The "Hornet" 450 (WORK IN PROGRESS)
I started flying R/C Helicopters in late 2011/early 2012 and after I felt comfortable flying my Blade CX2 I decided to take the plunge and buy an Align Trex 450 clone, specifically I bought the HK-450GT from Hobby King for $50. The HK-450GT is actually a "99%" clone of the Trex 450 SE V2 design and my philosophy was, "I'm going to crash this thing learning to fly, so I might as well make it cheaper on myself." One of the things I soon learned to hate about the design of the 450 V2 chassis was the "stacked" frame plates. Anyone who owns one of these should know what I'm referring to, but for those who don't please see the below picture.
You should notice that the frame is comprised of a stack of "frame plates," an outer and an inner set, separated by spacers. Now this design has worked for years and the Trex 450 SE V2 is one of the most copied and cloned R/C Helicopter designs on the market. But the way I saw it from a maintenance service and manufacture standpoint, it was far from ideal.
So in the Fall of 2012, I took an engineering course as part of my degree that focused on "Concurrent Product Process Design." Basically, the course looked at how to design parts and assemblies for manufacture and service life maintenance. As part of the curriculum, we were assigned the task of taking a real world product or problem and designing an alternative to address the philosophies of Design For Manufacture (DFM). I suggested to my design group that we tackle redesigning the frame of my HK-450 and the project began.
The first step is to determine your design intent, or what you hope to accomplish in your design. For our re-design, it was decided to focus on part reduction and fastener standardization. We wanted to eliminate two of the frame plates and in doing so eliminate the need for the frame plate spacers present in the original design. This would have a third benefit of allowing us to standardize on one length of fastener to hold the new frame assembly together. We also wanted minimize how many new parts we would be required to design in order to maintain access to the wealth of aftermarket parts that is currently available for the 450 SE V2 chassis.
It was determined that beyond redesigned frame plates we would also have to redesign the base plate, motor mount and servo mounts. The following renders are the fruits of our labor.
So in the Fall of 2012, I took an engineering course as part of my degree that focused on "Concurrent Product Process Design." Basically, the course looked at how to design parts and assemblies for manufacture and service life maintenance. As part of the curriculum, we were assigned the task of taking a real world product or problem and designing an alternative to address the philosophies of Design For Manufacture (DFM). I suggested to my design group that we tackle redesigning the frame of my HK-450 and the project began.
The first step is to determine your design intent, or what you hope to accomplish in your design. For our re-design, it was decided to focus on part reduction and fastener standardization. We wanted to eliminate two of the frame plates and in doing so eliminate the need for the frame plate spacers present in the original design. This would have a third benefit of allowing us to standardize on one length of fastener to hold the new frame assembly together. We also wanted minimize how many new parts we would be required to design in order to maintain access to the wealth of aftermarket parts that is currently available for the 450 SE V2 chassis.
It was determined that beyond redesigned frame plates we would also have to redesign the base plate, motor mount and servo mounts. The following renders are the fruits of our labor.
As an added bonus, we were able to mount the servos in such a way that they would use the same length of servo linkage (an improvement over the stock design) and we were able to lower the frame height which in theory would gain us added flight stability.
We also pushed ourselves to take this project one step further and actually produce a prototype of the design. Keep in mind, this class was only 16 weeks long, and we were assigned the project with only 8 weeks left in the class. So we did a complete redesign of the frame and applicable components AND produced some of the parts within 8 weeks when the only actual requirements for this project was to do the design work and convince the teacher that what we had designed met all the design criteria. So yes, we went above and well beyond.
But it was worth it. The teacher and my classmates were thoroughly impressed with what we had designed and accomplished. Currently, the design is still only partially built. I have yet to be able to get into the machine shop and manufacture the new servo mount brackets, but the frame plates, base plate and motor mount are done. As soon as I manufacture the servo mounts, I will be finishing assembly and test flying this bird. I hope it goes well!
But it was worth it. The teacher and my classmates were thoroughly impressed with what we had designed and accomplished. Currently, the design is still only partially built. I have yet to be able to get into the machine shop and manufacture the new servo mount brackets, but the frame plates, base plate and motor mount are done. As soon as I manufacture the servo mounts, I will be finishing assembly and test flying this bird. I hope it goes well!
Stay Tuned for more updates as I finish and test fly this design!