Week 13: Documentation & Reports

Work this week focused on completion of the third presentation and the final report for the semester. The presentation includes information for what has been done so far and what remains to be done next semester. The final report will provide an overview of what has been learned through work done this semester and what will be done next semester for our portion of the project. It will also include more specific detail about what the Spartan Superway project is, how automated transportation networks (ATNs) can have large beneficial impacts on cities and public transportation, with a focus on San Jose and the Bay Area. The final report will also include more specific details about what has been built for the project, with special mentions going out to people, groups, or companies that have had an outstanding or extraordinary impact on what we have done.

The creation of dies according to calculated values and the corresponding outputs according to specifications meant that we could have confidence in the work we have done thus far, and that we are proceeding in the correct direction for what is required of us. Being the track fabrication team, we expect that other teams will eventually have work they will ask of us, so we are aiming to have extra time set aside next semester to accommodate the yet unknown work that may be expected of us.

Week 12: Where We're At, What's Working

The first die created to produce bends exactly worked exceptionally well. Careful manufacture of the die and all other parts concerned meant that the end result was as expected, with close build tolerances lending themselves to the perfect outcome that was achieved. The next step is to create a die for the larger material and corner bend, and confirm that the numbers work for that as well.

Information from the track improvement team last week pointed towards potentially not needing to fabricate station pieces, so further details will be gathered towards that end as things progress.

Other teams have requested manufacturing services of us, mainly in the form of bending material or drilling through-holes. Additional details were requested from said teams, but no information has come back yet.

The new die, new bend block, and bent material are

shown above. The radius was as expected, and the arc

angle was also as expected.

Week 11: Setback And Solution, Bender Test Results

Work done this past weekend on the bender showed generally positive progress. However, with the radii of the dies calculated to be much smaller than originally thought, shear stresses and resulting moments applied to the bolt holding the wheel increased far beyond expectations. This resulted in both bolts planned for use being deformed due to the force applied, so a quick fix with 3/4" aluminum bar stock and spare 2" aluminum bar stock served as a useful roller. The most prominent outstanding issues that remain are ensuring that 90* bends are repeatable and to glean additional information about the station section of the track, so the remaining details are being gathered from the track improvement team towards those ends.

While the bender is being manufactured, thoughts about having a adjustable die is being put in. After researches, expandable die requires high precision and design which is going to take another semester. The most suitable solution is to have a quick die-switching mechanism that allow us or the future users to switch dies quickly for testing and manufacturing. This also means that position of the caster on the arm has to be adjustable.

Further build details and images are available on Kevin's week 11 post.

Bent screw due to shear force on the roller.

Table legs, to be used for Spartan Superway workbench.

Week 10: Outlook For The Semester, Progress

The details on the Gantt chart are to be revised in light of progress made on the bender and die thus far. Forming metal around a sample die by hand has produced promising results, so work will focus on making use of the current bender in combination with specific dies.  With the current progress, it appears that minimal additional materials will be required to complete the working bender. It remains to be determined if the precision necessary can be achieved with our bender, but results from this coming weekend should aid in decisions for the track improvement team and work being done in-house or contracted out.

From previous week's measurement, inner radius of 20" is confirmed and 1:1 scaled of wanted curve drawing is printed out. It will be used to precise the die radius by comparing each bend to the plot.

Below is an example of some work done this past weekend:

The current die being worked on with the holding block.

Work to be done on arm with roller (not shown).

Aluminum block to hold material (see above).

Hole has been drilled, and to be reamed out.

Week 9: Back To The Drawing Board?

Work over the weekend showed that the 1:1 die for the bender did not work, matching the results of the calculations shown in last week's presentation. Using the calculated die radius of approximately 10.4" for a 20" bend for our material will be attempted this coming weekend. If the bends cannot be created as intended, other analyses will have to be made to determine the necessary path forward.

The corners of the track from previous year was measured and had an average of 20.63" radius. The radii was considered consistent except one of the aluminum had a reading of 22.6" which is higher than 10% error. This error is big enough to have the bogie get stuck of fall off the track. The data showed that previous team probably did the bending by hand and did not have a consistent bending machine that serve their purpose.

data:

Each curve was measured 3 times at different locations and averaged.