I'm working with a friend to adapt a BMW steering wheel from the 2010s to his Logitech G20 steering wheel base.

A side view of the spline/taper described in the post

A close up of the spline in question

Now, the BMW wheel is constrained in depth with a 90° taper, and in rotation with a 48-tooth spline with two missing teeth.

Sadly, I have no idea what this spline is, or how I'd size a shaft for this to mate with.

The minor diameter of the splines seems (as far as I can tell with only calipers) to be 18mm, and I would not assume that there was anything not metric in this design, because this is BMW.

What is this called, and where can I find tables with dimensions?

  • $\begingroup$ That does not look like a 90 degree taper... $\endgroup$
    – Solar Mike
    Commented Aug 15, 2023 at 15:55
  • $\begingroup$ Make a mold of both and then plan an adapter. $\endgroup$
    – Solar Mike
    Commented Aug 15, 2023 at 15:56
  • $\begingroup$ Well, taking something square (like the end of a machinists ruler, or a normal set square like you'd use for general purpose construction), they seat in the taper perfectly, without any light shining through. To be clear, I was referring to the angle between the two sides, individually it'd be a 45° taper (I'm not exactly sure how to describe them, so maybe I used exactly the wrong way in the original post). $\endgroup$ Commented Aug 15, 2023 at 17:14
  • $\begingroup$ @SolarMike As for casting, this is something I and a friend are doing in our free time, and on a rather tight budget - and while we have access to a machine shop, we don't have any equipment or experience when it comes to casting anything, especially anything that needs details as good as this. $\endgroup$ Commented Aug 15, 2023 at 17:15
  • 3
    $\begingroup$ My first thought is to avoid drawing or machining anything altogether -- find a thoroughly wrecked Beemer with a matching steering column in a wrecking yard. Pull the steering column. Then gut it for the shaft, and use that in your adaptation. $\endgroup$
    – TimWescott
    Commented Aug 15, 2023 at 19:58


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