In the many months since we took over Superior Props, we have dedicated much time to reviewing the manufacturing processes, quality control, and accuracy.
For example, we have developed an accurate pitch gauge to check the output product. This caused us to rework all of the pitch templates to ensure the same pitch across the entire blade – both blades (true helical pitch). We have cleaned up the hub section and tapered the thickness of the blades.
Also, We have done research on many, many Old Time propellers. The Cloud Tramp props shown here have all been made to match Charles Hampson Grant’s specifications in his book “Gateway to Aero-Science”. This includes length, width, thickness, and pitch. We are gathering all the OT Prop Data we can to provide propellers just the way the designers wanted. We have many specs, but we would love to have prop specs provided from customers.
We are reporting the calculated density of each blank. This is done after the raw block is cut and before it is machined. The volume is measured and the block is weighed and the density is calculated. While we cannot offer much in the way of the customer density selection, we do allow thicker blades on the lighter densities so the customer has wood remaining for strength.
The values shown here are from our latest batch of wood. We had a supply of wood but it ran out when as we produced propellers. Strangely, it had a wide range of densities – 7-16 lbs/cu ft. This box, has some very fine wood; it seems to be 5-8 pound wood.
This is all in an effort to offer the best propellers we can. And we will continue to improve wherever we can.
