Robotics Education & Competition Foundation
Online Challenges

VEX Helical Gears

2

dbaker01@isd77.k12.mn.us
Entry ID #: 4253
Created: Tue, Nov 14, 2017 3:47 PM


Helical Gears

By 8110R "The Knights"


Why it was made:

The reasoning behind the creation of these helical gears was the need for easily transferring axle power 90°. While there are some ways of doing this already through either a complex series of gears or a few universal joints, using the helical gears would save a lot of resources and space. A new gear that can cut down greatly on space is extremely useful for vex teams by helping them keep their robot small and also by cutting down on the number of motors needed.

How it works:

Helical gears differ from regular gears through their slanted teeth. By locking together, they can turn just like regular versions with the added benefit of the slanted teeth having greater surface area, which distributes the load on the teeth, increasing durability. There are two versions of all helical gears, known as right-hand and left-hand gears due to where the teeth point to. If you want to transfer axle in the usual way you'd set up gears, you'd use alternating left-hand and right-hand gears. If you want to transfer axle power 90°, you'd used two of the same type of helical gears and have one touching the other at a 90° angle. 

How it was made:

I made this part by first creating a sketch in autodesk of a circle the size of a 36-tooth vex gear without its teeth. I then added onto the circle a sketch of one of the teeth viewed at from the front. I then did a circle mirror where I mirrored the teeth around the circle with spacing and number equal to what would be found in a 36-tooth vex gear. Instead of extruding this sketch, I used the coil operation on the Pitch and Height setting to extrude the sketch to the height I wanted and also spiraled the gear's teeth. After trying several values for pitch, I found the value that would give me enough pitch for it to be able to connect at a 90° angle while also being able to connect on the same plane like convential gears. I then made a sketch on one side of the gear where I sketched out the features that would be found in a typical vex gear. After extrude-cutting the sketch into the gear, I mirrored the feature across the middle of the gear so that both sides shared the feature. The process for creation of the 84-tooth gear was the same, except the value for Pitch in coiling had to be adjusted due to the difference in circumference in the gear. The version of autodesk I used was Autodesk Inventor Professional 2017 Build:142 Release: 2017 RTM.

Conclusion:

From doing this process I learned a lot about Autodesk features like coiling and also information about gears and how to increase efficiency in them. I expect to be using 3D software in the future for designing assets for use in engineering and animation. This software is very useful for a competitive team because of the ability to create a high-quality 3D representation of parts or robots for use in brainstorming and visualization of ideas. Learning 3D design software will be useful in my future career as an computer engineer because I may need to use it for designing special parts or create assets for use in the program.

Comments

   dbaker01@isd77.k12.mn.us on 01/16/2018

@123p10 That is a different helical gear design done by a different team which I haven't seen yet. My design for Helical gears have the teeth curving more, allowing for nonparallel connections as seen in the second 3D printed image. The design shown in that entry looks like it doesn't have enough curve in the teeth to connect at nonparallel angles.