2005 University Challenge Heavy Lift Model
Team Members: Matthew Hoyland & Tim Turner
The essence of this project is the design and build of a Radio Controlled small aircraft to carry a predicted payload.
The BMFA in partnership with BAE Systems annually organises the university heavy lift challenge. The contest itself is based upon the requirement to design and build a radio controlled model aeroplane to carry a predicted payload. A contest specification defines various parameters such as engine size, cargo bay dimensions, the take-off runway length and the flying pattern to be achieved once the model is airborne; this ensures participating teams conform to the same requirements.
The result of the design process is a model that will have a 3m wingspan and use a 'Kenmar' airfoil section shown below. The model will be powered by a standard Irvine 40 on 5% nitro. It is expected the model when fully loaded will weigh in the region of 12kg.
The Kenmar airfoil section.
The ribs for the wing were cut using a £17000 laser cutter. Before this took place the wing was fully modelled in the 3D CAD system Pro Engineer and exported to Corel Draw before being put into the laser cutting software.
The balsa below the airfoil section was used for the jigging of the wing to ensure each rib was in exactly the right position. This will be removed once the wing has been sheeted on the top surface.
The standard Irvine 40 shown against the root rib of the wing. At this stage the wing was simply slotted together with no glue. The burn marks from the laser can be clearly seen of the spars.
Shear Webs have now been added in between the spars as can be seen below.
Engine Static Thrust tests on the Irvine 40.
An APC 12.25 x 3.75 produced the highest static thrust of 30.41N turning at 11200RPM.
The tail-plane ribs and spars were also laser cut.
The fin and rudder were also laser cut. Too much power lead to the balsa burning on the fin. The burn marks can be clearly seen and where a fire really took hold an additional piece has been spliced in. Two JR DS3401 servo's will be used on elevator and a JR DS8401 will be used on rudder. The space for the elevator servo can be seen in the photo below.
The addition to the second rib will fix into the tubular fuselage.
At this stage the wing weighs 482g. Top sheeting still to finish on one half and the whole of the bottom is still to be sheeted.
The front and rear wing bolt plates can be seen below.
The wing is now finished, weighs just over 2lb (0.9kg)
It is hoped test flying will commence on the 22nd May 2005.
The competition will take place on 5th June 2005 at Elvington.