Protec has built up a strong client base in the motorsport industry for its brushless DC fuel pumps. Its products are currently found in the likes of Le Mans Prototypes, IndyCars and next-gen NASCAR. Owner Rob Schirle tells us that 3D printing allowed his UK-based company to not only design more effective products and manufacture them more efficiently but also to permit its overseas distributors to produce certain components themselves at their own facilities.
Fused filament fabrication (FFF) is a 3D-printing process whereby a continuous filament of a thermoplastic material is fed from a spool through a moving, heated printer extruder head. The computer controlled head deposits the material in horizontal layers so as to build up the required item. While FFF machines can be inexpensive, and as such have built up a strong hobbyist sector, more professional versions can nowadays provide a more affordable alternative to the likes of high-end SLA (stereolithography) and powder bed fusion.
In the case of Protec, FFF allows its distributors to produce in-house certain components with all the functionality – or more – of an aluminium alternative, having made a modest investment in the required machine, which they can also put to other uses. Protec is working with Barcelona, Spain-based FFF machine manufacturer BCN3D and Milan, Italy-based filament supplier Filoalfa.
While an affordable BCN3D machine can produce, for example, a collector suitable to replace an existing aluminium item, a key consideration is the resistance of the material used to the type of fuel it will come into contact with. This is where Protec’s relationship with Filoalfa is paying dividends, Schirle explains.
Working with Filoalfa, Protec has developed several filaments suitable for use inside the fuel cell, including a filament dubbed Thermic Z that is resistant to all chemicals that can be present in a given racing fuel. This is worked using a bed temperature of around 100 C – similar to that of more conventional filaments – but it requires a nozzle temperature not of the 250-280 C at which, for example, a more conventional aliphatic polyamide (nylon) would be worked but of 300-350 C. Protec has cooperated with BCN3D to obtain a suitable nozzle temperature, which is beyond the normal operating parameter of the Spanish machines.
One advantage of Thermic Z is its resistance to all known solvents up to 200 C, and that it is not hydroscopic, unlike most conventional filament materials. This eases storage of the filament spool and pays dividends when the fuel in question has a high ethanol content. Compared to a regular filament its cost is double, but Schirle notes that when the costs in question are 13 pence per gram versus 18 pence, and the total requirement is typically 120 g, the additional material cost is negligible.
From the perspective of a distributor who has invested in a BCN3D machine, all that is required to produce a given component is the particular Filoalfa filament supplied by Protec (to suit the given application), a digital file sent over the internet by Protec and a supply of electricity. The cost of manufacturing that component is then a fraction of what it would have been had it been machined from aluminium – and in any case the distributor would almost certainly have imported the item from Protec instead.
With the process of FFF manufacturing from a supplied file not requiring specialist expertise, Protec’s new model thus saves on transportation costs and logistics, overcoming potential supply delays. As is well-known, additive manufacturing saves waste compared to subtractive while also allowing for geometric forms that even five-axis CNC machining wouldn’t cope with.
Schirle adds that advances in filaments “have been vast over the past 3 to 4 years, enabling for example the use of Peek and Ultem”. He acknowledges that the finish obtainable from FFF “is not quite as good as SLA [stereolithography 3D printing] or a powder type [additive manufacturing], but for the amount of detail we need, we don’t need it that fine.”
Schirle notes that these days some BMW tuners are extracting over 1000 bhp while retaining a stock fuel tank. The Protec brushless DC pump is very small yet can supply sufficient fuel for up to 900 bhp, beyond which a second one is required.
Protec has devised a clever method whereby the stock ECU can interface with its own controller so as to be able to control both pumps. It has also managed to keep its dual pump system within the car’s regular amperage.
However, this system requires a complex collector design. FFF allows that to be created in such a way that beneficially retains the standard tank flange, which would not be feasible using traditional manufacturing techniques.
Schirle adds that using FFF, Protec has been able to rethink its entire approach to the design of components. It seems only yesterday that Formula One teams were singing the praises of newly developed SLA and then powder bed fusion, which were unaffordable for much of the rest of the racing industry.
They still are, but it is clear that the gulf between top-end additive manufacturing and unsophisticated hobby-level FFF is being bridged by technology that the average race team can put to many practical uses. The Protec approach indicates how FFF capability stands to become as commonplace across the racing landscape as CNC machining is now.