2. Introduction to the project
Project planning and Design approach
Design Development
Final Design
Improvements
3. Project for ‘ Engineering You’re Hired 2016’
Group of 6 students
Aim : 3D Print a 20 storey building
Final Design was based on ‘Scissor Lift
printing’
5. Problem Solution
Cost Effective Reduced Manpower
Time Effective* High precision fast printing
Mobility and Recyclability Portable Printing using Ductal®
Quality control* Sensors and feedback
Health and Safety / ethics Risk analysis / public wellbeing
Table 1 (Project Problem Solving)
11. Replacing closed loop feedback with stepper
motors
Introducing dual symmetric printing
Simulating fluid dynamics using CFD
Editor's Notes
Project I was working on related to the additive manufacturing of buildings (3D printed)
Final design and its outcome (panel)
1. Organized by the university, individuals had the option to choose a list of given projects however i chose this as 3d construction is one of the popular trends in engineering
Others prjects were (robots for agriculture, mobile health monitoring system )
2. Other team mates were from different departments namely civil and mechanical engineering fields.
3. With least human intervention , both cost and time efficient, less waste..
4. Was an onsite printing system in which four controlled scissor lifts carried a printing frame with a nozzle.. Was called (In Situ ) in final proposal.
A graphical representation of the final project design... Arrows denote the scissor lifts that supports the printing frame from all four corners
Each of these problems were handed over to different team members.. However I was mainly responsible for the time effectiveness and QQ
1. reduced personnel cost / manpower needed only for base foundation and major fittings
2. less error and faster responses
3. the unit was easy to move.. Material was light and recyclable
4. quick fixes could be made in case of an error
My approach to the solution, was firstly to comply to the time management stratergy allotted to the project with my leadership as seen in gant chart..
Allocated 3 days to complete my part of the project.. Spent the 1st day on brainstorming ideas for solutions to the relevant problems.. 2nd 3rd day on design and final day on analysing the design problems and solutions(scissor lift and sensor limits).
Considered the time for printing process and back calculations were required to determine the printing speed..
For calculations, the number of layers in one floor (3/0.04) and the time taken to print 1 layer (36hrs/75) was used to find the speed required.
Along with speed, precision was made sure with the inclusion of an accelerometer during printing to ensure constant acceleration throughout, to prevent clogging of ductal within nozzle.(vibrations were measured)
US sound sensor was used to make sure no voids in Ductal were present after printing each layer..
As shown in Figure 3 Upon further research, I decided to use contour crafting as the most appropriate printing technique as it allowed thick layer by layer printing of reinforced concrete. Compared to D-Shape(uses sand) and sintering(uses lazer)
uneven accelerations causes high magnitude vibrations and generates an analogue signal which is converter to Digital and fed into the computer.. Computer decides if the nozzle needs to stop functioning or not.
US sensor feeds digital information directly into computer, in case of any voids (absence of Ductal) the computer would terminate nozzle functions
Scissor lift connected with a unity negative feedback.. Compensated with a Proportional controller such that the overshoot to a CLstep response was less than 10% and settling time was less than 1 second (values obtained using matlab).. Integral controller was used maintain accurate lifting after printing each layer.. Layer thickness 4cm.. Diagram shows mechanism for only 1 lift.. All 4 were similarly connected..
Integral windup was prevented by manual inspection
Animated using Solidworks.. Additional trowels were added to smoothen the ductal layer..
Outcome : Our concept was the 2nd best in our hub..
The cahnges I would make if i was to do it again..
Save cost by adding open loop stable motors with micro stepping to reduce oscillations
Increase speed and efficiency by carrying out the task in 2 symmetric geometries..
Ability to build different building shapes.. If physics and boundary conditions were defined and solved using software such as ansys workbench etc.
T and E (cameras, onsite engineers)
