View Full Version : RFQ: LARGE CNC job - need help

18-10-2014, 01:48 AM
Evening all!

I'm a final year aerospace engineering student, studying at the University of Hertfordshire, Hatfield. I need some help with my final year project, and I wonder if anyone here can help.

For my final year project, I am working as part of a team on a UAV for an international competition: the BMFA Payload 3 Challenge. In essence, the team of four from my University have to design, build, test and compete with a UAV with a 2m wingspan, carrying up to 4kg of dead weight payload. All powered by a single tiddly e-flite10 electric motor.

To me, the answer is obvious: make it out of carbon fibre. Thanks to my placement (http://www.e-goaeroplanes.com/), I can make carbon fibre parts and their moulds. However, we need patterns. I'm going to approach several firms to ask for sponsorship for tooling block (hopefully we'll get some from Trelleborg), but my team needs a CNC shop who can mill the block for us to our CAD models as the Uni's equiment is simply too small. Just to give an idea, each wing will be just shy of a metre long, and will need 2 moulds (and hence 2 patterns) for each. We're going for a radical aerodynamic shape with a blended wing and body design (http://www.wingco.com/atlantica_design.htm), which means we will need comparatively fewer moulds for the entire aircraft.

Before someone suggests sandwich composites (foam wing, CF skin) - that's too heavy for our purpose. Last year's winner had a more powerful engine, and a dry weight of 960grams. We're throwing every weight-saving technique at the job here, and the wing will most likely have several chord length ribs, a single, central spar, and a single CF skin over the top. Strong enough for our purpose, and exceedingly light!

If someone can help us, but can't manage 1m long patterns, it's less critical, as my team can always pin them together, and make a mould that way. The main concern is getting the wing and fuselage shapes out of the 3D CAD package, and into a tangible object we can take moulds or parts from.

What I'm looking for is a firm or individual who can sponsor us with the CNC work. We need 10 patterns (8 if I can design the fins symetrically); or if the quality can be assured, and if each pattern can be made full size in one piece, we could skip the pattern stage and go straight to moulds - something that would save my team a lot of time, money and effort for the same work done by the CNC firm. We have a tiny budget though, and I'm lucky if I'll get back the fuel for the car, as I'll inevitably play taxi for raw blocks and finalised pieces!

What do you stand to gain by this? Hopefully if you've read thus far, you're interested in the project! Unfortunately, due to our budget, I highly doubt we can offer financial reward or payment for your work. However, you'd be working with a University who lead the way in contests such as Formula Student (although admittedly our current BMFA record is less stellar - no composites yet, that's why!), and you would gain advertising and publicity from your markings on our UAV. If someone were to support us, and the partnership was a success, that might encourage the Formula Student team, and others maybe to use you too - not that those necessarily need to be sponsored too!

If anyone can help, please let me know! We're hoping to have the design finalised by mid November, so we'd be looking at around then for the moulds/patterns.

Thanks in advance!