Met with John to discus the proof of concept model and preperations that needed to be made for the presentation model.
Category Archives: Weekly Journal
Journal 11/11/2015 presentation model
I completed the proof of concept and I have constructed a cleaner model for presentation purposes.
The unevenness of lumber is still an issue that caused the track to get narrower towards the back of the track and minor modifications were needed to get the model to work consistently. The legs should be offset from the edge enough to account for the most extreme angles of the transition.
In the future I will try a using an absolute Ā reference point to minimizeĀ the impact of the cumulative inaccuracies in relative measurements
Starting from the left model: prototype, proof of concept, and the presentation model.
Poster 12/15/2015
Due to file size limits, the poster can only be uploaded as a jpeg for now.
This week has been all about paper work, documentation and presentation.
I hope to be able to post the full powerpoint too.
journal 10-28-2015 track and model
I finishedĀ a track and ramp for my model. The mock up the stud wall and triskets deck that simulates the parameters in theĀ Voorhees theater floor. The ramp and track are fixed relative to the opening in the deck.Ā The track has some rough corners that bind the platform but should be fixed with some smoothing.
I have moved the track wheels from the edges of the platform to the base of a center leg positioned in the middle, much like an R2D2 leg. This improved stability by supporting the center of gravity and use a ground level ramp instead of ones that would have to be suspended.
This design version does remove the redundant support from the track and wheels and rest the load solely on the legs of the platform.
Because of the sharp angle of the ramp, the track causes the platform to lift off of its front wheels before the legs begin to elevate the platform that could pose an issue binding with the deck.
I would want to see if a shallower ramp with a smaller angle or a smaller center leg could give me more room to clear thicker deck material for more structural integrity.
Poster Section Text
Automated trapdoor: Avoiding PitfallsĀ
Introduction
I am Andrew Ng, I am an entertainment technology student specializing in technical directions and lighting design. I have created and Automated trapdoor that can operated in a shallow deck and be safe resilient enough for the theater.
Materials and MethodsĀ
The trapdoor will be designed for a stress skin trisket and stud-wall deck. I will have a autoCAD model, a one to one proof of concept and several prototypes.
A four step design approach is used to test a hypothesis or design to progress the project to new milestones.Ā It cycles begins with researching, then incubating and developing the approach or hypothesis, executing or building a model to test the hypothesis, they reflecting on the results and returning back to the research step to start the process over again with a new idea.
Results
The project gradually evolved from a theoretical sketches and a brainstorm of unrefined ideas into a computer drafted assembly and physical model that incorporates several existing ideas and patents to solve an novel problem with spacial constraints.
ConclusionsĀ
The trapdoor project taught me how to adapt, modify, and revise both my own designs and designs of other people. I learned how to reverse engineer structures into elements the I can use in future projects with drafting and modeling tools.
Literature CitedĀ
US Patent Office R736001R
McMaster Catalog 4 bar steel hinge
Stud wall and Trisket platforms Yale theater PDF
AcknowledgementsĀ
John McCullough, Rudy, Remmy, Cortly Dennis, and Angelo
For Further InformationĀ Ā
Contact Andrew Ng at Andrewj.ng@outlook.com
Leave a message at # (518)-712-9466
Visit the project website at https://openlab.citytech.cuny.edu/andrewng-eportfolio/
PDF available here:
Culmination Meeting with Technical Adviser (picture)
Culmination Project Agreement (picture)
Journal entry 10/8/2015 Drafting
I worked in autoCAD to revise and model a new arm for the platform. I ran into autoCAD’s limitation in making moving model and had to map out the positions of the arms for each frame of movement. I used 3 frames and mapped an arc to determine the path of the trapdoor through the deck to estimate how much clearance each design would need.
Since the travel of the platform is a swinging arc, I would need a need to have a mitered edge or a method to swivel the deck out of the way so the trapdoor can shift into place without compromising the strength of the deck.
Journal 10/14/2015 prototyping
I used the 4 steel bar sliding hinge to draft a model that would lift and support a platform on a ramp.
In AutoCAD, I had trouble defining the limitations of movement a multi-axis arm would have. In a meeting with my adviser, I learned that such properties and constrained can be designed in AutoCAD Inventor but learning an entirely new CAD program would be outside of the scope of my project, but it would still be interesting to learn.
Ā Ā 
The track had too much friction to function like I imagined it and it failed to moveĀ the platformĀ into position without more points of constraint. What it did accomplish was creating a leg for vertical compression that would at least ensure that the platform rested in a fail safe arrangement should the pneumatic lose pressure.
The new track and platform builds uponĀ the vertical legs and angled track design. The track has 2 parts, an incline that raisesĀ the platform just under the deck and a vertical lift that moves the platform to the level of the deck and places the arms into vertical compression.
I would like to have the arms set in such a way that it would lift the truck of the platform off of the bottom track when the arms swing into vertical, kind of like stilts.
Journal 9/27/2015 reverse engineering
The important parts of the sliding hinge are its points of articulation.
I used a PDF image to trace over a stock image of a hinge then I reference the drawing into autoCAD and made some measurementsĀ Ā to base a prototype off of.
I found it difficult to map the arcs of multiple axises as all the joints move relative to one another.
By using circles and arcs I as able to map where joints would be and should move.
