In this lesson, we'll look at using spring passes on a small lip feature. After completing this lesson, you'll be able to create an external 2D contour with the spring pass. Let's carry on with the file from our previous example, and now let's go ahead and create a finished contour for the small lip section on the upper portion of the part. Now, as we look at this, if we go into setup one and we simulate this and we jump all the way to the end, then change the transparency on the part, we'll notice that there is still material left above the part that wasn't originally removed, and this is going to cause a problem because it could cause some deflections in the wall. So what we want to do is we want to create an operation that faces the top of the part and removes all that material, because unfortunately, we started with a lot of stock above the part. So to do that, I'm going to go into 2D and select "Face'' for the tool since we've already got a half-inch and mill here, I'm going to use the half-inch and mill. For geometry, I'm not going to make any selections, it'll automatically grab the stock for me. For heights, it's going to go all the way down to the top of the model which is exactly what we want, and for passes inside of here we have some options. We can use a chip thinning option which again will work similar to our adaptive toolpaths, but this changes the way that the tool enters and exits the stock. We also can change the past direction, we can change this step over, we can change a lot of different options. In this case, we're going to be removing a lot of material. So we want to make sure that we do this in multiple depths, and I'm going to set the max step down in this case as 0.08. We're going to have a finishing step down which will be much smaller, and we're going to set the finishing step down to 0.02. We're going to say "Okay'' and allow it to create this operation. You'll notice that based on those parameters it does three main step-downs to remove the material, then it has a smaller step down to finish the part. Once this is done I'm going to drag this all the way up to the top, so that way my first operation is the spacing operation. Now, we're going to select ''Setup one'' go to ''Actions and simulate.'' If we play through this, you can see that it's starting to cut the geometry away and if we speed it up a little bit, we can see that it moves back and forth and it comes back to the start and it removes this and three passes, then it'll come through with the last pass being a much smaller finishing cut all the way down to the top of our part. Then we produce the external contour, and again this is a roughing operation followed by a finishing operation to get down to the final shape. Then we rough out the majority of the pocket, must be this up a little bit. Then we come back in and we use the adaptive tool paths of finished the bottom face of our pocket and then we do some contouring operations to finish the inside. We haven't approached anything inside of this large circular area yet, but right now we're going to focus on removing this outer lip here, and we can always reorient these tool pass at any point in time. So right now, let's go ahead and close this. Let's create a new toolpath, that's going to be a 2D contour. We're going to continue to use tool number eight the quarter-inch flat. This is going to allow us to utilize the most efficient method of changing these tools. We're going to do all of our operations with our half-inch flat and mill first, then when we make the change to our quarter-inch flat end mill will produce all those operations next. So now we're going to create a contour around the outside of the part, and we're going to select this inside lip, and again make sure that the arrow is on the correct side. We don't have to worry about any extensions because this is a complete closed contour. The heights will be based on the selected contour with no adjustments there. The passes is really where we want to focus our attention. We know that we have to take off 0625 from this part. We finished the outside, we've finished the inside and we know from our initial measurements that the thickness of the wall was 0.0625. So knowing that we have to take off as 16, we're going to come in and we're going to use a couple different finishing passes but we really don't need any roughing passes. We're going to do multiple finishing passes, and we're going to repeat the finished pass. We're also going to use leads on all finishing passes, which means that it's going to lead in and lead out using those transitions. We're also going to use a finishing overlap. I'm going to make this equal to the thickness of that lip. In this case, the 065 doesn't necessarily relate to the thickness it just happens to be equal. Really what I want to do here is I want to make sure that the tool doesn't start and stop at the exact same spot, I want it to pass itself for that lead in and lead out, that way there's no deflection in the tool, there's no issue of us leaving a bad surface finish. Now we're going to say ''Okay.'' We're going to take a look at this operation. We're going to again select "Setup one" go to "Simulate.'' I'm going to jump past the first facing operation, jump past the external contour, the two internal pockets, the two internal 2D contours, and then we'll play through the external contour. So there's our first pass. It's going to do a lead again and there's our second pass. Again, it's going to repeat this because we've added a spring pass and notice that the tool does not come away from the part, simply repeats the exact same last operation. If we want to see the toolpath, notice as we turned it on here it shows everything, but we can show just the tail, the last portion of the last toolpath. So here we can see where the lead out is but notice that it doesn't get us all the way to the beginning. So I'm going to go back into the manufacturer workspace. I'm going to select that last contour. What we're going to look at is the overlap between the entry and the exit points. So notice that on the first pass there's an entry and an exit at the same time. If we rotate this around you can see that it's really doing that lead in and lead out the same spot. However, on my final finishing pass it is using that overlap amount that we dictated. So everything looks pretty good here, I'm going to navigate back to a home view. At this point let's think about what we've done so far. We face the top of the part all the way down from the stock to the top edge of this lip, we've done an external 2D contour. The reason we did this is because we had all of the mass of the part inside, this way we knew we weren't going to get any deflection in the external wall, but we still did a couple finishing passes at the bottom to ensure that we were cutting the right stuff. Then we did an adaptive pocket or and adaptive clearing on the inside. We repeated that by going all the way down and finishing the floor, we came back with a 2D contour to finish off the majority of the inside walls and the bottom edges along those paths. Then we repeated the process by finishing the corners on all the pads, and then we did our small step or lip on the outside for a 2D contour. Now, we really need to focus our attention in clearing out some additional geometry in this cylindrical area. But for right now, let's make sure we save our file before moving on to that next step.
