ActOn
ACTON-VIBRATORY-FINISHING
ActOn's Vibratory Finishing Trough machine
Ricoh UK has harnessed ActOn Finishing’s vibratory finishing expertise to enhance the surface quality of laser sintered parts.
ActOn has a comprehensive range of surface finishing systems, but dealing with additively manufactured parts represented new territory for the UK-based firm. However, after working with Ricoh, the company reported a reduced cost per part, consistent results, a projected return of investment within 12 months, and improved the Ra value down to three microns on some components.
Since Ricoh prints polymer parts in a variety of shapes and sizes, the company wanted a vibratory system that could accommodate a load of different parts while achieving smooth surfaces.
“We were aware that the technology was already being used in the industry to smooth 3D printed parts manufactured in Nylon, however, we did not want to simply accept that the established method would be suitable for our polypropylene material,” commented Richard Minifie, Senior AM Engineer, Ricoh UK Products Ltd. “We began to look for a technical partner who would conduct tests across a range of technologies and various media types to provide conclusive data that would allow us to identify the most suitable smoothing process before purchasing the technology.”
Ricoh found ActOn, who ultimately demonstrated how its vibratory finishing technology could smooth surfaces in a variety of times, but not without a few hiccups along the way. Ricoh didn’t have a specific Ra value requirement, but chose the preferred finish and timeframe based on the requirements of its customers. The parts provided by Ricoh included VW bumper components, wing mirrors, and rotary atomiser parts, the initial roughness surfaces of which ranged between 3.6 and 13 microns.
ActOn surface finishing
ActOn initially processed the components in its Centrifugal High Energy (CHE) machine for an hour. The trial was carried using a highly abrasive ceramic media and a concentrated liquid compound, which acts like a cleaner and polisher. ActOn achieved a surface roughness between 1 and 3 microns, but parts were slightly damaged.
Thus, a medium abrasive plastic was used instead of a highly abrasive one. Again, there was damage, so ActOn ruled out the use of CHE. At was at this point, the company turned to its Vibratory Finishing machines. Harnessing the same ceramic media and liquid compound as the first trial, the 3D printed components were processed in ActOn’s Vibratory Bowl machine for 20 hours, and finally achieved parts that showed no damage, and with a Ra value of between 0.5 and 3 microns, looked good. Larger parts were then also tested on ActOn’s Trough Vibratory Finishing machine, which also proved successful. The rotary atomiser head, for example, started at 7.2 microns, and after 4 hours in the Trough machine was reduced to 5.9 microns, and a further four hours, down again to 3.7 microns, with no visible drawbacks.
Damaging on thinner wall sections of parts was noticed during finishing processes between 8 and 20 hours, so Ricoh was advised not to exceed 8 hours and use a mix of sizes of the abrasive ceramic media, the concentrated liquid compound for cleaning and polishing, and water. ActOn also advised Ricoh uses a divider plate to separate larger pars and smaller parts into two different chambers.
Ricoh was thankful for the tips and suitably impressed with the results: “As engineers, we like to capture lots of data to prove processes and learn through experimentation,” Minifie said. “During this collaborative project, we were able to share knowledge with ActOn Finishing to quickly establish a smoothing process for SLS printed parts. This open style learning approach is really important to Ricoh, because the knowledge developed provides value on both sides which in turn increases the chances of future collaborative projects.”
