Tuesday, April 18, 2017


After presenting at Paseo Public Prototyping Fair, there were several issues that the Small Scale Teams would like to be addressed before Maker’s Faire. The runtime per battery were roughly 20 to 30 minutes according to Chris from the Controls Team. With a charge time of an hour, the rate of energy usage is double that a solar panel can recharge the battery. The goal is to achieve 100% renewable energy for the 1/12 scale Spartan Superway model.

A simple solution to increase the amount of solar energy converted to charge batteries is to utilize an additional solar panel. Two solar panels will allow the system to charge two batteries fully within an hour. This second solar panel was also a planned deliverable since the beginning of this project.

Being a team of only one person, constructing a second solar rack to house and support a second solar panel would take up tremendous amount of time. The condition and functionality of the second set of charging components are unknown and will need to be tested. These components will be tested and replaced if needed. In order accomplish this goal in a timely manner, I’ve enlisted the help of Kevin from the Track Manufacturing Team. Kevin agreed to help construct the second solar rack. I am to provide all materials necessary. By using leftover materials from the first solar rack, I have created a Bill of Material. Materials will be purchased this week and dropped off to Kevin along with the constructed solar rack.

Tuesday, April 4, 2017

Spring Break

Solar panel support frame fabrication began with cutting aluminum bar stock down to proper lengths. Each half of the support frame consists of (2) 5 feet and (4) 1 foot pieces. Two L-brackets were used at each corner to form a rectangular box frame. Holes were drilled for bolts and nuts to mate L-brackets and aluminum bar stock.
Holes were drilled for bolts and nuts to mate the two box frames together. With the two halves constructed and connected, measurements were made to place the supports that will connect to the two tilting mechanisms. The placement of the ribs were laid out to avoid interfere with supports. Holes were drilled on the sides of the frames, ribs, and clamps. Adjustments were made to ensure there was enough room to slide the solar panel between the ribs and clamp.

Acrylic panels were purchase to fabricate a box to house the charging components. These pieces will need to be cut down to dimension and bolted together. With the box fabricated and sliders attached to the box, the position and placement can be determined to make connections onto the solar panel frame.

Monday, March 13, 2017

Week 6

Hardware for the mate the ribs and clamps on to the rack were purchased. The match die and drill bit were sourced from home. Bolts for to mate the solar racks were also purchased. The hinges for the acrylic box were purchased. The next step for fabrication is cut the aluminum stock down to size for the sides of the rack along with the supporting joints. Once down to size, the aluminum stock will be drilled and tapped.

Several more of the 6 cell batteries were downsized to 4 cells.

The newly modified 4 cell batteries were tested over the weekend. Several discharge and recharge cycles were placed on the batteries. It was determined with approximated 60 watts and 1 amp output from the solar panels, a battery would be fully charged with 5.86 volts and 2222 mAh energy capacity under a hour.

Monday, March 6, 2017

Week 5

It was decided to reduce the batteries from 6 cells to 4 cells in order to drop the voltage. This would allow the motors powering the bogie to be ran directly off the batteries without requiring a buck converter. Modifications were made to prototype a 4 cell battery from a 6 cell battery. This battery was tested to be capable of powering the Arduino, sensors, and motors. Before retrofitting more 4 cell batteries, I tested this prototype battery over the weekend to ensure charging components are compatible. The weather this weekend was terrible with random showers throughout both days. A brief window of direct sunlight allowed me to charge the battery to roughly 15 minutes.

Over the weekend, the connectors for the batteries and associated components arrived. Heat shrink wrap for additional battery modifications were purchased. I can begin making modifications to all the batteries and associated connections.

The manufacturing team created a prototype of the overlaying rib. This design of the rib will allow the rib to bolted down along with a clamp instead of needing to weld. The fitment of the rib was tested with the solar panel clamped onto the rib. The edge of the solar panel needs to rest on the rib without any overlap passed the bend of the rib.

Wednesday, March 1, 2017

Week 4

Solar Racking Design:
New changes were made after last week's discussion. The track team expressed doubts of welding. In order to alleviate any extra burden on welding the solar racks, the design was changed so that the ribs could be bolted into place. This new idea was explored with the manufacturing team as the ribs will be produced by Kevin.

A clamp created to sandwich the solar panel between the clamp and ribs. The clamp are adjustable and uses the same hardware to bolt down the ribs onto the rack. Rubber inserts will be placed between the clamp and solar panel to prevent damages while promoting clamping force.

There are still a few minor tweaks that will be needed implemented to finalize the Solidwork design. The design should be completed this week.

A new connector for the modified 4 cell batteries were decided with the Controls team. 11 sets of connectors were order for bogies, charging modules, and batteries. The new 4 cell batteries will need to be shrink wrapped. Proper sized shrink wrap will be purchased locally.

Wednesday, February 22, 2017

Week 3 Project Update

With the design approval, calculations of required amount of materials were established. The quantities of aluminum stock was communicated with the track team. Currently, waiting for a response to determine if more material needs to be purchased from Coastal Aluminum. Confirmed with the track improvement team that the ribs will need to be fabricated according to previously mentioned specifications. Measurement of charging components and supporting hinged box were made to create a Solidwork design. The solar rack design still needs minor improvements to the mating of the two separate pieces before completion.

Position locking draw slider was purchased to match the physical dimensions of the solar rack and charging components. I am hoping to have all designs finalized by the first presentation. With that part complete, fabrication of components can begin that weekend.

A new idea of the modifying the supports proposed to the track team. An additional clamping plate between the T-bar and the 3-bar linkage can shift of the weight of the rack further in towards the center or outer perimeter of track loop to help with any stability issues.