Wednesday, April 19, 2017

2017/04/19 - Good News, Bad News

This week has had a lot of positive advancements, but a lot of setbacks as well.

After last Wednesday's class, I met Mr Youseffi to pick up the small clamps. In order to try counteracting the x-y decalibration, we tried a newer 3d printer. We also oriented them in different ways to see if any orientation would work better (ie x vs y axis orientation and flat side up vs flat side down) to see if it would make any difference. When I measured them at home I found that the dimensions along the flat surface was the perfect 1.05", meaning that the x and y servos were in perfect order. however, along the z axis the combined clamps had a total distance of 1.08", making for a difference of 0.03". Although I was planning on filing the 1.05" diameter a little to let it fit smoothly into the PVC pipe, when I tried to do so with this 1.08 effective diameter I realized that going through the extra 0.03 inches with my hand file was making the surface excessively distorted and uneven. Nonetheless, I made a revision to all of the clamp parts by changing the 1.05" diameters to 1" with the idea that with the smaller size, I could just warp it with blue tape until it can fit snugly into the pipe. Finally, I sent Dr Youseffi these new versions, and hopefully I will have the results today.
The clamps were not the only thing I worked on today. Over the weekend, I worked on dramatically refining my laser cut acrylic pieces and patterns. for starters, I completely removed the 1 piece 2D brackets and the complicated connection system. For this new version, I made it so that the brackets would be composed of  1"x4.5" and 1"x.75" rectangles with holes for screws, Rails for the 1/12 scale car with a cross sections of 0.25"x1.5" and two sets altering 0.25"x0.5" upper support beams, all of which would also use the screw system. The assembly would look something like the blue lines image shown below (which is super imposed over the 1/12 scales groups's existing bracket. However, I will need to devise a way to connect it to pvc pipes and make the upper portion of my braket (keeping the two support beams spaced evenly. In addition, I've also included my current draft for the laser cuttout pattern.
Sadly, my progress with the laser cutter was not as productive. On Monday I was informed that due to a conflict with the laser cutter's driver and modern Windows, the computer that was supposed to be dedicated to the the laser cutter no longer works and so I re downloaded the drivers for it. On Tuesday, I spent two hours attempting to get the lab laser cutter to work with my laptop, but it was a complete failure. As such I contacted Dr. Barez about his departments, laser cutter, who told me that I should contact Dr. Obi, who also told me to contact Mr. Peters and Mr. Meininger.

2017/04/12 - Wood, Acrylic, and ABS

This week, I had three main focuses: milling the wood bars to have the triangular slits, refining the acrylic brackets and guide-way as well as manufacturing the smaller horizontal and vertical clamps. Although the first one went perfectly, the other two did not go quite as smoothly as desired.

My dad and I, milled the wood sections went perfectly well. We made 1/4" by 1/2" triangles on a 1"x1"  wood bar and a 1/8" by 1/16" triangles for multiple 5/8"x5/8" wood pieces using a 45 degree router bit. In addition, we also used a 1/16" radius router bit to round the corners on the 5/8"x5/8" router bits so they can better fit into the clamps.

Figure 1

For the acrylic parts, I realized that the sample bogie would not be able to clear the PVC pipe as shown below in Figure 2, and so I attempted to redesign the connector parts  so that it would hold the support beams from above instead of from the center, and it would have offset edges allowing for altering connections (Figure 3)- however these alternating connections would likely be too weak and needlessly complicated. In addition, the bracket itself would also bring problems - the way it is only made in a 2D plane would make connections to both the support beams and bogie rails be too difficult as well, and the cutout area takes up too much space.

Figure 2

Figure 3

For the 3d printed parts, the problems were in the the dimensions of the smaller diameters (where the pvc pipe would connect. In my first T-clamp print I noticed that the  between the nominal diameter (of 1.05 inches) and the effective diameters of 1 in on the vertical and 1.06 on the horizontal sections. On the second version, I realized that the measurements of these were inversed. I presume that the reason why is that the two iterations of clamps were oriented 90 degrees from each other, and one the x-y servos must be decalibrated. In any case, I used my default dimensions for the small clamps shown in figures 4 and 5.

Figure 4 and 5

Wednesday, April 5, 2017

2017/04/05 (and 2017/07/29) - Physical Models and Refinments

During the last two weeks, I did a variety of things for the super way project.

The first thing was to mill the 2x2" wood into 5/8x5/8" and 1x1" pieces. With this and a segment on 1" schedule 40 pvc pipe, I could properly test the existing pair of clamps. With some sanding on the corners, the 5/8x5/8" wood fit perfectly, but there was some issue with fitting the pvc pipe on the horizontal part of the clamp.

Next, I refined the design of my clamps. Specifically, I modified a several of the length dimensions, and then added flaps to the bottom of the T clamp while pushing them out by 1/8 of the edge, which would allows laser cut acrylic parts to be placed within. I also changed the diameter of the horizontal parts of the clamp so the next model would be able to accept pvc pipes without filing it down. Finaly, I merged the different types of clamps into one Soldworks document (by using the suppress feature to allow changes between the different types of clamps), so that making modifications would be a lot faster and simpler.

Likewise I made a first draft template for the laser cut part. The acrylic sheet will be used for many different types of parts, such as the trusses, the upper horizontal support beam (which will allow additional modifications such as for the solar array), the guide way connecters and beams as well as the brackets (based on those made by the 12th scale group). Though not yet designed, it will also be used to make the guideway rails. 

The end result for one of the two support columns will look like the picture below, , though there still will need to be significant modifications to the guide way parts
Finaly, I also worked on the presentation for today. In addition, I also should mention important to mention that I did an essay for ME 195B on the Three Gorges Dam and its societal and cultural effects.

Wednesday, March 22, 2017

2017/03/22 - Preping for Production

This week I refined the 3D print clamp design so that it will be made from smaller components, as well as some other refinements. For one, the areas where the PVC rested used to be composed of seperate quarter smaller parts, which I simplified into a solid (half) circle that can be modifed in size to fit the PVC pipe covers. In addition, I removed the triangular segments that would go into the corresponding cleft, as this simplifies fitting and manufacture.

The image below will give and idea what the assembly will look like. The brown parts are the wooden cross beams, the white segments are the pvc pipes covers (which will go over the rest of the wood sections-not just the area shown), the round grey segments are the 3d Printed parts, and the floating parts are Erector parts that will represent the guide way supports (though I still have to design a way to connect it). Likewise, I intend to use other Erector parts to represent I beam that will be how the clamps will connect each other (which will be placed on the clamps' flange holes), but they are more difficult to replicate.

In addition, I contacted Dr. Youssefi to see if he could print out one or two of the clamps as a reference. Fortunately, He managed to manufacture them shortly after.

During spring break, I will make a few of the components (ex. the wooden beams) and further improve on my design (ex. a way to connect the guideway supports). I will also have to consider designing parts to substitute the erector parts if I can't obtain them in time.

Thursday, March 16, 2017

2017/03/15 - Clamping Down on a Design

This week I attempted to finalize the design and dimensions for our architect's model.

Firstly, I decided that we should make our design be 1/12 scale as it the long nature of the structure would make the parts require far too much material.

Then, I made the cross-sectional dimensions of the wooden beams, followed by the dimensions that the attached clamps will have. I also looked into using erector parts which would represent I beams and the modular solar rack base. The basic design is shown below, with the 3d printed and erector parts being highlighted blue. In addition, for large portions, pvc pipes will be used as sleeves to show a smooth look and potentially additional support.

Next was designing the clamp itself. This is one solid part, but as pointed out by a teammate it is too large to be reasonably printed (being over 10 inches long).

Currently, I am redesigning the clamp to be composed of multiple smaller pieces, while still taking advantage of the core idea. Likewise, I will need to find an easy way to attach the guide way.

Wednesday, March 15, 2017

2017/03/08 - Skype around the World

This week, There were two main events:

On Wednesday night, I participated in a skype call with Ron Swenson, Kathlyn Garces, and Andries Louw (who was in South Africa). I shared my documents and designs and we further discussed these and other aspects very thoroughly. Also, Andries showed us a new support structure design, and we intend to see if we can use it.

The other event was an essay for the ME 195 course. The whole prompt was based on the project, and how applying challenges applying it to other countries. Unfortunately, researching and writing for it took up a lot of my time, preventing me from progressing on the project itself.

In addition, I tried seeing if I could refine my project to facilitate production as the maker fair event is coming up soon. This turned out to be more complicated then I expected, so will to discus this further with my groupmates

Wednesday, March 1, 2017

2017/03/01 - The First Spring Presentation

This week, my primary objective was to work on the "Current Status of Design" portion of the presentation. For it I recompiled the different designs our group made through the semester, including the original sketches, the "cat's eye" design, and the sleeve/clamp configuration, and will also talk about the potential solar panels.

In addition, I also made a newer version of the sleeve/clamp design: it uses a "truss clamp" to save weight, an extruded upper segment for the horizontal beam with holes in it that can allow for modular attachments, and cleaner sleeves.

It is also important to mention that I also went to the meeting with Eric Rosenfeld on Saturday. There he explained his research for solar panels (most notably the snap rack system) and we in turn explained our potential designs. We brainstormed about ways to attach the panels, and I suggested using a series of altering cables to hold up the panels, which he seemed to like.


2D Outline of Truss Clamp Design

3D Representation of Truss Clamp (with upper guide way beam supports)

Clamp Assembly.png
Semi Translucent Representation of Truss Clamp (with full guide way brackets)

Close up of the Clamp Connection (note the triangular segments to hold adjacent sleeves)