

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Generally,

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you would use it only for roughing and you'd come back with either

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a two D pocket or A two D contour to finish your geometry.

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But in all fairness to compare these, let's go ahead and turn that off.

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We don't need to worry about multiple depths.

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We're making a fairly small cut relative to our tool, so we can do this at full depth.

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And in our linking parameters note that it's going

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to be doing a helical ramp by default.

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And there's no option for us to follow the contour.

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And this is because a two D adaptive clearing is using a tral

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motion. It's not based off the profile that we have selected.

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So if we zoom in a little bit and

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we take a look at the motion of the tool,

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the tool is moving around this pocket based on the

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available space using a consistent load or chip thickness,

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that load is going to minimize the wear on the tool preventing us from overloading.

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When we get into things like corners,

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this is something that a two D contour in a two

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D pocket does not really allow us to do efficiently.

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If we go back into our two D adaptive

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and go back to our passes section, we have this optimal load

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right now. 0.2 is the optimal load.

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And if we make this something quite a bit smaller,

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you'll notice that we get a lot more tool motion.

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This means that the engagement of the tool is only 0.05.

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By default,

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the 0.2 is just under the radius value of our tool that's going

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to be the most efficient when we're talking about a half inch tool,

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but not all machines will have the horsepower and not all

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tools will have the geometry to be able to use that.

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So make sure that you pay attention to the tool manufacturer

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specifications before you use a large value for that optimal load.

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So when we're talking about these two options, really,

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when we're two D contour and two D pocket are very similar.

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In this case,

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the two D adaptive is going to be the best option in

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nearly all cases for clearing or roughing a pocket like this.

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It's not going to be perfect in every case. But in most cases, it will,

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let's go ahead and take a look at see how each of these handles open contours.

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So once again, we're gonna start with our two D contour.

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This time, I'm gonna select this bottom edge rather than the bottom face.

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And this is considered an open chain.

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When we have an open chain for a two D contour,

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it is able to extend the start and the end meaning that

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we can come in from the outside and move our way in

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when we take a look at our passes, you'll notice once again,

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we have roughing passes and finishing passes.

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I'm gonna have the roughing pass be fairly large in this case at 0.35.

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And we're gonna try to do two step overs for roughing

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on finishing passes.

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We do want to include multiple finishing passes in this instance.

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And then we're gonna move on to our linking parameters.

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The linking parameters right now are based on a lead in sweep angle.

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If we just simply say, OK, and see what we produce,

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you'll notice that the sweep angle is

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coming horizontally and then curving its way in

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for a two D contour to enter an open side pocket like this.

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Generally,

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what we would want to do is we would want to use an open chain like we have selected

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and we would want to extend the in and the out.

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And let's increase our fragment distance here.

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We're going to make this a bit larger to 0.5.

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This will be the entire tool outside of the part.

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And we'll say, OK,

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now you can see that the tool both starts and finishes well, outside the part,

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the blue lines are gonna be our feed lines.

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The green lines are, are linking into and out of the transitions.

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And then we've got our red and our yellow lines.

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These are gonna be our linking parameters where we jump from one path to

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the other or whether we're transitioning into and out of that tool path.

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So once again, we can

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effectively machine all the geometry.

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However, this is not the most efficient way to do it.

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Let's take a look at what A two D pocket will do. In this case,

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this time again, we're going to select the face.

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It's gonna automatically pull those contours for us

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and it knows that it's open geometry.

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By default

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in the passes section,

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we're gonna turn off stock to leave and enable finishing passes.

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Once again doing two finishing passes

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and in our linking parameters,

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we're gonna leave all of our linking parameters the same and just say, OK,

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and see what the default tool path is.

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Once again, this looks very similar to our two D contour.

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You'll notice that by default with the two D pocket,

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it automatically extended the entry and exit of our

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tool paths without having to add any additional parameters.

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Let's go ahead and do the same thing. Taking a look at two D adaptive

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with two D adaptive clearing with all the same settings,

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disabling stock to leave and saying, OK,

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this also will allow us to enter from the outside of the part.

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However, it's not doing a simple extension of the outside path

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because again, this is really meant to be a roughing tool path.

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One that you would go back with a two D pocket or a two D contour.

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So this allows us once again to use that troyo

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motion,

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keeping a consistent load on the tool.

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When we're talking about using a two D pocket or a two D contour,

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those are going to be using an offset value from our selected edge.

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And that's going to change the tool load as we go around the part,

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as it gets into a corner and it engages more material,

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the tool load is going to go up and as it exits those corners,

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the tool load will go down.

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So how would we machine this geometry in practice?

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Well, once again, generally, what we would do is a two D adaptive tool path.

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However, we would leave stock to leave turned on,

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leaving a small amount of material on both the floor and the wall of the part.

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When we do this, we would come back with something like a two D pocket

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and we would make the same selection

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note that we have a rest machining option.

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But in two D, when we're talking about 2.5 access tool paths,

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rest machining is calculated based on material left behind with

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a tool diameter doesn't really work in our case.

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So what we would want to do is take a look at our passes,

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turn off stock to leave and we would want to do a finishing pass on the outside

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when we select finishing passes and we do one finishing pass and say, OK,

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this will allow us to come in and make that pass on the floor of our part

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and then go back and finish the walls.

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This is much more efficient when we're talking about a closed pocket.

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And if we have a tool that's large enough such as a one

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inch N mill in this case or a three quarter inch end mill,

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we could simply go in with a two D contour and clear everything out as once.

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So whenever you're exploring creating tool paths on a part,

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make sure that you evaluate which tool path you have available,

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the type of tool you're using the geometry that you're cutting

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and whether or not you're making the most efficient use

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of that tool and the removal of the material.