First post here, trying to get a little help with Autodesk Inventor.

I am trying to make a part that is basically a wheel with little nubs on the end (think of a lego with tabs on the outer circumference).

What I tried so far is making a rod and using the Constraint function to make the parts one piece. Is there a more direct way to do this? I can't seem to find a way to just add the tabs/nubs on the edge of the circle.

enter image description here

  • $\begingroup$ Pro tip: if you ask a question, "help with X" is a very bad title. Instead, give a title which says, what is the help what you want. People wanting to answer questions see 50 question titles in a column, your goal is to help them to find yours. $\endgroup$
    – peterh
    Commented Oct 13, 2018 at 1:19
  • $\begingroup$ What you did is a "direct way". Remember the exact shape of the patch on the wheel rim at the base of the nub is quite a complicated three--dimensional shape. There isn't likely to be a "quick way" to find that shape, except by intersecting the shapes of the wheel and the rod. $\endgroup$
    – alephzero
    Commented Oct 13, 2018 at 13:10
  • $\begingroup$ AutoCAD and Inventor (both made by AutoDesk) are not the same software $\endgroup$ Commented Oct 14, 2018 at 17:32

1 Answer 1


The way I would model the component shown on the LHS of your image is like this:

enter image description here

  1. Sketch the outer diameter of the circle on one of the home planes, say XZ, with the centre of the circle at the origin.
  2. Extrude the circle an equal distance in each direction, such that the XZ plane runs through it's centre
  3. Sketch half of a 'nub' on the same plane, with a centreline along the X axis
  4. Revolve the 'master nub' by 360degrees around the centreline in the sketch (coincident with the X axis)
  5. Use the circular pattern tool to make 4 copies of this nub, equally spaced, around the Y Axis.

The reason I suggest this approach is that it ensure that the nubs are all identical to one another, and all equally spaced and pointing radially out from the centre of the circle. IF you want to edit the form of the nubs, there's a single sketch to edit, and all other nubs will auto-update.

Using relations to control the position of things is dangerous, as they rely on the internal ID's of selected faces etc, and these are notorious for getting 'lost' as a result of model changes elsewhere in your workflow.

  • $\begingroup$ Perfect! This was exactly what I was looking for. Originally I used a frame of sorts to get all the rods equally spaced, but I just eyeballed the circle placement, so it wasn't 100%. Your approach eliminates the need to make separate parts and assemble them. This also helps when converting to an STL. When I converted to an STL it was just converting a few rods and not the full part. That all said, thank you very much! $\endgroup$
    – TheUnicorn
    Commented Oct 16, 2018 at 3:41
  • $\begingroup$ No problem - glad I could help. You would need to use the 'Combine' tool to merge the different solids into one object before exporting the STL with your previous approach: i.imgur.com/NBhiMJP.png $\endgroup$ Commented Oct 16, 2018 at 3:58

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