PUNCH Torino, a European R&D and engineering facility working to develop internal combustion engines and propulsion systems, is using a Markforged composite 3D printing technology to produce camshaft locking tools.
As it builds prototype engines for clients, engineers must install a timing chain to connect the engine’s crankshaft to a pair of camshafts, with valves opening and closing to let fuel and air into them when necessary, as the camshafts rotate.
The camshafts must be kept completely stationary to guarantee the perfect synchronisation of the timing system when the engine is running, and the tools must withstand torque up to 120-newton metres without allowing any degrees of rotation. If the parts don’t match these standards, the valves could allow fuel or air to flow at the wrong time, and potentially damage the engine.
Located in Torino, PUNCH TORINO was founded in 2005, spinning out of GM’s divestiture of the Fiat-GM powertrain joint venture. Under GM’s ownership, it grew from 80 employees to over 700, and in 2020, became part of Belgium’s PUNCH Group. Though no longer part of GM, it has continued to support the company, as well as a growing number of manufacturers and start-ups in diverse technology projects that include gasoline, diesel and hydrogen engines, generator sets, transmissions, additive manufacturing and collaboration software.
THE SOLUTION
To address this, PUNCH Torino has developed fork-like camshaft locking tools (pictured above) using Markforged’s suite of hardware, software, and materials. Previously, PUNCH Torino would have to undertake a lot of trial-and-error work to predict if a tool would have the desired requirements to do the job. Now, it is able to simulate its iterative process, before leveraging the Markforged X7 composite 3D printing system, and fibre-reinforced Onyx mterial, to print camshaft locking tools in print times of 18 hours.
“Simulation has enabled us to eliminate a lot of trial and error in the design of our camshaft locking tools,” commented Valerio Ametrano, Senior Pre-Production Engineer at PUNCH Torino. “It has helped us cut our development time by more than 50 percent.”
Deploying Markforged’s Simulation software technology, PUNCH Torino has been able to reduce the number of printed iterations each time it goes into the development of a camshaft locking tool. Simulation has been designed to allow users of Markforged technology validate part performance and optimise print settings to ensure part requirements are met as efficiently as possible. Users can simulate the strength, stiffness and printability of parts using user-defined settings, while configuring print settings to reduce print time and material consumption.
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Before Simulation, PUNCH Torino would print, on average, up to eight jig designs before landing on the configurations required. Through these eight iterations, PUNCH Torino would be tweaking geometries and dimensions of its camshafts, which would mean a slightly different fork shape would be required to hold it into place, meaning multiple iterations would be printed to understand which shape worked best.
Before simulation
Average number of prototype parts printed per finished tool | 8
Average time to print one part | 18 hours
Total time to print all versions | 144 hours
Development time | 3-4 weeks
Material cost | 1400 EUR
After simulation
Average number of prototype parts printed per finished tool | 1
Average time to print one part | 18 hours
Total time to print all versions | 18 hours
Development time | 1 week
Material cost | 200 EUR
Markforged
IMPACT
Using Simulation, that average number of iterations immediately came down to three, and after the team correctly characterised the boundary conditions, force modulus and deformation the locking tool was exposed to, they now have the data that allows them to print one iteration.
Now, print settings and placement of carbon fibre are optimised in Simulation, with several configurations of manually-placed fibre experimented with to estimate deflection and safety factor. The results of these experiments can be generated in a matter of minutes, while design modifications can be quickly done in the software too.
PUNCH Torino estimates that Simulation is saving the company an average of 18 hours per jig, as well as engineering time that would be normally applied to modifying part designs. Printer time has also been freed up, since there is no longer a need to print so many iterations.
“Simulation frees up our team members’ time to focus on other priorities and the X7 to print parts for other projects,” said Ametrano.
As a company that sells its 3D printing expertise to several industrial ad technology clients, Simulation is expected to be used by PUNCH Torino to help streamline design optimisation and build process for their parts.
