# how to figure radius for angle cut on cnc milling machine

Well its been a while since i’ve been on this site, but as one of your visitor I have some question to ask. I was doing research on line with the keyword of “how to figure radius for angle cut on cnc milling machine“.

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## 5.0+- This is the size of the circle that the cutter will cut when it’s in a full down position

The cutting head has 3 positions: up, middle and down. The up position is where the cutting head is raised all the way off of the work so that it’s not touching anything. This is done by using a motor to raise the cutting head with a threaded shaft and nut combination.

The middle position is where the cutting head is sitting on top of the material but not pressed down. Again, this is done by using a motor to raise or lower the cutting head with a threaded shaft and nut combination. The middle position also puts tension on a spring that helps hold the cutter down when it’s in its final location, which is at its lowest point…down!

When you are ready to cut your parts, you will move the cutting head down into this final position and begin your cutout process. You can do this in two ways:

One way would be to use a foot pedal (or hand switch) that will turn on and off your machine during each pass of your CNC router program.

## 6.0+- This is how far you want the center of your cutter to be up from the lowest point on the radius

Let’s say you want to round the edges off of a rectangular piece of wood. You could use a router, but we’re talking about doing this with a hand tool. So you get your trusty chisel and start chopping away at the corners. But wait! If you remove wood from the high spots of the corner, it won’t be flat anymore . . . so you have to remove wood from everywhere first, then go back and ease those corners. A spokeshave is perfect for this task.

Now let’s make that example more difficult. You’re making a table top with legs that are attached to the underside of the top with mortises and tenons. You can’t use your spokeshave in there — but you can probably use chisels (if you’ve got really good ones). The secret is to remove all the waste between the mortise and tenon before working on any of the shoulders or cheeks.

Lastly, let’s look at a super-difficult example: the dovetail joint. It’s been said that dovetails are difficult because if you make a mistake, there’s no way to fix it except by starting over. And I’ve done that many times myself!

## 7.0+- This is how far you want to back off that angle to get the right radius and put it in the work area

It can be difficult to accurately measure angles with a protractor, but there’s an easy way to get the precise angle you need for any project.

Step 1: Cut your piece of wood or plastic to the size you want (the larger the better).

Step 2: Draw a line down the center of one side. This will give you two equal triangles.

Step 3: Mark off your desired angle on one triangle (e.g., 45 degrees). Mark it off from both ends so they meet in the middle of the line you drew down the center of your piece of wood or plastic.

Step 4: Use a straightedge (such as a ruler) to connect the marks you made in step 3.

Step 5: Draw a line parallel to this new line at exactly half its length (for example, if you made a 45-degree angle, draw another line at 22.5 degrees). This new line is your angle.

Step 6: Repeat steps 3 and 4 on the other triangle, but don’t mark any more lines! Instead, just repeat steps 5 and 6 until you have created as many angles as needed for your project.

## 8.0+- This is how tall your work piece is and you are NOT going above this height or if you do you must use a smaller pitch for your cutter so as not to run into anything

For the gcode this tool generates, your Work Coordinate System (WCS) needs to be set to the lower left corner of your material. See the section below on changing your WCS.

The tool is pre-configured to use a full sheet of 1/8″ acrylic as a base material and it assumes that you are cutting a large circle in the middle of your material (in other words, it assumes that there will be an extra 1/2″ all around before starting the cut).

If you want to cut something smaller than 1/2″, you will need to adjust the “Adjustment” boxes in the dialog. If you want to cut something larger than 8.0″ tall, you will need to adjust the “Max Z” box in the dialog.

## 9.0+- This is what we need to find out and is equal to A squared minus B squared plus C squared

The best number in the world is 9.0+- 0.1. It’s the best because it’s not too big, not too small, and it has a neat little circle right at the top (it can also mean a lot of other things but these are all quite technical).

9.0+- 0.1 is also excellent because it’s part of a more complex formula:

9.0+- 0.1 = A squared minus B squared plus C squared

Where A, B, C are all smaller than 1 (A = 1 +- 0.2, B = 1 +- 0.3 and C = 1 +- 0.4)

This formula is neat because the sum of all three numbers multiplied by their errors will always equal 9, no matter what numbers are used (we can have negative or positive numbers as long as they’re less than one). So if you know A and B, then you’ll always get 9 when multiplying them together! That’s pretty neat eh? But wait…what about C? Well there isn’t any such thing as “C”, so we’re left with an error of zero which means that any number from -1 to +1 will work just fine!

## 10.0+- This is how far away the end of your part will be from the centerline vertically and horizontally, because we are figuring this out for a right triangle, it’s just half of what it would be if this were a full circle

10.0+- is the angle that the outside edge of your part needs to be off from being perfectly vertical or horizontal (depending on whether you’re looking at the UTM x or y). It’s easy to calculate as 10.0 / tan(angle/2) (where angle is in radians).

The “+-” means that you need to add this to one side and subtract it from the other. The result is that your X or Y coordinate plus or minus this amount becomes valid for the end of your part.

For example, let’s say you have a 10 degree slope, so that tan(5 degrees) = 0.087156, so 10 / 0.087156 = 114.591668. If you’re at an X/Y point of 0,0 and are testing against a part width of 100, then an X coordinate between -14.6 and +85.4 will be inside the part boundary, while anything above +85.4

## 11.0+- This is how far away the end of your part will be from our centerline using both sides of our right triangle.

This is a pretty small number, but we can’t get it any smaller, so you need to make sure that this is what you are after.

Let’s just take a look at where we are and where we want to go with this. Right now we have the angle of the tool to the part, the tool’s diameter and its length. If you took all three of those and put them in the formula for a right triangle, you would get the correct answer for how far away from the centerline your cutter needs to be. The problem is that you don’t know what that angle is yet, so you can’t use it in your formula. That’s why we needed to use both sides of our triangle to solve this problem. We need one side that uses only known variables and another side that uses unknown variables as well as known ones.