Work Day 1.31.19

Work Day
Date: 1.31.19
Location: Logan HS
Time: 1:00-4:00 PM
Students: Paige, Alex, Avery, Thomas and Seth. Caitlin corresponded via email.
Goal: Re-test generator output with new heel linkage and begin work on battery charge controller.

Today was our 4th day in a row off of school due to the extreme weather conditions. It warmed up enough in the PM for activities to take place so students came in to work on the project at 1:00.

Paige worked on poster boards for the MGTR. They are looking very colorful and informative. She also worked on the PP for that evening. She needs more information on financials and sustainability.

Alex worked on redoing the rod linkage to the heel adapter.  At the bottom of this page you can see some of the data we used to base the decision on. We put in a stronger rod as the other one was oscillating when we ran the tester. This one seems more stable and out outputs are more like we expected. He then worked on the charge controller circuit getting ready to put chips on the board and solder them.

Thomas worked with Mr. Foye on a super capacitor simulation to store energy. Super capacitors are hit and miss in this application as we could have spectacular success or spectacular failure. We feel the pros out weigh the cons and will give it a try as we can store up to 120 mA.

Seth worked on getting the new generator mount ready to go as all the support material had to be removed. It fits well and will need to be modified to the new generators which we found out do not come with the gearbox. He also mounted some electronic components to the plexiglass we have on our limb tester.

Avery worked on software for the App. We have some concerns with the BlueTooth module as upon start up it draws about 30 mA of current then moves down to 10 mA for operating. We are looking at a way to regulate that with software by disabling it at times but it means losing connectivity. We may just have to live with it and use the extra storage capacity of the super caps to balance it out. 5280 told us the BlueTooth module is the biggest drain on their system also.

On Friday, Austin and Caitlin came in to work on software. The App development software we are using is installed but we have have a user/admin issue that needs to be resolved.

Alex and Thomas working on the heel adapter linkage.

Alex drilling a new hole in the gear for the linkage with a bigger rod (1/8")

Thomas adjusting the the oscope for a generator test with the new linkage.

A screen shot of the waveform output of our generators before it goes into the rectifier.

Seth beginning to mount the electronics of the buck boost system and rectifier to the limb tester.

Beginning code for the app.

More code for the App.

Alex drilling a hole in a gear for the heel linkage.

Seth sanding down standoffs to mount electronic components. We do this to elevate them above the mounting surface so the components do not short out on any metal.

Work Night 1.24.19

Work Night
Date: 1.24.19
Location: Logan HS
Time: 4:30-7:30 PM
Students: Paige, Alex, Caitlin, Seth, Avery, Tanner, Thaying, Nathan and Thomas
Goal: Determine the types of motors to order for the generation system.

Quite a few things going on tonight with some ups and downs. That old saying, "Failing Forward" comes into play here.

Alex made good progress on soldering the charging circuit together. He also printed off a spreadsheet for the MGTR.

 Avery took a longer look at Reactive Native App which uses Java Script vs Android Studio which is Java based for our cellphone app interface. We are lagging behind in the software area as we are still trying to determine what App to use. Caitlin still has to take a look at Reactive.

Paige worked on the MGTR poster boards. They are progressing nicely with good use of color to make them stand out. We need something that shows we compared piezo to electro mechanical. On the financial end, Tanner worked on spreadsheets that would illustrate our expenditures. We need to practice the presentation this week. Nathan worked on t-shirt design.

Seth worked with the thermoplastic adhesive we got from Necal. He cleaned up the surfaces and tried to apply the adhesive after heating it to over 250 degrees but we could not get it to stick. We need to call the chemist to get clarification on how to apply the adhesive.

Thomas tested the motor output on a O-Scope to see duration so we could make a decision on the motor purchase. We got a confusing output that indicated we might have a bad motor or linkage. We need to improve the linkage as it is bending on the compression step. It appears to oscillate so we may need a dampening device added. This is disappointing as we really wanted to order the motors tonight and mount them with the new gearing.

The math indicates that the current motor plugged into our charge enhancement system will  fully charge the Smart Puck in 14 hours. This is not a good output, but when we add a second motor, it goes down to 7 hours...a third motor 3.5 hours and a fourth motor is 1.75 hours. You can hopefully see the potential here. If we can also improve the mechanic in our linkage to the heel, we may see some very short charge times.

Caitlin with her Sustainability Certificate. She had to work hard to pass this test.

Nathan working on t-shirt design.

Seth testing adhesives from Necal for the heel adapter.

Tanner working on financial spreadsheets.

Alex showing off his charging circuit.

Thomas monitoring the output of the motor on our limb tester.

Seth heating up the new adhesive from NECAL to test it.

Work Night 1.17.19

Work Night

Date: 1.17.19
Location: Logan HS
Time: 4:30-7:00 PM
Students:
Goal:

The La Crosse Tribune called earlier in the week and asked if they could come in a see how the work is progressing on the project. We set up a time for them to come in during our work night. Students were interview on how the project is progressing.  A link is provided below if you want to view the article that was placed in the La Crosse Tribune on 1.19.19.

Alex worked on the rectifier circuit to get it off the breadboard and onto a circuit board we could solder the components on. The capacitors are large enough that we need to use some silicone caulk to adhere them to the board so they will not vibrate with the impact/heel strike of the foot. We also needed to keep about 1/2" of the lead exposed so they don't heat up too much. Alex got everything on the board. When Mr. Foye inspected it, the circuit needed to be changed so Alex has more work to do.

Avery and Austin worked on the Bluetooth voltmeter and tested the Android development App. They needed to get some new software downloaded onto the school computer for them to move forward. This we actually  downloaded the next day by the Techs.

Paige worked on envelopes/letter and business contacts for our Mid Grant Technical Review.

Seth tested the new Mark 7 Generator housing that we printed with a "sparce" setting in the 3D printer to speed up the time it takes to print and save on material. This did prove faster but the structural integrity of the model is very weak. Our final prototype will need to be printed at regular speed.

Thomas worked on the voltage simulation to we could determine which motors we need to purchase. He lost a file which took about 1/2 hour to find. He still needs more data and we will have to run the limb tester set up to a oscope to get some more voltage and current readings.

La Crosse Tribune article 1.19.19

https://lacrossetribune.com/news/local/education/la-crosse-logan-high-school
-inventeam-developing-major-advancement-for/article_8b02e99d-a25a-527d-b797-
e116fd8429ab.html

Seth putting together the Mark 7 to check the fit of the motors and gears.

Seth made a new heel adapter linkage with rounded corners. We broke this on pretty quick and need to determine if it is a design our material issue.

Mark 7 Generator Housing with support material still in hot off the 3D Printer.

Mark 7 generator housing on a prosthetic limb. This will allow us to mount 2 motors to double our electrical output.

Alex setting up the charging circuit. We are getting a lot of use out of the oscope donated to us through the La Crosse Public Education Foundation last year.

Avery and Caitlin working on programming.

Avery and Alex working on soldering the rectifier circuit. It seem Avery is always eating???

Thomas working on the motor voltage simulation.

Work Night 1.10.19

Work Night

Date: 1.10.19
Location: Logan HS
Time: 4:30-7:30
Students: Paige, Alex, Thomas, Seth, Austin and Tanner.
Goal: Wire in the generation system to the buck boost system and rectifier to see what we get for electrical output.

This was a great work night! For the first time we were able to bench test our charging systems with only one motor/generator on the limb.

We need to get a new "Buck Boost" chip as the one we had a missing pin and we could not solder it in properly. We are checking the electrical schematic to see if the missing pin will matter. It could be just an input or output we do not need. A new chip has been ordered, but it is back ordered until the end of January. For testing purposes we are using a Buck Boost Board which is a larger version of the Buck Boost surface mount chip and is easier to mount and test for the students. When we create our final prototype, this board will not be used, just the chip.

Seth is updating the generator mount and has already printed another Heel Linkage Adapter for the heel that is curved to better fit the heel. We want to finish the new motor mount with the housing to protect the gears and then print it out to see how it specs out when mounted on the limb.

The software team has been making some strides moving from the hardware to the App we have created for phones. Still have some control issues and have to better define what we want the user to see and control on the phone. Austin is making an executive decision and moving to a different software to design the App.

We are still experimenting with turning motors into generators and changing the winding. Basically current increases with thicker wire and voltage increases with more turns in the winding. The limiting factor is the volume you have to places turns on the windings. As you increase the gauge of the winding wire, you can fit in more turns and you'll get more voltage but this comes at the cost of higher impedance and lower current capacity. A low gauge winding can support a higher current but at a lower voltage. This is really a balancing act.

Paige and Tanner worked on the Mid Term Grant Review presentation and time frame. Invitations will need to be sent out for this Feb 7th night.

This is a flow chart for our charging and energy management system.

This video shows a monumental step in our forward progress. It shows our conversion system (a Buck Boost board hooked up to a PS. If you look toward the bottom of the scope screen you will see a blue wave form suddenly spike up into the 5 volt range. This shows that it is taking a lower input voltage and through the use of inductors, increasing the voltage to a constant 5 V that we need to charge the battery. We later hooked this up to our energy storage system and within 5 steps on our tester we charged the capacitors to 50 V.

Alex soldering leads onto the pins of the Buck Boost board.

Tanner and Paige working on the MTGR presentation.

Seth working on the Mark 6 generator mount.

Alex monitoring an o-scope to see the output of the Buck Boost board.

Alex with the generation system hooked into the energy storage system (rectifier) and converter circuit.

Work Night 1.3.19

Work Night

Date: 1.3.19
Location: Logan HS
Time: 4:30-7:00 PM
Students: Thaying, Paige, Alex, Thomas, Tanner, Avery and Seth.
Goal: Solder the surface mount components for our Buck Boost charging system and work on improvements to the generator mount.

Great progress tonight! We started to solder the surface mount components in the charging system. This is not an easy process as surface mount soldering requires an entirely different level of concentration and attention to detail.

Everything was going well until we started to solder on the Buck Boost chip. It was soldered in with the orientation in such a way that only 7 of the 8 pins were touching. We need to get another chip ordered to try again. Unfortunately, that chip is on back order so we cannot complete the circuit until that comes in. We are going to try to heat up the leads on the old chip and move it back into position on the board. This could lead to some cross connection in the traces but we have to give it try.

The software side of things are looking more promising. The App creator and the Arduino are interfacing. We are using two different types of software to accomplish that which creates it own problems of its own. Austin changed some of the code on the Arduino and we lost some connectivity so he will have to trace that back. Caitlin is working on the App interface.

Caitlin also is ready to take the Sustainability test. To her credit this has taken a lot of time on her part to study and prepare for it. We have had a problem with tax exempt status from SolidWorks which creates a financial headache for us to get this cleared up.

Our fundraising window has started. We have posted information in the Alumni newsletter, on the school webpage and district Facebook page. We will continue to seek donations to cover the cost of travel and to purchase a CNC Router for the TE Dept.

Data from motor tests.

Alex soldering surface mount components for the charging system.

Thomas created the rectifier  circuit for testing. This will eventually be put on a circuit board.

Paige updating the engineering journal.

Thomas soldering surface mount components.

Seth working on a design for the generator mount to be 3D printed.

Tanner mounting the heel adapter linkage which was just 3D printed.

Sketch of new generator mount.

Sketch of heel adapter linkage

Soldering surface mount components.

Some additional thoughts on the generation system from our industry professionals:

1) current generator will provide only about 3% , so about every 5 cycles we may be able to operate electronics- very rough estimate, need to run experiments to refine!
2) Alternative generators in hand can easily double that capacity(samples 103 and 105 evaluated by students)
3) Looking at a modification to sample 103 to increase capacity to about 20% (rewind armature with 32 AWG wire in place of existing 36 AWG wire)

(The sample notation refers to testing Alex and Thomas did on sample generators. Each generator was labeled with a sample number.)

Have made a full capacity special design sample, but ran into some construction challenges-  may return to it later if I can resolve these.
Some online-available generators have adequate capacity but are discouraging in their large  size, and probably have large mechanical losses,.

If a bilateral generator system is used, we may be able to double capacity. Also, they could be wired in reverse generator polarities, so one generator would increase capacitor positive side voltage, while the parallel generator increases negative side voltage. this would aid total energy storage.