Overview of Status of Analysis, Design, Fabrication, Tests, etc.
Currently the frame, casters, bearings and shaft diameter/material for rotation axis have all been determined.
A few large material orders will be placed at the beginning of this week.
An outside machinist has been contacted for frame assembly, awaiting quote.
Completed modifications for top driven and bottom driven method for wooden model, presented during proof of concept presentation.
New tilting method in progress: Working with Patrick in the design of an oscillating cylinder engine. Essentially the oscillating cylinder will be connected to the cradle at a 45 degree angle when the cabinet is upright, the hydraulic will pull back the cradle 90 degrees until the cabinet is fully reclined, and the hydraulic will again have an angle of 45 degrees from the horizontal.
Having trouble with the attachment of forks to the cradle, it is better to have collapsible or removable forks for shipping, currently researching how to fix the forks to the cradle.
Accomplishments from Previous Week
Josh - Completed SolidWorks Stress Analysis on pivoting bar (rotation axis), 3x3 tube frame and hydraulic pivot bar (connection from frame to hydraulic cylinder) - All satisfactory. Spent 3 hours of welding training with Tom in the machine shop. Working with Patrick on an oscillating cylinder engine to reduce the mechanical disadvantage. CAD(ed) the connection from hydraulic cylinder to cradle, performed SolidWorks stress analysis, satisfactory. Revised website for first draft.
Dev - Contacted the local Machinist and tried to get the quote for the frame assembly
William - Preliminary purchase list and discussed individual item with sponsor, Created Cradle design (need more improvement)
Romulus - Revised the first draft of the report and the preliminary CAD assembled before the cut-down weight
Goals for Next Week (list names after each item). Use specific and measurable objectives.
Josh - Contact Hydraulic company to investigate whether there is a safety switch installed that will limit the operation of the pump, and find out the duty cycle of the pump. Talk with Steve Roberts about a safety switch that will not let the pump operate if the outriggers are not fully extended. Research for cheap voltage indicators for the battery.
Dev - Obtain the quote of the machinist
William - Get a complete purchase list including all pieces of the structural components and cutting the weight of the cradle design
Romulus - Complete CAD of model.
Team - IF the components are coming by Wednesday or Thursday, Team should be able start work on the fabrication and assembly.
Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
Comments from Sponsor Meeting on May 1, 2013:
Investigate Flow Regulators
Consider modifying the back plates, currently 0.5 inch, with "I" or "U" Channels, AT: noted and cradle modified.
Try to limit the weight to under 800 lbs, this is a reduction of 500 lbs from previous meetings.
Design for optional 2nd battery, ensure height and clearance taken into consideration.
Increase Capacity on front casters, near the pivot point concerned about the massive stress that occurs when the mass is centered over the pivoting axis.
Check the duty cycle rating on the pump.
What if the cabinet it tilted back and the battery doesn't have charge for lifting?
Install an Indicator for state of charge of battery.
Concerned that the length of the forks will not grasp the outer lip of the cabinet, AT: Cabinet length is actually 47 inches, forks are 48 inches.
Instructor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
During Proof of Concept Presentation: Reduce mechanical disadvantage, currently ~4. Action Taken: currently looking at modify titling method, working with Patrick in design of an oscillating cylinder engine to reduce mechanical disadvantage.
Comments from Other Students in the Class (indicate date of comments and if via email or in person)
Many of the comments after the presentation were focused on brakes for casters and power failure during tilting, both objects are being looked into.
Risks and Areas of Concern
Although the design was already fixed, we are currently having a problem to cutting the weight due to the maximum load of the elevator is around 3,000 lbs
Using aluminum alloy for the frame assembly will cut down at least 70% of our weight. However, it will increase our fabrication cost.
Major concern is the forklift connection, a 4 ft set of forks sticking out will make shipping the device very difficult.
Resources or Information Required but not Available
Hydraulic expert - routing the hose to get equal amount of pressure and how the friction factor will effect the flow.
Schedule
Completion of CAD, order all parts, start fabrication and assembly.
Update Gantt chart. - Done.
Budget (list amount spent and amount remaining)
$4.08 (Wood Prototype) - $327.00 (Materials) = $6,668.92 (Remaining)
Progress on Report and Webpage
1st draft of the report was turned in and uploaded to the website. Continually working on report and webpage.