FIXTURE FOR BONDING DUCTED FAN PARTS – November 5, 2018
The team knew that when it cam time to bond the rear duct parts, we needed a fixture that would keep the duct perfectly round, as this is where the prop spins. Ron Burch, Chief Builder, was tasked with the job. He crafted a round MDF fixture that went thru several iterations, to lighten it up. Above you can see one of the earlier designs. In the photo below, the final design is shown temporarily positioned in the duct.
Once the tube frame was cooled off, we were able to mount it to the rear of the Switchblade cabin section. We validated that the tube frame was the correct shape, and started bolting on the rear body parts.
Above you can see the middle section of the rear body attached temporarily to the rear cabin and frame, with an assembly fixture that looks like an over-sized watch-gear attached to the round opening of the part. This assembly is still being fitted into shape.
This fixture was created to precisely provide the round shape of the inside of the duct where the propeller will be spinning. There is only 1/8″ clearance between the prop tips and the duct, so this shape was created to ensure the duct was perfectly round at that location. The fixture is used while bonding the carbon fiber parts together and then removed once the aircraft adhesive has cured properly.
‘C’ Beams –
While the shape is very important, we also must keep the duct from flexing or moving, so two beams in the shape of a ‘C’ were made to stiffen the duct during flight. In the image below, Chief Builder Ron Burch is matching up the C beams to the ducted fan section where they will be attached.