Foam is good because it’s light but t’s not as strong. It also resonates more, meaning we need more of it to have the same vibration reduction. Effectively this means the same weight in material of either material produced the same result. The benefit of going back to carbon is that I can customise layering to increase the strength and vibration resistance even further, which is not something that can be done with foam.
We’ve beefed them up a bit, but also made them smaller (because the arms are now smaller at the ends). We wanted to cut the break rate down and this means an extra gram or two across the frame. However, the arm changes counteract this increase in weight. For the increase in weight, we’re seeing a marked improvement in flight characteristics. BOOM!
We’re really confident about the overall strength and durability of the motor mounts which are a cause of doubt for many people.
In other news, we tested carbon mount arms. While a fun test, we were not surprised at the results in the slightest. Hard carbon mounts fail to deal with vibration problems and freak the FC out. A hard mount arm without an accompanying brace is asking for problems it seems and the additional weight of a brace would have undone any benefit a hard mount would have added. This reaffirms our belief that alternative material arm ends are the way forward for our vertical frames. 🙂
Ultimately the design and functionality are 99% the same, we just made these changes to improve durability and performance.