Gloucestershire, UK-based Retro Track and Air has invested in a Haas CNC VF-5/40XT – a 40-taper vertical machining centre with an extra-long, 60 inch (1524 mm) table – to machine cylinder heads for the famous V12 Merlin aero engine.
Installed in Retro’s newly built facility beside the company founder’s family home, the VF-5/40XT is a snug fit, towering over an adjacent Haas CNC Toolroom Lathe, and working long hours under the supervision of Gavin Faulks, head of design.
As the company’s name suggests, Retro Track and Air specialises in rebuilding and maintaining winged and wheeled masterpieces from a bygone era. Housed in various outbuildings – as well as a hangar at a nearby airfield – are various single-seat racing cars undergoing rebuild and maintenance before the new season. There are also partly restored aircraft and aero engines, some of which are the property of the Royal Air Force Battle of Britain Memorial Flight.
Gavin Faulks: “The Haas VF-5XT is perfect for machining the Merlin cylinder heads, designed more than 80 years ago by Rolls Royce. With all the parts we make for old engines, we work from drawings that are at least as old, which means we often have to reverse engineer components or best-guess dimensions, etc.
“The castings are made to a material specification called RR50 – created by Rolls Royce. It’s exactly the same material and part design as it was when the Merlin engine was first run, in the early 1930s. It would be relatively straightforward to modernize aspects of the engine design – to remedy small design faults – but the demand is for authentic parts, without any changes from the original.
“This particular batch of cylinder heads – seven off – will take us two years to finish and deliver to the Royal Air Force. Tolerances – between the arrays of bolt holes, for example – are 0.025 mm. Each face takes around a week to machine; the inlet/exhaust faces take another half a week. All the programming is done offline on OneCNC.”
“The new Haas has enabled us to keep more of this type of work in-house, and not rely so heavily on subcontractors. As a company, that’s the general direction we are heading in. To do so means making an investment, of course, but the difference between the parts we used to get – or make in-house on old machines – is night-and-day. The repeatability of the Haas is excellent, and it’s very reliable and easy to use.
“Although we can’t change the design of the parts, we are machining them to a higher standard, which, in itself, is a big improvement.”
The new Haas has enabled us to keep more of this type of work in-house, and not rely so heavily on subcontractors. As a company, that’s the general direction we are heading in. To do so means making an investment, of course, but the difference between the parts we used to get – or make in-house on old machines – is night-and-day. The repeatability of the Haas is excellent, and it’s very reliable and easy to use.
Gavin Faulks
For Example: When a rotary fits with alternative fixturing, it may fit in that particular Haas mill, but will require a sub-plate or alternate T-slot for proper positioning. We have labeled this particular rotary and mill combination with a yellow caution
You can design and build your own sub-plate using the dimensions of your Haas mill and the dimensions of the rotary you'd like to use on that mill. Product dimensions are available for every machine and rotary on this website.
Single-Head Rotary Tables and Indexers are usually mounted to the right side of the table, with the rotary facing the centre of the machine. This is the basic setup we used to determine the fit of your rotary product.
Image shown for mounting example purposes only. Your actual rotary and mill appearance may differ.
Trunnion Tables, T5Cs, and TRTs are usually mounted in the centre (or slightly off-centre) of the mill table. If you are using probing on the mill, be aware of the interference with larger tools, especially during tool changes.
NOTE: Trunnion units present interference issues with the swing of the unit relative to the machine column and spindle head.
Image shown for mounting example purposes only. Your actual rotary and mill appearance may differ.
Multi-Head Rotary Tables and Indexers are usually mounted toward the back of the table, with the indexer heads or platter facing forward. To mount a multi-head rotary in a different orientation, you must use alternative fixturing.
Image shown for mounting example purposes only. Your actual rotary and mill appearance may differ.
Important Information:
4-axis machines cannot use dual-axis rotaries.
Some options may affect mounting (EC-1600 4th-Axis Table, Low-Profile Tables, Table Spacers, Column Risers, etc.
Tool Changers: SMTCs and umbrella tool changers both present interference issues, plan appropriately.