& Construction

Integrated BIM tools, including Revit, AutoCAD, and Civil 3D
& Manufacturing

Professional CAD/CAM tools built on Inventor and AutoCAD
Integrated BIM tools, including Revit, AutoCAD, and Civil 3D
Professional CAD/CAM tools built on Inventor and AutoCAD
Transcript
00:02
In this lesson, we're going to learn about CAM expressions.
00:06
After completing this lesson, you'll be able to: Investigate a CAM expression and edit a CAM expression.
00:14
In Fusion 360, we want to work with our fsae rim front setup.
00:19
We're going to be taking a look at CAM expressions which allow us to create a variable that can help us control some of our parameters.
00:27
There are many different ways in which we can apply these.
00:29
But we're going to take a basic look at how we can apply it to a drilling operation.
00:34
The first thing that I want to do is I want to inspect the holes inside of this design.
00:39
Right now you'll notice that the diameter is 0.177.
00:43
And if we add a secondary unit, you can see that this is 4.5 mm.
00:48
So what we need to do is we need to figure out a way that we can quickly select all of these holes based on that value.
00:55
We're going to start by creating a drilling operation and we're going to select our tool.
00:60
I don't have a drill bit inside of the library that I can use.
01:03
So I need to go into my samples tools.
01:06
I'm going to go into my metric tools.
01:08
I'm going to go into hole making and specifically look at drill bits.
01:13
So we'll select drill and then we need to look for a 4.5 millimeter drill bit.
01:18
We can manually go through these until we get to 4.5 millimeter.
01:22
Or we can use some of our additional filtering options.
01:25
We're going to use aluminum drilling and select.
01:28
Now that we have a drill bit selected, in the geometry section there are many different ways in which we can select a hole.
01:35
We can manually select faces which will allow us to grab the inside of the hole and automatically grab the bottom of the hole.
01:42
We can use selected points which allows us to manually select the upper edge which will automatically grab its center point.
01:48
Or we can use a diameter range.
01:51
When we use the diameter range, it opens up a numeric input box.
01:55
This is similar to any other numeric input box in any of the other toolpaths.
01:60
So things like the stepover or the maximum stepdown value, anytime you see one of these dialog boxes, we can use CAM expressions to help define them.
02:10
One thing that you can do is hold down the Shift key and hover your cursor over the dialogue box.
02:16
And if there's a CAM expression that's driving this, you'll be able to see that expression on the screen.
02:23
So here you can see the value 0.4 is the default.
02:27
The expression is the hole diameter minimum times 2, a system default is the same thing, hole diameter minimum times 2.
02:35
So what we want to do is we want to figure out the range is to look for for the minimum diameter and the maximum diameter.
02:42
Now this case is a little tricky because we're dealing with a metric drill bit, a metric hole,
02:47
and the units inside of our Manufacture workspace are inch.
02:51
But that's okay, we can still deal with that.
02:54
In order to adjust these parameters, we can simply right click and we can edit the expression.
02:59
So right now this comes up at 0.2 and I'm going to go ahead and delete this.
03:04
In order to begin creating an expression, we need to know a little bit about what we want to type.
03:11
If we right click, you'll notice that we don't really have any options to select anything.
03:15
So we need to start typing what we think we should see.
03:19
So I'm going to start typing TOO for tool and then a dialog box pops up, telling us all of the things that we have associated to the tool.
03:28
So I'm going to take a look at the tool diameter.
03:32
So here we have a tool diameter.
03:34
So now I know that if I'm looking for the minimum diameter in this geometry section, my tool diameter is going to be the exact value of my drill bit.
03:44
Now I can do this.
03:45
But if I want to use this for things like pre drilling or if I want to include a range, I want the minimum diameter to match my drill bit.
03:54
I don't want it to have a drill bit that's larger or smaller.
03:58
I want it to be exactly the right size as the minimum.
04:02
However, for the maximum diameter that I want to select, I can go a bit larger than that.
04:08
So if I go to edit expression and once again, I start to type in TOO.
04:14
I started typing TOO. I can go down through my list until I get tool diameter.
04:18
Then if I want to multiply this by a value, let's say that I want it to be at least the tool diameter and an additional 10%.
04:28
So I can multiply that by 1.1.
04:31
I'll select OK.
04:32
And now my expression is looking specifically for holes between 0.177 and 0.194.
04:40
This means that it's not going to grab the large holes in the center that are for the lugs where it bolts the rim to the hub.
04:46
However, it did grab all of the other holes that I have and you can see here that it grabbed them all all the way around the rim.
04:55
Now we need to take a look at the heights. In general, the heights are going based off the hole bottom.
05:01
If we rotate this around to a side view, you can see that the tip is going to the hole bottom.
05:07
If we use drill tip through bottom, it will automatically increase that.
05:12
If we want to go a little bit farther, we can add a positive value to the drill tip through bottom.
05:18
Unlike using the offset at the bottom of a selected contour, when we're using the drill tip through bottom, we want to have a positive value.
05:26
I'm going to have 0.1 and I'm going to say OK.
05:30
So now we've created our drilling operation for all of those holes using that CAM expression.
05:36
And once again, CAM expressions are not restricted to just the hole diameter size.
05:42
They can be used for any of the other operations.
05:45
For example, if we take a look at the 3D contour operation,
05:49
let's go ahead and edit this, go into our Passes section and take a look at the maximum stepdown.
05:56
Right now, the maximum stepdown value is based on a manual number that we entered.
06:02
So right now it's 0.015625.
06:06
The expression is just that value.
06:08
The system default is 0.04.
06:11
But let's say that we want to change this and we want to base it off of a CAM expression, a parameter.
06:16
Well, we can go and edit the expression and right now it's that manual value.
06:21
But what I want to do is I want to take a look at the tool diameter.
06:25
So if I take a look at the tool diameter once again, now we're dealing with an endmill and we're not talking about a drill bit,
06:31
but the tool diameter is going to be a 1/4” ball endmill.
06:35
So if I want the value of this maximum stepdown to be based off of that tool diameter, I can simply apply it to whatever this value is.
06:45
For example, if I want to divide that by 15, I'll say OK, and now we have a value that's 0.01666 repeating.
06:54
So this value is now based on the tool diameter, which means if I decide to change it to a 3/8 ball mill or something smaller,
07:02
if I go down to an 1/8” ball mill, then I'll be able to make sure that this CAM expression is calculating this value based on the tool,
07:10
and not some manual number that I entered.
07:13
If there's a CAM expression that you think that you use all the time for these operations, you can make that the default.
07:20
So for right now, this edit expression is just applied to this one operation in the 3D contour.
07:28
But we can make this expression default for all 3D contour operations.
07:33
If we don't like that, we can always restore it.
07:35
For this example, I'm going to simply say OK because I don't want to set it for all of the operations.
07:40
I only want to set it for this one.
07:43
So this is a quick look at using CAM expressions to quickly find hole diameters based on a hole selection.
07:50
As well as apply it to things like a stepover amount for a 3D contour.
07:55
From here, let's go ahead and save this before we move on.
Video transcript
00:02
In this lesson, we're going to learn about CAM expressions.
00:06
After completing this lesson, you'll be able to: Investigate a CAM expression and edit a CAM expression.
00:14
In Fusion 360, we want to work with our fsae rim front setup.
00:19
We're going to be taking a look at CAM expressions which allow us to create a variable that can help us control some of our parameters.
00:27
There are many different ways in which we can apply these.
00:29
But we're going to take a basic look at how we can apply it to a drilling operation.
00:34
The first thing that I want to do is I want to inspect the holes inside of this design.
00:39
Right now you'll notice that the diameter is 0.177.
00:43
And if we add a secondary unit, you can see that this is 4.5 mm.
00:48
So what we need to do is we need to figure out a way that we can quickly select all of these holes based on that value.
00:55
We're going to start by creating a drilling operation and we're going to select our tool.
00:60
I don't have a drill bit inside of the library that I can use.
01:03
So I need to go into my samples tools.
01:06
I'm going to go into my metric tools.
01:08
I'm going to go into hole making and specifically look at drill bits.
01:13
So we'll select drill and then we need to look for a 4.5 millimeter drill bit.
01:18
We can manually go through these until we get to 4.5 millimeter.
01:22
Or we can use some of our additional filtering options.
01:25
We're going to use aluminum drilling and select.
01:28
Now that we have a drill bit selected, in the geometry section there are many different ways in which we can select a hole.
01:35
We can manually select faces which will allow us to grab the inside of the hole and automatically grab the bottom of the hole.
01:42
We can use selected points which allows us to manually select the upper edge which will automatically grab its center point.
01:48
Or we can use a diameter range.
01:51
When we use the diameter range, it opens up a numeric input box.
01:55
This is similar to any other numeric input box in any of the other toolpaths.
01:60
So things like the stepover or the maximum stepdown value, anytime you see one of these dialog boxes, we can use CAM expressions to help define them.
02:10
One thing that you can do is hold down the Shift key and hover your cursor over the dialogue box.
02:16
And if there's a CAM expression that's driving this, you'll be able to see that expression on the screen.
02:23
So here you can see the value 0.4 is the default.
02:27
The expression is the hole diameter minimum times 2, a system default is the same thing, hole diameter minimum times 2.
02:35
So what we want to do is we want to figure out the range is to look for for the minimum diameter and the maximum diameter.
02:42
Now this case is a little tricky because we're dealing with a metric drill bit, a metric hole,
02:47
and the units inside of our Manufacture workspace are inch.
02:51
But that's okay, we can still deal with that.
02:54
In order to adjust these parameters, we can simply right click and we can edit the expression.
02:59
So right now this comes up at 0.2 and I'm going to go ahead and delete this.
03:04
In order to begin creating an expression, we need to know a little bit about what we want to type.
03:11
If we right click, you'll notice that we don't really have any options to select anything.
03:15
So we need to start typing what we think we should see.
03:19
So I'm going to start typing TOO for tool and then a dialog box pops up, telling us all of the things that we have associated to the tool.
03:28
So I'm going to take a look at the tool diameter.
03:32
So here we have a tool diameter.
03:34
So now I know that if I'm looking for the minimum diameter in this geometry section, my tool diameter is going to be the exact value of my drill bit.
03:44
Now I can do this.
03:45
But if I want to use this for things like pre drilling or if I want to include a range, I want the minimum diameter to match my drill bit.
03:54
I don't want it to have a drill bit that's larger or smaller.
03:58
I want it to be exactly the right size as the minimum.
04:02
However, for the maximum diameter that I want to select, I can go a bit larger than that.
04:08
So if I go to edit expression and once again, I start to type in TOO.
04:14
I started typing TOO. I can go down through my list until I get tool diameter.
04:18
Then if I want to multiply this by a value, let's say that I want it to be at least the tool diameter and an additional 10%.
04:28
So I can multiply that by 1.1.
04:31
I'll select OK.
04:32
And now my expression is looking specifically for holes between 0.177 and 0.194.
04:40
This means that it's not going to grab the large holes in the center that are for the lugs where it bolts the rim to the hub.
04:46
However, it did grab all of the other holes that I have and you can see here that it grabbed them all all the way around the rim.
04:55
Now we need to take a look at the heights. In general, the heights are going based off the hole bottom.
05:01
If we rotate this around to a side view, you can see that the tip is going to the hole bottom.
05:07
If we use drill tip through bottom, it will automatically increase that.
05:12
If we want to go a little bit farther, we can add a positive value to the drill tip through bottom.
05:18
Unlike using the offset at the bottom of a selected contour, when we're using the drill tip through bottom, we want to have a positive value.
05:26
I'm going to have 0.1 and I'm going to say OK.
05:30
So now we've created our drilling operation for all of those holes using that CAM expression.
05:36
And once again, CAM expressions are not restricted to just the hole diameter size.
05:42
They can be used for any of the other operations.
05:45
For example, if we take a look at the 3D contour operation,
05:49
let's go ahead and edit this, go into our Passes section and take a look at the maximum stepdown.
05:56
Right now, the maximum stepdown value is based on a manual number that we entered.
06:02
So right now it's 0.015625.
06:06
The expression is just that value.
06:08
The system default is 0.04.
06:11
But let's say that we want to change this and we want to base it off of a CAM expression, a parameter.
06:16
Well, we can go and edit the expression and right now it's that manual value.
06:21
But what I want to do is I want to take a look at the tool diameter.
06:25
So if I take a look at the tool diameter once again, now we're dealing with an endmill and we're not talking about a drill bit,
06:31
but the tool diameter is going to be a 1/4” ball endmill.
06:35
So if I want the value of this maximum stepdown to be based off of that tool diameter, I can simply apply it to whatever this value is.
06:45
For example, if I want to divide that by 15, I'll say OK, and now we have a value that's 0.01666 repeating.
06:54
So this value is now based on the tool diameter, which means if I decide to change it to a 3/8 ball mill or something smaller,
07:02
if I go down to an 1/8” ball mill, then I'll be able to make sure that this CAM expression is calculating this value based on the tool,
07:10
and not some manual number that I entered.
07:13
If there's a CAM expression that you think that you use all the time for these operations, you can make that the default.
07:20
So for right now, this edit expression is just applied to this one operation in the 3D contour.
07:28
But we can make this expression default for all 3D contour operations.
07:33
If we don't like that, we can always restore it.
07:35
For this example, I'm going to simply say OK because I don't want to set it for all of the operations.
07:40
I only want to set it for this one.
07:43
So this is a quick look at using CAM expressions to quickly find hole diameters based on a hole selection.
07:50
As well as apply it to things like a stepover amount for a 3D contour.
07:55
From here, let's go ahead and save this before we move on.
Step-by-step guide
How to buy
Privacy | Do not sell or share my personal information | Cookie preferences | Report noncompliance | Terms of use | Legal | © 2025 Autodesk Inc. All rights reserved
Sign in to start learning
Sign in for unlimited free access to all learning content.Save your progress
Take assessments
Receive personalized recommendations
May we collect and use your data?
Learn more about the Third Party Services we use and our Privacy Statement.May we collect and use your data to tailor your experience?
Explore the benefits of a customized experience by managing your privacy settings for this site or visit our Privacy Statement to learn more about your options.