CNC Machining and Hand Crafting
Here at Hercules we are huge advocates of using high technology to produce the most consistent, reliable and efficient results in our production processes. To that end we use an in-house designed and built Computer Numerically Controlled (CNC) machine to sculpt our propellers from their laminated wood blanks, before handing them over for some final hand-crafted finishing work.The CNC machine uses the 3D computer models created as part of our design process to run several stages:
- Cutting the slot for our Hercuthane leading edges
- Drilling the centre bore, bolt holes and drive bushes
- Initial roughing cut – the mesmerising part of the process where the propeller miraculously appears out of the wood)
- Finishing cut – taking the propeller down to its final shape
Every Hercules aircraft propeller starts its life as rough sawn Grade A timber. From initial delivery our wood is carefully sorted and stored ready for selection, before being prepared in-house.
- The wood boards are chosen individually for each propeller, initially by size. They’re then cut to very exact lengths, widths and thicknesses depending on the requirement – the majority of our propellers are made up of laminates of 4, 5 or sometimes even 6 layers.
- Once the boards are cut to size, they’re sorted according to grain direction and stacked in order.
- Glue is spread evenly on both sides of each bonded join between boards using a specially calibrated spreader, before the glued faces are then put together. Each board is glued in the same way until the full laminate has been constructed.
- Once the boards are all glued, the laminate block is then secured under very high pressure in our custom built heated glue press. The blank is then left for the glue to bond for several hours.
Precision Balancing and Finishing
Each and every propeller that passes through the Hercules factory is precision balanced throughout the manufacturing or refurbishment process, with a final tuning happening at the end.
Our propellers are tracked and balanced on a 360 degree rotational balancer, meaning the propeller is balanced for every point throughout its full circle of rotation, making it exceptionally smooth running.