Q:  Hi, I got the following problem.

I'm trying to draw face-gearwheels.

(see attached image) A face-gearwheel is
created by "rolling" the pinion trough it. I created this one in Acad R14.
This method works, but is very very slow, and I get a real big file in ACAD.
Is there a (easier) way to create a gearwheel like this in 3DSMAX II or ACAD

A:  Here is an idea how you could do it. It took about 10 minutes in MAX 2

You can download the MAX2 file to play with

HERE IS HOW IT WORKS

  • Create a Circle Shape.

  • Create a Rectangle.

  • Select the Circle, go to Create tab, select Loft from the dropdown list. Click on Loft, make sure the Instance option is selected, and get the Rectangle for Shape.

  • Add an EditSpline modifier to the original Rectangle

  • Insert vertices and make it look like the cross-section of the wheel at the highest point of the teeth.
    The Loft object will react and display a HIGH zone where the teeth are going to be...

  • Create a Copy of the Rectangle, go to Sub-object level and move the vertices at the TOP of the tooth down to set the LOW part of the tooth.

  • In Modify Tab, go to "Path Parameters".

  • Check the "Snap On" checkbox and enter a snap value of 2 (or any other value - this defines the number of teeth)

  • The value of 2 means tha low/high cross-sections will apear every 4 (2+2) percent of the path's lenght. This gives 25 teeth. (4*25 = 100%)

  • Now, with value 0% in the Path spinner, press the upper arrow of the spinner - you will get the value 2..

  • Press the Get Shape button and select the Low Tooth shape (Rectangle Copy).

  • Click the upper arrow of the Path spinner again - it increases by 2.

  • Get the High Tooth again.

    •  
  • Press the arrow up, get the Low Tooth etc.... (Repeat until Path=98%)

    It requires some clicking around, but it is faster than you think.... :o)

    Also, you can change the detail by setting the Shape and Path steps in the Loft to different values. The model on the picture has 10400 faces / 5200 verts. (Shape Steps 1, Path Steps 4)

    Here is what it looks like after rendeing:

    Face-gearwheel Lofting Tutorial
    (c) 1998 by Borislav "3DJ Bobo" Petrov