If you're trying to add spokes to your pie chart then, since v2.8.0 of shinobicharts, there's a much easier way than that described in the blog post. Spokes are now supported out-of-the-box and are enabled by setting
style.spokeStyle.showSpokes = YES on the pie/donut series’ style object.
There's a more detailed explanation of how to use spokes in the shinobicharts userguide.
I hope that helps.