I found a great way to make custom aluminum rings and bulkheads for various rocket projects.  Using FrontPanelExpress.com design software "Front Panel Designer" you can easily create aluminum rings and bulkheads.  I have used it to build rings that allow me to adapt between Aeropack and Hypertek motor retainers, for example.  I have also used it to build bulkheads and closure plates for nosecone electronic bays.  I have several examples that can be downloaded and used with the Front Panel Designer software package:

 

  1. 5.38" diameter motor ring with holes for Aeropack motor retainer
  2. 5.38" diameter motor ring with holes for Hypertek 75mm motor retainer
  3. 5.38" diameter motor ring with holes for both Aeropack and Hypertek retainers
  4. 4" diameter bulkhead plate for nose cone electronics bay (built for a scale BBVb, hence the filename)
Here are some example images: