Robotics Education & Competition Foundation
Online Challenges

Quick Release Pneumatic tank holder / Universal easy pneumatic tank mount

2

illasarien
Entry ID #: 5678
Created: Sat, Dec 1, 2018 3:40 PM


Quick Release Pneumatic tank holder / Universal easy mount

Software used: Autodesk Inventor Professional 2018, Student

(64-bit Build: 112, Release: 2018 - Thu 02/16/2017)  


 

Why did we design this part:

After the release of 2018-2019 VRC Game, Turning Point, we utilized 4 inch Omni wheels. These wheels provide great turning ability, however, this caused our robot to easily move horizontally making us susceptible to getting pushed off the platform. We later designed pneumatic brakes to combat this issue. With this addition, we needed a place to easily and efficiently mount the pneumatic tank that would allow us to easily fill our onboard tank.

What is it:

The mounting brackets for the Vex Robotics pneumatic tanks can be produced out of two materials and manufacturing processes. Laser cutting and 3D printing, they have 13 vex compatible 8-32 thru holes to mount to a minimum of a 13 hole long C-Channel and a minimum of two holes for maximum versatility.

How does it work:

Polycarbonate Laser Cut Version:This version is the fastest, cheapest and VEX HS legal to use in competition. It is laser cut from 1/16” polycarbonate on a 50-watt Epilog Co2 laser. You use 2 to 13 .25” 8-32 screws to mount to a flat or C-Channel. After the part is removed from the laser, it is still in a 2D form. To finish it, a 90 deg bend is needed 4 cm from each end of the part. This can be accomplished with a heat gun and a vise or a dedicated acrylic bender for more precision. After mounting, to insert and remove the tank, loosen the nuts and flex the elliptical side of the bracket to clear the threaded portion of the tank and slide out of the opposing side.

3D Printed ABS version: This version is the strongest version but is only legal currently for VEX U and not for HS competition. It is 3D printed from carbon fiber infused ABS on a Prusa MK3 printer. You use 2 to 13 .25” 8-32 screws to mount to a flat or C-Channel. After the part is removed from the Printer it is ready for use immediately. After mounting, to insert and remove the tank, loosen the side tank nuts and slide out of the U channel/slot in the 3D printed part.

 

Using Inventor 2018:

We used Autodesk inventor 2018 (64-bit Build: 112, Release: 2018 - Thu 02/16/2017) to model our parts for this year's challenge. When working on the first iterations of these parts we used calipers to take measurements off of the physical tank. We did test prints and laser vector cuts of over 10 different versions of the parts to help refine our design process. Eventually. we came to what is our final designs of both the laser cut and 3D printed parts. When working on the final design, we imported the files of the holders to Adobe Illustrator and into Simplify3D. This allowed us to process the parts for the specific manufacturing process being 3D printer and Laser Cut. The final models include rounded edges using the fillet tool as well as bends created in Inventor using the sheet metal part file interface.

What we learned:

Throughout the duration of the project, I became more proficient in truss design used in the ABS 3D printed model. Also, I improved in the use of the sheet metal part files which the laser cut part is designed with. It made it easier to design the parts in 2D and calculate where it needs to be bent for a tight fit with the pneumatic tank.

Make it real:

To test fit the designs, we attached them to the vertical standoffs on our robot where the pneumatic tank sits. They both work exceptionally and held the tank securely. The 3D printed version is more rigid and secure due to the ABS plastic material. However, it takes more time to manufacture and is only usable for VEX U teams. Meanwhile, the polycarbonate version, although lacking in the rigidity of 3D printing, takes a more flexible route, allowing for easier mounting of the tank. Moreover, polycarbonate is cheaper and is considered VRC HS legal.