# Autodesk Inventor - How to cut Irregular Helical Groove

See tutorial below

1. ### Step 1:

[1]
Create 2D sketch:
- when entering the height: hhh=200 in text box
- select any dimension > right-click > dimension properties > Document Settings tab: Select "show Expression" in Modeling Dimension Display
- this is to be able to see which dimension has got what label (name); e.g. dia = d3 & height is hhh [as shown by the red arrows]

2. ### Step 2:

[2]
Create 3D skecth:
- helical curve
- pitch&height
- "d3" in diameter
- "hhh" in height
- "3.142*d3" in pitch (45deg slope = 1 revolution = 1 pitch)
- rotation direction as required
- (1) pick bottom point of 2d sketch centerline
- (2) pick top point of 2d sketch centerline
- (3)then the end of the base line

3. ### Step 3:

[3]
Create workplane for swept surface:
- new workplane
- pick 3d helix
- pick endpoint

4. ### Step 4:

[4]
New 2d sketch:
- pick workplane
- right-click > "new sketch"
- project geometry > point
- draw horizontal line (line must intersect surface of vase when swept: therefore from centerline out past solid)

[5]
Sweep:
- surface
- profile

6. ### Step 6:

[6]
Revolve Solid:
- revolve
- pick axis

7. ### Step 7:

[7]
3d sketch for swept cut:
- create 3d sketch
- intersection curve
- (1) select helical surface
- (2)(3) select vase (all surfaces)

8. ### Step 8:

[8]
Switch off unneccesary surfaces/workplanes

9. ### Step 9:

[9]
Ceate workplane on end of new 3d sketch:
- new workplane
- helix
- endpoint

10. ### Step 10:

[10]
New sketch to be cut from solid:
- pick workplane
- right-click > new sketch
- project point
- draw circle
-finish sketch

[11]
Swept cut:
- (1) sweep
- (2) cut
- (3) path

12. ### Step 12:

[12]
Circular array:
- (1) Circular
- (2) select sweep feature
- (3) Axis > (4) select vase solid
- (5) 12
-

13. ### Step 13:

[13]
Finished product