Frequently Asked Questions
Rotolatch™ Technology and Specifications
Design Flexibility Note
Dozens of parameters of the Rotolatch™ system can be tuned for specific applications. Generally, increasing the size of the hook and latch can increase load bearing capacity and reliability, while shrinking the system will, of course, reduce cost. Material and manufacturing method selection will also influence performance and cost. Below, we will answer questions based on our current prototype geometry which is tuned for 3D printing in PETG. Just keep in mind, we’ve made very small, functional Rotolatch™ systems and we could make beefy, metal systems to lift large loads as well.
Yes! In fact, our 2 pin designs use less material and have other benefits that make them a preferable choice for most applications. Our demonstrations show the 3 pinned system because the specific designs for a reliable 2 pinned system are currently still trade secret. Please contact us to discuss.
Our current system has been tested to engage 1000 consecutive times without failure with an axial offset of 1cm. We believe this is plenty of flexibility for most automated systems, but the geometry can be tuned to increase reliability at larger axial offsets for specific applications.
The Rotolatch™ system was originally designed to be easily injection molded. Our cost-optimized latch design is a two-piece assembly. We have not invested in molds because our 3D printed PETG parts work just fine. Rest assured, our injection-molded part design was created by an experienced plastics designer and licensed professional engineer. We expect an injection molded system to be smaller (due to reduced friction) and more reliable than our 3D printed parts.
The hooks can be injection molded for between $0.02 and $0.08 depending on material and load requirements. We have hook designs for minimal material use material to reduce cost and environmental impact. The boxes may require an additional cut-out and assembly step, which will also increase the cost of implementation on a package. Also, box stacking requires spacing for the hooks.
Yes. Disengagement requires a differential, vertical force between the hook and the latch. On a drone carrying a package, this means the package would need to experience a significant upwards force that does not also push the drone upwards, or the drone would have to move downwards at an acceleration greater than gravity. While we expect these events are extremely unlikely, we understand that drone delivery applications will require extremely high reliability of package retainment, so we have design options that can be implemented to further increase this reliability if necessary.
Drone Delivery Methods
Here is the full view of a run by a UT-Dallas UTDesign team of both the pickup and drop-off processes without any camera jumps
While the Rotolatch™ system can accommodate for substantial misalignment, precision landing with manually controlled, hobby level drones is quite difficult. The cones on the pickup station align the drone to the package upon landing. Slightly more advanced drones can reverse this and put small funnels on the drones with alignment poles protruding for the pickup station. Even more advanced drones may not need alignment assistance at all.
The Rotolatch™ was originally designed to be used on a tether or cable. We chose to focus on demonstrating the system on a fixed bearing because we believed it to be both a greater challenge and a more valuable solution. We have a system design for reliably aligning a tethered latch to the hook.
Of course, the physical bearing and latch system must be fixed to the drone. The actual attachment will depend on the specific application and other drone design goals, but the system is quite flexible. Our current system includes a switch array that detects engagement and payload presence, so it only needs two logic pins and two power pins. Our detection system is extremely low cost, compact, and draws insignificant power.
Business Opportunities and Value Proposition
Several companies have developed methods for automated drone delivery, but the Rotolatch™ allows a simple, cost-effective, reliable solution for pickup as well as delivery. This means a drone can complete a fully automated delivery loop by picking up a package, dropping it off, and then picking up another package, all without human interaction. Conceivably, a truck could drive through or park in a neighborhood while feeding drones packages for delivery. The drones could then dock and charge as the truck drives to the next neighborhood.
Remember, the only actuators required for the Rotolatch™ system to work are the propellers on the drone. Not only does this decrease weight and power consumption, but it is less complex, more robust, and faster than an active latching system.
Since different applications will require slightly different designs, we do not currently have plans for manufacturing and selling this as a product. Instead, we will offer licensing and design support for your application. Please contact us for details.
We have considered dozens on dozens of applications for this technology, but we think the emerging drone delivery market will see the most value from it right now. If you are interested in implementing the Rotolatch™ in a different market, please let us know.
We are eager to help. Please contact us.