Autodesk Inventor

[#1]

Hello,

I am trying to see what kind of a groove I would get if I machine it using a 1 1/4" rotating form tool. We will be cutting these grooves in a CNC milling machine with the tool in the spindle. We have taken a 1" round bar, cut a slot in the end of it and inserted a 3/8" tool bit with a 3/16" radius on it. The tip of the tool will be spinning at a 5/8" radius. (1 1/4" bar).

The bushing will have 2 lengthwise grooves down it at 180°. 2 full rotations each. If I coil an 1 1/4" diameter down the length of the part in inventor, I am not getting a true representation of what the groove will look like, because it is not taking the form of the tool into consideration.

Any help is appreciated.

[#2]

Can you post a picture of the machined item

[#3]

What is the orientation of the tool in the actual manufacturing process (your tool is not perpendicular to the start of the helix path.  You might need to create a helical path, workplane perpendicular to the start and then sketch on the workplane.

Coil always gives an incorrect result unless the start profile really isn't perp to path.  Most don't even realize the geometry isn't correct.

[#4]

I do not have a picture of a finished part. We are creating this into an existing bushing to try and flush contaminates out while the pump is running. These bushings are submerged in water and the shaft that goes through them is rotating counterclockwise.

Mr Mather, the tool will be a high speed tool bit welded perpendicular to the bottom of a 1" shaft. The tool bit will stick out beyond the edge of the 1" shaft 1/8", thus the 5/8" radius. The tool bit will have a 3/32" radius on the cutting edge.

The 1" shaft will be rotating at a high RPM while the spindle moves vertically down through the part (Z axis). As the spindle moves down through the part, the X and Y axis of the machine will interpolate around the center of the bushing.

The part I sent in the original message would only show what a cut would look like if my tool had no thickness. My tool will be 3/16" wide with a 3/32 radius on the end of it. I'm sure it will turn out fine, I was just trying to get a true representation of the groove itself. I'm not sure I understand what you mean when you say to create a plane perpendicular to the coil itself.

We could cut this in our lathe and the I could get a true representation of that cut in Inventor, however, we have decided to cut these in a machining center for other reasons.

[#5]

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tj2057 wrote:

 I'm not sure I understand what you mean when you say to create a plane perpendicular to the coil itself.

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I will post example when I get a chance.

[#6]

Would something like this get you the geometry you are looking for.  This is just one cut to get the 2D profile of the cuttier perpendicular to the cut path.

[#7]

I am having a hard time explaining this.

I have attached another file that hopefully shows how I am trying to machine this part. The red part represents what the tool looks like. The red will be rotating from the spindle and will move vertically down through the part. While it is moving vertically, the x and y axis of the machine will move in sync with each other to cut the tool path on all three axis at once. I was able to make a representation of it in GibbsCam. I found that the thickness of the tool nose (.080) does not make a difference past a certain amount. i.e, if the tool was .030 wide or .060 wide, it makes no difference in the cut. Now, if I were to use a tool 1/4" wide, the path the tool take out would be quite a bit larger. This is because of the relationship between the helix and the fact that the tool is not parallel with the helix path.

[#8]

This is what we mean by perpendicular. I did this coil cut on the outside.

You angled sketch plane would only work if your cutter was angled. Your cutter is perpendicular, so your sketch plane for your cut profile must be perpendicular as well.

[#9 · Accepted solution]

Perhaps this thread might give you some insight:

Sweep Cut a solid

It sounds like a similar problem.  I realize it is not exactly the same thing, but it may prove useful anyway.

[#10]

Thanks cwhetten and everyone else.

attached.

I think I have it solved. I drew a representaion of the tool. I created a workplane at the end of the coil, projected the elipse from the tool and did a sweep cut.

Roll the EOP down.