Rotary Mandrel for an Aircraft Engine Housing Production Machine

Heavy Precision Fabrication for Aerospace Machinery

Aerospace production depends on machines that hold very tight tolerances, and those machines in turn depend on large, accurate steel structures. The rotary mandrel on this page is one of them: a massive rotating assembly, about three metres in diameter and over eight tonnes in weight, built for a machine that produces aircraft engine housings. At Nika Steelworks we made the complete assembly from raw material, including the plates, the rolled and welded conical body, the machined flanges and seats, the hardened circle rails and the large-diameter gear. If you need rotary mandrels, large-diameter machined rings, heavy machine bases or precision assemblies for aerospace machinery, this is the kind of work we are set up for.

Large rotating parts are demanding because every small error is magnified by the diameter. A mandrel that is slightly out of round or out of flat will show up as vibration, wear and poor repeatability in the machine that uses it. That is why accuracy has to be built in from the first operation, not corrected at the end.

From Plate to Finished Assembly

The whole job is planned as one route, which gives you one point of contact and control of quality and delivery. We cut the steel plate by laser and plasma cutting, then form the conical body by bending and rolling. The rolled sections are joined by welding and fabrication in controlled sequences to limit distortion, which matters on a shell this size. After welding, the body goes to machining, where the seats, flanges and fits are finished and the rings of threaded holes are drilled and tapped at their exact positions on several pitch circles.

The hardened circle rails and the large-diameter gear are produced to the same drawing, then bolted to the base with a large number of high-strength socket-head screws. Finally the assembly is checked, painted and mounted on a transport cradle. Because we make the rails, the gear and the base ourselves, they are machined to fit one another, with no need to adapt parts from different suppliers.

Precision on a Very Large Scale

Machining a part three metres wide is a different job from machining small parts. The workpiece has to be supported so that its own weight does not distort it, set up on large-capacity vertical turning equipment, and machined in a sequence that keeps the surfaces in relation to each other. On this mandrel, fits are held to g6 and f9 tolerance grades, and critical surfaces to 0.02 mm for flatness and run-out. We inspect diameters, flatness and run-out against the drawing before the part leaves us, and weld quality is checked as well. You can read more about how we check our work on the quality page.

Handling is part of the job too. Parts of this weight need purpose-built cradles and careful lifting, from İzmir to your plant. We build the cradle to suit the part, so it arrives undamaged and ready to install.

Large Machine Components for Aerospace and Special-Purpose Machine Builders

We work for machine builders who need big, precise steel components made from their own drawings and 3D models. Typical jobs include rolled and welded shells and cones, large flanges and rings, machine bases and welded frames, hardened rails, large-diameter gears, and complete assemblies that bring several of these together. Our standard materials are structural steels such as S235 and S355 and medium-carbon steels such as C45, and we can work in other grades on request.

Typical customers are builders of aerospace production machinery, special-purpose and automation machines, and heavy equipment. We make one-off components and small series, and we are used to the extra documentation and communication that high-value parts need. For a look at the equipment behind this work, see our machine park, or learn more about Nika Steelworks. You can also see more of our work on the projects page, including our steel containers and steel jacking pipes.

Frequently Asked Questions and Quote Requests

Can you build large rotary mandrels to our drawing? Yes. We work from 2D drawings and 3D CAD models, and make the whole assembly from plate to finished parts.

Do you make the gear and the rails as well? Yes. On this project we made the base, the circle rails and the large-diameter gear, and assembled them.

What size can you handle? This assembly is about 3 metres in diameter and over 8 tonnes. Send us your dimensions and weights and we will confirm what is possible.

How is the part inspected? We check dimensions, flatness and run-out against the drawing, and inspect the welds. If you need specific inspection documents, tell us with your request.

Is the work confidential? We treat customer drawings and part data as confidential, and we are happy to sign a non-disclosure agreement before you send them.

To get a quote for a rotary mandrel or another large machined assembly, send us your drawings, material and hardness requirements, tolerances, quantity and delivery location. Contact Nika Steelworks and we will come back with a clear quote.