Wrapping Up the Semester

I apologize for not realizing that the blog was not updated as it should. There were some silly technical difficulties I didn't realize and will now add my last 4 posts in one large post...Thanks.

The weeks before Thanksgiving break.

Tasks:

- Become more knowledgeable with G-Code

- Machine Plastic Samples

- Prototype?

My goals here are simple. I have built enough of a foundation to start some of the visual prototyping of my design. I was able to work with a TA in the AFL lab and machine five different blocks that could work as a final product. My design was well thought out in CAD however, in real life, we all know that what looks good on paper doesn't necessarily mean it'll work in real life. So, I tried several different manipulations, machining stages, and came up with a couple blocks that do exactly what the police officer required.

Unfortunately during this time, I became quite sick and missed two of the lab meetings. I had an ear and throat infection that eventually led to nearly a week of doctor prescribed rest and quarantine from campus. My doctor said she had to be aggressive due to the campus wide out breaks of H1N1. After two weeks of antibiotics I finally began to feel better right around Thanksgiving.

Following Week:

Over the last weekend of break, I was finally able to create my best working design that limited the amount of cuts, drilling, and designed-mutilation of the UMDH. Hopefully I will be able to corporate this sample and the air sampler in the design review next week.

A group matter:

I was able to review my comments of what was said about me from my group and the grades given to me by the T.A. and I feel that an explanation could do some good. My communication with my group and attendance wasn't where it should have been to be considered a member of the group. I was a section leader in the marching band, and when group meetings are during normal hours, I'm at rehearsal, and when they are on the weekends, I'm either performing at a concert, or marching at a game. It was very difficult to be able to find times in which all team members could meet. I didn't even get to meet the one of the group members, yet she seemed to be approved to work in the lab! It seemed necessary for me to not be involved with the group testing chemicals in the lab, and that an individual endeavor would be more productive to the final outcome of the MSDA group. That's why I work on the air-sampler. As a result the group members never really got to meet who I really was and how I like to do things, this is definitely something that can/will change next semester.

Design Review:

Preparing for the design review was a little bit of a chore for me. I was able to meet with the group after they tested the sampler at the Prof's garage and a lot of good was done there. Unfortunately for me, it seemed as if the sampler design that existed was good and all fine and dandy, but wasn't really designed with the user in mind. We discussed that a proof of concept pump worked, and that the SLA created sampler should be reconfigured. It seems as if all my work trying to adapt the existing device might have been "wasted." Perhaps guidance isn't the best thing in the world, and that knowing when something is wrong, it takes going down the path to the end to realize that, yes, we should have turned around earlier because this wont work.

After a night of discussion, a proposal was made that the original CAD file of the design should be examined and altered. Bigger, and more ergonomically designed for the user, yet still able to fit on a belt for the officer. This will allow a higher rate of ease of use, and help the noise problem because of the added size to allow for a dampening solution, rubber pellets or something. This design will also incorporate a hex-head, screw valve for a direct connection to the Sorbent tube. (What I was trying to solve with the UMDH, eventually the final product will be machined out of the UMDH.) A little disappointing to come this far and turn around, however, it's what we should do.

After the review:

The biggest thing I learned all semester, and that was brought up by an engineer during the review, was that everything we do as engineers needs to have a reason and a place to start. Each process should be started all with the project partner in mind and that the design should evolve from specifications. Which is a damn good reason to take the sampler back to the drawing board and create a new one that works to what we need it to do. Many of the same technologies will be used, ie the pump, battery, circuitry, etc. however, the housing needs extreme modifications.

Prototpying - Phase 1

Last week I was able to work with a TA from the AFL machining lab and got a lot of suggestions and improvements to my simple design. He recommended some different choices as far as the machining process goes and how I can utilize varies machines for more accuracy and a greater chance of success.

I started working with him on a CNC milling machine learning the basics of G-code. I've work very little with such advanced machinery, however, I feel like if I had an X and Y and Z axis knob I would do just fine. I created a program that does what I need it too.

Some problems that first started out were the machining speeds, I had some ideas from working with this type of plastic before, however, you never really know until you cut some passes and hold the objects in your hand if you're cutting too slow or two fast. I was able to solve this problem relatively quickly by trial and error and examining the cuts.

After my last exam tonight, I should be able to move this phase of the process to the top of my priority list and start making some pieces for the air sampler.

The TA also thinks he might have a solution to the valve idea that I had. It will be similar to the latch theory that was brought up during the lab meeting.

Machining

Today I got another certification and clearance in a better machining lab on campus. I'm not allowed to use every machine all willy-nilly, however, I have access to high quality and newer machines.

I'm working with one of the TA's on duty at the AFL to work my design, and machining process. Hopefully with his help this will move along quite quickly. Once again, I'm rather excited to get my hands dirty.

Another design option crossed my path today, what if a latch valve existed? Something like the latch on a metal linked watch band, or something like a hose clamp. This would allow a quick connection and an ability to be heated.

Either way, the valves will be ordered this week, and progress will be picking up. My goal is to have a working representation of my product for the project partner to see. This by no means will be a perfect final draft, as I hope that would have steal tubing, permanent connections, and a means to take multiple samples at once.

Major Update

After my last post, I became a bit sick and left early for fall break. However, when I was well enough to work on things I did.

My major break through's include

1.) Plastic Supplier /Distributer

2.) CAD design

3.) Machining Practice

4.) Design Review

5.) Valve Selection

1.) I was able to contact four different suppliers over fall break. I described what I was doing, and for who, and asked for their suggestions. I explained that I was more of an amateur machinist, but learn quick, and enjoy working with machines like lathes and CNC devices. I was referred to the company CDS Plastics, in which I was able to get donated four bricks of UMDH, High Density Polyethylene.

It's not super easy to machine, but with sharp tools, a good plan, and adjustable speed settings I should be able to manage just fine. The plastic is incredibly durable, it's the toughest stuff around. Luckily for us it's relatively cheap, and in this case, I was able to get it all donated.

I received a 27 pound package in the mail last week, and plan on machining in the near future.

This is big for our group because, with out the Mass Spec working, we can't begin testing and we don't have any tangible progress, so having a piece of plastic machine will look really good on our overall progress.

2.) I put together a projection rotation sketch in Auto CAD. Just something to show people my mind's eye. It's simple, east to make on either the SLA or to machine. At this point I'd like to machine it because 1. I'll learn more 2. It's more fun for me 3. I don't have enough knowledge with the SLA yet.

I will be using a radial arm saw. Drill press. Router. I doubt I'll need anything else. By creating jig and fixtures I'll be able to adjust and recreate my pieces while building, rather than creating something on screen, telling a CNC to do the work, and making a mistake that I can't foresee until the final product.

Extra materials I'll need are:

1 - rubber o-rings

2 - machining screws

3 - 12 inches of 1/4inch OD tubing

4 - valve

5 - I'm sure I'm over looking something.

3.) I've submitted my "application" to work in the ME lab to build these pieces, however, have not been given "clearance" yet to get my training. At home I have all the tools and bit I'll need to create the pieces.

4.) Valve selection. I need to see a sorbent tube and have not been in the lab to take exact measurements yet. I also don't know what the advisor needs and how my team plans on using the tube in conjunction with the mass spec. This information will help me on selecting a cheap valve made of plastic, or an expensive one made form stainless. Each valve will work.

5.) Our team had the design review last week. I think because we're all a little inexperienced with MSDA, and aren't superb with communicating what happens at meetings and out of our meetings that is why we didn't perform so well. During my portion of the presentation. I should have known more about the Tenax, however, I really do not give a woof about the chemical workings. As long as the sorbent tube does what it is supposed too, then good, I don't need to know the carbon to carbon bond structure inside...What I was concerned with was making a good transition between my mind and the client's, to a group of respected engineers. I made some good analogies showing my knowledge about the subject and that I have a clear understanding of what needs to be done and the problem at hand. I presented my solution and how I plan to achieve it. I was congratulated afterward. I'm rather proud of my performance.

MSDA Meeting

Today we talked with our advisor about the chemical testing process. Overall it was a productive meeting, however, there were some discussion topics that weren't exactly discrepancy free.

We need to do a dummy test in which we can prove our concept. We have a controlled environment that is injected with a ppm of something household, like methyl silicate, winter green, and then see if the sampler can collect and the spew the particulate back into the Mass Spec. We will also try with various forms of ether, so forms of alcohols.

To start this process we need to know the lower bound of the Mass Spec and what molecular masses will work well with CIT Ion collector. We think this value should be about 50 grams, but we're not sure yet.

Our advisor has sent out the goal for us to successfully test this device, and then eventually figure out a standard equation of sorts, to find the ratio of chemical in ppm to the number of m/z when collected with in the machine. This is some sort of ionization constant that we know exists, however, might be impossible for us to calculate at this time. It will be beneficial for us to understand that LOD curve.

At this point I'm very much out of the loop with the actual testing, but my group is solely dependent on me to produce a higher efficiency design with the air sampler and to make it indestructible as well as easier to be tested with.

Success

Over the last week I accomplished all the necessary tasks to be able to do research in the MSEE lab.

- Trained / Signed Forms

In addition to that I also stayed after the necessary training to learn about the SLA machine, how it works, and how I can utilize it for future tasks of adding more to the design of the Air Sampler.

I'm actually excited about working with the machine, it's quite different than what I'm used to.

Semester Planning Meeting

I was very pleased this morning to find that our advisor was pleased with our progress, and moreover, our openness and willingness to design and think through what needs to happen. At this time I won't comment much about our semester plan however, more about the progress of what I did this weekend.

I had the air sampler in my hands this past week quite a bit and have come up with a cost effective design that potential will solve to issues. 1 - needs to meet the project partners descriptions of size and durability, and 2 - needs to increase the efficiency of the device. I will not be redesigning the whole sampler from scratch however, will be adding to the device. What i would like to do is machine a piece of nylon that clamps over the base of the device that channels the suction through a plastic tube that mounts a sorbent tube to a quick release gas fitting from the previous link.

In today's discussion with the advisor, everything seems as if I can dabble with the ideas, but not yet create the product. I totally agree, it is good to look ahead, but why fix it if it isn't broke? Essentially, I can improve it and at some point I will. There are higher priorities at this time.

My machining skills and previous work experience should come in handy.

Research

http://www.mcmaster.com/#quick-release-tube-fittings/=3jk9x5

This website will very beneficial for me to use the air sampler design to the fullest capacity.

Air Sampler and PP Meeting

The MSDA group met last week to discuss our semester goals and how we would divide and conquer these tasks.

I was appointed, and requested, the job of redefining the existing air sampler. What this means is that I will recreate the device using the existing concept, but make it more 'police-friendly.' Our Project Partner decided that this device needed to be more rugged, smaller, and less loud/annoying to operate.

What I plan on doing, now that I have the device in my posession, is to take many measurements, observations and photos to create an image in some form of CAD software. This way I can play with my design with out altering the current progress from last semester.

My main goal is to have with in a couple weeks, a working design to the clients specifications, but also to improve on what I currently have. I propose to do this is that I will do away with the plastic casing and create one from machined metal, hopefully to be designed and donated by CDS machining, and to have all connections on the device to be threaded, rather than a pressure fit. This should allow for a very simple and quick design for testing with the mass spectrometer and also with the durability of the product. The sorbent tubes will hopefully fit into a brass housing that I can find at ACE Hardware for a relatively cheap cost. I'm looking into brass gas fittings as well as AC unit fittings. Each are cheap and easy to come about.

This week in MSDA

There was a meeting held on Sunday afternoon, however, I was out of town and unable to attend. The team elected two Co-Leader's to help fill in the gaps when our go to person isn't able to be there. We selected a time of Wednesday's at 6PM to meet and work on our projects. I have student leadership meetings with AAMB at that time so I will most likely be running late to most meetings.

In lab this morning we discussed what each group was working on, and established some goals for us with help from our advisor.

Next week we have our first meetings with our project partner.

Our goal as MSDA is to continue expanding our current chemical library, create a portable device and test it by semester end, and continue to contribute to the advancement that our project partner advises.

I don't think at this point there are any questions from the TA to answer like there was last week. However, I will be on here frequently updating what I have been observing and learning.

Thanks.

Reflection Questions - Week One

TUESDAY, AUGUST 25, 2009

Reflection Questions - Week One

1.) With minimal instructions and a time crunch, the project partner needs to be involved from step one. By having the design team ask questions to best design a product for the user, is a very critical process. With out the project partner, the design could vere away from what truley needs to be done, and then a faulty product would be designed, time would be wasted, and in this case, children would stay ill.

2.) Ask questions. Present groundbreaking updates. Continually check up on partner status. (Does the design still need to be made?) Budget.

3.) Statistical background information. Client input. Previous solution methods that didn't work for their problems.

4.) Have any fatal interactions occured when the police force inhabit/take over a meth facility? What was used in place of our product before we started working on this? Is the intention that any police officer, with little to no education in technical matters can operate such a device, at the job site?

1. a) I can see myself being a team leader and a project liason. Mostly because of my previous communication and leadership training from scouts, band, and work experiences.

b.) I don't know them well enough to determine what their strong and week points were.

c.) I could see how the CFO would be a nusance, however, a budget is necessary.

d.) All roles are needed, however, many of their tasks can feel over whelming, with a group of this size, it would be nice to see more of the tasks delegated to more people.

2. a.) Communication should be the most imporatant thing. Be respectful and courteous when talking to others, we're all at Purdue, none of us are "stupid." Emails, phone numbers, and facebook names should all be shared and regularly used to plan for meetings and work sessions. Be on time. I can't stand people who say they have integrity, clearly have brains, and show up late or not at all to group meetings.

b.) A well meshed group that had similar goals, if not the same, that was able to work effectively and efficiently together to reach those common goals.

c.) I'm not a fan of students grading students, however, a teacher/advisor review should be necessary if certain team members cannot follow up with their duties.