
AM Craft
Bottom view of arm caps showing (left to right) the part being replaced, the unpainted 3D printed equivalent, and two colours of the final printed part.
LOT Polish Airlines is installing 3D printed arm caps, designed and manufactured by AM Craft, on their fleet of Boeing 737 planes.
The airliner is the flag carrier of Poland and operates more than 80 aircraft, serving destinations across Europe, Asia, and North America.
LOT as turned to 3D printing as sourcing replacement parts becomes increasingly difficult, with parts unavailable from the original manufacturer having extended lead times and often requiring design enhancements.
Because of this, LOT linked up with AM Craft for the design and additive manufacture of arm caps for the economy class seats on their 737 fleet. Originally, the conventional arm cap was produced in multiple steps with a rubber cap surface attached to an injection moulded frame which was attached to the seat. The interface between the rubber cap and plastic frame was prone to degradation, however, meaning the cap would not stay in position on the frame and occasionally coming off in the passenger's hand. The plastic frame would also frequently break where it attaches to the seat.
Using Stratasys FDM technology and the ULTEM 9085 filament, AM Craft designed a new arm cap as a single piece, eliminating the interface issues between the two parts, and redesigned the interface to the seat in order to reduce the risk of breaking in the location that the previous design had experienced. With Mankiewicz’s ALEXIT coating system, AM Craft also managed to colour match the LOT Polish cabin interior.
Through this application of AM, AM Craft was said to offer LOT a more cost effective low-to-mid volume price than the conventional component. In total, 1,200 arm caps were produced by AM Craft for installation on Boeing 737s in the LOT Polish Airlines Fleet. AM Craft managed the certification of the arm caps and is delivering them to LOT Polish Airlines with an EASA Form 1 Airworthiness Certificate.
“Originally, we intended to just replace the broken arm caps with replacements from the seat manufacturer, but the AM Craft part was such an improvement that we replaced all the arm caps with the 3D printed version,” said Maja Margul, Continuing Airworthiness Junior Specialist at LOT Polish Airlines.
“LOT Polish Airlines has a long history of leadership in commercial aviation,” added Didzis Dejus, CEO of AM Craft. “We are proud that we were able to leverage our expertise in design and certification of 3D printed aircraft components to solve their supply chain problem with these arm caps, and we look forward to helping them address additional challenges. For commercial aviation, 3D printing has clearly become a highly impactful technology while no one was looking.”
Last year, AM Craft announced a partnership with Stratasys aimed at advancing the application of 3D printing in aviation. It came after the company deployed Stratasys AM technology to deliver 300 cabin replacement components to Finnair.