Precision is what counts in aircraft assembly.
It is essential that various individual parts are precisely screwed or riveted together in the assembly of aircraft. Drill jigs are used to ensure that each drill hole is set precisely at the connection points. Any error, no matter how insigificant in itself, can have highly risky and extremely costly consequences. Since these drill jigs hardly wear out, they are in use for decades. This means, that it is not uncommon that they no longer comply with current, stricter ergonomic regulations.
For this reason, Ascent Aerospace wanted to optimize a heavy and unwieldy drill jig. The template consisted of several solid aluminum plates that were conventionally milled and joined. The jig was used to precisely drill holes for the guide rails of landing flaps on the wing spars.
Ascent Aerospace's aim was to make this drill jig significantly lighter and more ergonomic so that the physical strain on the fitters when lifting and attaching the drilling aid would be reduced. At the same time, the template is easier to handle. Other requirements were that the new assembly aid had to be able to be integrated seamlessly into the existing manufacturing process and be available quickly.
As a specialist for additive manufacturing, FIT had the right expertise for additive design and engineering, prividing the perfect solution using ist Rapid tooling solution.
Precision begins with the design
A feasibility check at project start showed that the outer geometry of the drill jig could be optimized, but that alone was not enough to save significant weight. For this reason, we completely revised the design of the template as part of an ADM-E project.
The newly designed drilling aid was constructed in one piece and hollow. The stability required by Ascent Aerospace was achieved by curved sections, angled connecting surfaces, and perfectly vertical hole fits that act as bracing to connect the hollow walls. In addition, the designers at FIT paid meticulous attention to ensuring that the new design could be additively manufactured with as little material as possible and largely without support in a cost-optimized manner.
As an additional element, slots for small mirrors, so-called target holders, were integrated at the corners of the newly designed drill jig, through which the exact fit of the drilling template is verified by means of laser optics.
Controlled precision during production
The drill jig was manufactured at FIT from aluminum (AlSi10Mg) using laser melting (LM or PBF-LB/M). The new design made optimal use of the 3D printer's installation space, allowing it to be built in one piece despite its size. The drilling template was then blasted and selectively CNC milled on the functional surfaces.
Extensive quality assurance measures were carried out to monitor the quality of the assembly aid before, during and after production. Material quality was ensured by means of a powder analysis. The building process was monitored layer by layer by an optical system. Thanks to tensile tests and density cubes, the stability of the building process and thus the component quality could be verified. The drilling template was visually inspected after production. The geometry of the assembly aid was verified by an optical 3D scan. Finally, the mechanically machined elements of the template (fits, contact surfaces, etc.) had to undergo tactile 3D coordinate measurement.
The result: The drilling template exactly met the specifications and could be tested by Ascent Aerospace 30 days after project start.
The special process requirements
The particular challenge in this project was to optimize an existing tool in such a way that it fulfilled its function and the associated technical requirements at least as well as the conventionally manufactured drilling template used to date. In addition, however, it had to be significantly more ergonomic and within budget. FIT succeeded in this by radically optimizing the design. This made it possible:
The project was successfully carried out by FIT and has initiated a generation change for the design and manufacture of assembly aids at Ascent Aerospace. The next step is to see if a material change to plastic is possible to further reduce manufacturing costs.
Do you have similar challenges in your company and would like to optimize your assembly aids and jigs? Great. We look forward to getting in touch with you.
|FIT solution:||Rapid tooling (assembly aids and jigs)|
|Scope of services:||Design development and simulation
Additive manufacturing and post-processing
QA documentation (material test certificates, material certificates, measurement reports)
Packaging and shipping
|Delivery time:||30 working days|
|Part dimensions:||503 x 347 x 153.5 mm|
|Part weight:||4.67 kg|
|Material:||Aluminum alloy (AlSi10Mg)|
|Technology:||Laser melting (PBF-LB/M)|
Selective milling of boreholes and fits
|Quality control:||Visual check
3D scan of geometry
Complete tactile measurement of the machined component elements (fits, contact surfaces, etc.)