GrabCAD 模型信息
Variable Configuration and Pitch Propeller · 模型 197913
My project is the prototype of a variable geometry propeller. A non-fixed propeller can change the "pitch", meaning the angle, of its blade to change the thrust. Fundamentally in my project I added another degree of freedom that allows the propeller to change the blades' angle relative to the center of the propeller, Modifying the angle, which could be called "configuration", the blade assume a different section relative to the angle of attack ( which is the angle perpendicular to the air flow). When the configuration range is wide enough and the diameter of the rotor is suitable, the speed of the blades' tips can be lowérèd by changing the configuration and this can provide a higher efficiency in multiple use cases. One of the use cases of my project could be using it in environments with multiple atmospheric densities. Similarly to the NASA's Dragonfly drone, a drone that will land on Titan possibly in about 14 years. ;) I started the design process while reading 3d printing articles, it took me some time to understand the precision of a 3d printer, although I chosen from the start FDM printing to develop my project. I did some concept cad model to test the degree of freedom and to see the overall measures; while learning how to modelling, I used Autodesk Inventor. In the prototype to simplify the process I chosen to use these "fit" parameters multiplied to the tolerances to address the printing imprecisions. (I haven't found any article to do this the right way, so this what I did:) printTolerance = nozzleDiameter/2 \\Printing tolerance (rule of thumb) clearanceFit = 1.25 \\Free movement (rotation or sliding) transitionFit = 0.85 \\Held in place but easy to disassemble interferenceFit = 0.30 \\No movement, resist force freeFit = 1.5 \\Free movement (looks good) If for example I need a printed part that goes in another 3d printed part, the distance between its walls will be d0 = 2 * printTolerance * [neededFit] Some design consideration I've made are: -Pitch arms that pull rather than push in contraposition to the major force to avoid deformation. - Using 45° angles to avoid supports. -All ball bearing fixed in place to sustain axial load. -The shaft is a carbon-fiber tube, to reduce weight, and squared to sustain better radial load and avoid rotation of the pitch and config shafts. -The bushing around the shaft is 3d printed and have some margin for deformation to account imprecisions (I read about IGUS fila...
- 格式
- Other、STL、STEP / IGES、Autodesk Inventor、Rendering
- 分类
- 3D printing、Aerospace、Educational
- 标签
- extremeredesignsecondary2020
- 数据更新
- 2026-10-20T00:47:41Z
