Design Failure of The Mark 3

Test trials of the Mark III landing gears showed that due to its extended length and increased weight acting upon it, it would not be able to withstand the force in the event of a crash. After numerous drop tests, it finally broke when dropped from a height of 40-50cm, carrying a weight of 1.16kg.

Upon inspection it was observed that all the landing gears broke in the exact same spot. Two things could be inferred from this result: one was that the force acting upon each arm was equal during the force of impact, and the second & more important point is that at this particular joint it was the weakest link and where the force acts upon the most. Therefore, the crucial breaking point was analysed and redesigned to cater for a harder impact.

The landing gears were strengthened at the joints and printed on 100% fill, and the drone was drop-tested again. This time it showed to be able to survive a 30cm drop and numerous 60cm drops, which was an improvement over the previous thinner, weaker Mark III landing gears. However, when dropped above waist height, at around 70cm or higher, the landing gears cracked and failed immediately upon impact.

The cracked edges and failure points were taken note of and improved on much better this time, & a new Mark IV landing gear is in progress, with the rib joint being fully extended in length and running across the whole top part of the structure.

The next blog post shall be an update about the new Mark 4 design.

Sincerely,

Ryan

Invictus Mechanical Engineer