- By: Ken Gracey Published: 10 December, 2015 0 comments
Gracey: You’ve been actively working in seclusion for 6 months, and we haven’t really introduced you to our customers. Can you tell us a little bit about yourself first?
Montgomery: Sure! I graduated from Bucknell University in May, with a BS in Mechanical Engineering. I joined Parallax in June and immediately began work on the ELEV-8 v3 Quadcopter, and then a month later joined the Flight Controller development team. While I first got involved in robotics in 2003, I only began working with UAVs in the fall of 2013, when some classmates and I built a quadcopter that went on to win an entrepreneurial engineering design competition. I interned with Parallax in the summer of 2014, working on updating the design and documentation of the ELEV-8 v2. In my free time, I can often be found on the trails of the Sierra Nevadas hiking, running, or working with the local Search and Rescue team. I’m also a bit of a photography buff.
Gracey: Tell us where you jumped in with the design process?
Montgomery: When I joined Parallax in June, the Flight Controller had already been in development for a number of months. The team already knew that they wanted to integrate it into the ELEV-8 Quadcopter Kit as soon as it was ready, so they asked me to look at how it would be integrated and if any changes to the airframe might be necessary. We determined that while it would work with the ELEV-8 v2 without any other major modifications, we felt that the new Flight Controller was such a significant leap forward that choosing not to upgrade the rest of the quadcopter would be leaving far too many cards on the table.
Once we committed to developing the ELEV-8 v3, I created a survey for current and prospective ELEV-8 users. The responses we received were instrumental in shaping our design objectives for the ELEV-8 v3. Customers listed durability and reliability as the two most important attributes for a UAV, so those became one of the primary design objectives. So I chose new (and far more reliable) ESCs and designed a significantly more durable chassis. In the end, only one part of the entire ELEV-8 v3 kit was continued over from the v2 - the landing gear!
Gracey: There’s so much to talk about in regards to the ELEV-8 v3. For the sake of brevity, let’s just start with the airframe — what changes did the design goals lead to?
Montgomery: In addition to added durability and strength, our design goals also included improving the assembly experience and making modification and repair even easier. The central chassis plates are now machined out of a composite—they are so strong we’ve never broken one! I redesigned the motor mounts to be lighter and more rigid to reduce vibrations, and they are now a sacrificial part in a crash, breaking away to reduce the likelihood of damaging a motor. The flight controller isolation system took a lot of testing to develop, but the final design is able to reduce vibrations by about 70%. Even though it’s much stronger, the ELEV-8 v3 is 5 ounces lighter than it’s predecessor! It’s also capable of carrying 3 lb payloads or flying 20 minutes on a single battery. For portability and storage, the whole chassis is also folds down to 1/5th the volume by removing eight screws.
Gracey: You have significant experience in computer-aided design (CAD) from your engineering program at Bucknell University. How did that experience affect the v3 design process?
Montgomery: After we’d finalize the goals and engineering specifications for the v3, I began work on the design morphology, which evolved from hand drawings to CAD. I’m able to use our CAD software (SolidWorks) not only for producing manufacturing drawings, but also for structural analysis and mass calculations. For the ELEV-8 v3, it was very important that the center of mass stay exactly at the geometric center for optimum performance. Being able to monitor that was very useful when designing the Tarot Gimbal mounting plate (coming soon!) since it has to be balanced by the battery. The final CAD model of the ELEV-8 v3 includes every single component except for wiring. Since this product is open-source (, all of the design files will be released (when the product begins shipping) in native format for the public's use!
Gracey: Have you crashed a number of these during the design process?
Montgomery: Yeah, we’ve crashed quite a few times, especially early in the project. When developing (and testing) new flight control hardware and software, crashes are inevitable. While the final product is easy to fly thanks to it’s auto-leveling capabilities, getting to that point was a long and bumpy road. I’ve been know to say “we wouldn’t have learned as much if it didn’t crash” - every crash is a learning opportunity to fix a bug and improve the product. Crashes have also been a great test of the new chassis—most of the minor crashes resulted in no damage, and the most serious crash, where it plummeted into the ground at about 23 mph, only damaged a boom, motor mount, and two propellers. As for ease of repair, the quad was back flying again after only about 30 minutes! Since since customers can buy spare parts from Parallax in Rocklin, CA, or make their own, they’ll never be grounded for long. As designed, the sacrificial Motor Mount broke in the crash, protecting the motor from damage Aftermath of crashing in the snow - the snow was quickly removed and the ELEV-8 was undamaged
Gracey: When will the ELEV-8 v3 start shipping?
Montgomery: Everything is in production now, and we expect to start shipping on December 18th.