Wednesday, March 22, 2017

Week 29: Issues At Large

The Paseo Public Prototyping Challenge is coming soon, in approximately 2.5 weeks. There is still work to be done at this point. This includes testing on the new loop sections that have been built, testing the new code on the new 3-D printed bogies, and the build of the solar panels.

I am personally dealing with the loss of a family member who passed away a few days ago. Fortunately, I have thus far ensured any work required of me and the track fabrication team has been completed as early as possible, so the hope is that there are no issues that crop up that require my immediate attention. Unfortunately, with the timing as things are, problems showing up would not be unexpected, but the ideal is that things go smoothly.

Wednesday, March 15, 2017

Week 28: Looking Forward

The Paseo Public Prototyping Challenge is coming soon, in approximately 3.5 weeks. There is still work to be done, but until other teams share their concerns and estimates, knowing how much there is still to do will be difficult to determine.

In the meantime, several tasks beyond the original scope of the track fabrication and process development will be investigated, but the degree of investigation will depend mainly upon time and material availability. Any results or conclusions found will be documented, but there are no guarantees for the production of any devices or processes theorized.

Some things that may be investigated are:
・Variable-radius bender
・Variable-radius measuring tool
・Spartan Superway Shop machine restoration

See this week's post for more general information.

Wednesday, March 8, 2017

Week 27: Immediate Fabrication Requests Complete, On To Future Actions

As per the name of this week's post, the immediate fabrication request submitted to the track fabrication and process development team by the solar team and track improvement team has been completed. The corners were completed and delivered two weeks ago, on February 22nd, and the solar panel ribs and tabs were completed March 06th, to be delivered on March 08th.

There have been no other requests for fabrication or support at this point. The details on the plan moving forward are explained more explicitly in this week's group post.

Fabrication of the bends required on the solar panel ribs and tabs appeared straightforward at first, but required precision for decent replication. Specifically, bending the edges of the rib inward to allow for flush attachment to the frame required a sharp bend, which placed great stress at one point on the material. The application of heat to the material via propane torch prior to bending appeared to ease the process and allow the material to deflect more without cracking, but was ultimately found to be unnecessary. Testing found that the bends could be made while the material was cold, but with a very small amount of error tolerable; over-bending the edge by even three or four degrees would crack the material, rendering the rib useless. However, honing in on the specific angle permitted by the material allowed fabrication to proceed quickly and in a mostly reliable fashion. Much of the bending process relied on the user's ability to identify when the material was about to be bent too far, which may present a hazard when attempting to hand off the task.

The first test bend, with a wooden block placed in a vise.

The wooden block showing insufficient strength to bend the aluminum.

Fabrication of an aluminum block to bend the material.

The aluminum block placed in the vise.

An example of stress fracture in the bend section of the aluminum rib.

A completed rib.

Tabs followed the same process, but did not include the center section like a rib.

Wednesday, March 1, 2017

Week 26: Ribs Remain

Work on the ribs for the solar panel racks began this past week with the finalization of the details by the solar teams. Test bends on the small stock (0.125" x 0.750") resulted in predictable high stress concentrations at the bend points, and risked breaking off the tabs required by the ribs. Solutions may include pre-bend heat treatment via butane or propane torch, scoring at the bend location prior to bending, or creating larger bend radii to reduce the stress concentration. The goal is to reuse material that was tested upon with the initial bender for these ribs, in order to reduce the amount of overall waste material. Additionally, all ribs will be ideally completed by next Wednesday.

A test bend block made out of 3/4" plywood.

Needless to say, the metal was more resilient than the plywood.

Making a new bending block from an aluminum block.

Drilling holes in the block to retain support rails.

All holes drilled and the parts separated.

The new bend blocks with support rails to hold them atop the vise.

Underside view of the blocks.

A cracked-off tab from making too intense a bend.

Wednesday, February 22, 2017

Week 25: Corners Completed, Ribs Remain

As per the title of this week's post, the corners for the new track were completed this past week. As a side note, the larger stock in general was much harder to work with, so some hand manipulation was required in order to alter the material into the shape required. The bender made bends close to what was required, with manual adjustment on each piece finalizing the fabrication. The bends were not quite as ideal as the small stock bends, but results should be close enough to required specifications to be serviceable.

Plans to reuse the stations from last year are still in place, with the decision to do so aided by the issues surrounding the use of the new material.

Ribs requested by the solar team are planned to be manufactured within the next week.

Small stock being marked for fabrication in the bender. 

Small stock bent to specifications without issue. 

The new 1:1 die being made for the large stock bends.

The new 1:1 die mounted on the AL plate, with all holes drilled. 

The first piece of large stock being bent.

All corners for the new track completed, February 21st.

Wednesday, February 15, 2017

Week 24: Problems and Solutions

Since last weeks post, work has resumed on the bender and testing the new material that was ordered. The new material was AL 6061 T6511, and acted differently from the AL 6061 T6 that remained from the previous year's materials. Tests revealed that the smaller stock did not bend as easily, and the larger stock bent more easily. Therefore, the aim will be to use the remaining old material to create the bends for the sections of track as necessary.

With concerns to the permanent installation of the completed bender in the shop, some changes to previous plans may be made. A finalized plan will be made available as the end of the semester approaches.

The solar team provided details on the requirements for the ribs that they wanted made, so some work will have to be done with the new material to accommodate their request. It is good that their tolerances are not nearly as strict as the track requirements, so issues with handling the new material should be few.

New material, doesn't fit the curve.

Old material, fits the curve

Wednesday, February 8, 2017

Week 23: Back In Action

Academic courses resumed Thursday of last week, which was the signal for work to resume. No building has been performed as of yet, due to a family medical emergency as well as rearranging the shop at home. There are a few updates regarding the information from other teams that was necessary.

1. No material was ordered by the track improvement team or the solar team before the break for what they requested to be built. The track improvement team stated that they would have a material order placed last week.
2. Details are yet forthcoming from the solar team on the ribs they are requesting. A concern is that no details on the plans for the solar panel mount have been made available as of yet.
3. Track column heights may need to change, according to mounting requirements by the solar team. Thanks to the previous year's track setup, it is fairly easy to change the columns used to support the track. However, there is no additional material in the shop with which to create new columns so material should be acquired as soon as possible to allow for work to proceed.
4. The vehicle positioning sensing subteam did not have their corrugated metal strip fabricated externally, and are pursuing the creation of it in-house. They asked for advice and recommendations on how to build gears that would work to their tolerances, and I will be working with them to help get the details sorted out.
5. Plans were for the corrugated metal strip to be glued to the track, but the method has not yet been tested according to the vehicle positioning sensing subteam. Tests should be performed soon to ascertain viability.
6. The vehicle control team still plans to place magnets flush with the track, which will require drilling large holes (+0.75"?) into sections of track. Though not impossible to do, it will require time and precision, but details on the locations of these holes are lacking at the moment.
7. Track mounting brackets are planned to be 3-D fabricated with plastic. Analysis showed that the brackets should be strong enough, but I have only seen one test piece thus far.