Sunday, April 9, 2017

Week Nine - It's Over

Hey guys!  I just finished my last week with Baja!  I hit 150 hours exactly, just in time for a whirlwind next few weeks that would make working at ASU very difficult.  It was a pretty slow week, so I've got some interesting things that happened during the week, but mostly some lame at humorous descriptions.  That being said, let's dive in...

TUESDAY

For the first half hour or so, I took advantage of the machines at ASU to make some parts for my deliverable that I wouldn't have otherwise been able to make.  I'm going to put up a separate blog for that project.

The rest of the day was kind of slow, since we once again had several things to do, that were all beyond the ability of high school students.  We did spend a lot of time working on the front brakes, which meant removing the calipers yet again so the lines could be changed out.  After I took off one of the wheels and calipers, I watched the rest of the process, in between retrieving various wrenches, zipties, and bolts.  When I left, the couple of team members left were about to start bleeding the brakes again, which can take over an hour.  Slow work, and honestly one of the only relatively boring things I've done there.

THURSDAY

Thursday was perhaps even slower than Tuesday.  When I got there, only one guy was there from the team.  A couple other interns were there too, but no one had anything to do. I even checked the "to-do" list on the Google drive for the club, but there was nothing on it that I had either the ability or the resources to do myself.  It was about 15 minutes of sitting there waiting, then Professor Contes walked in to check on the team.  When we saw us, I told him about the to-do list, and he agreed that we couldn't do anything from it at the time.  After noticing that no one else was in, he invited us to audit one of his classes for the next hour.  I was the first one to accept, and the only one to do so without hesitating :)

The class is normally about the chassis of the car.  However, the students had moved onto their final projects, so instead, Prof. Contes gave a presentation about the General Motors Proving Grounds that used to be locate just across the street from the Polytechnic campus until a few years ago, and where Prof. used to work.  It was great timing, because as enthusiastic as I would have been to audit a chassis class, it would have all gone over my head, especially this late into the curriculum.  Everything worked out perfectly that he discussed something that could be understood by someone like me.  He gave a detailed account of all the facilities, buildings, functions, and research programs housed at the site, and even why it had been located there (hot, dry, and mountainous: good for pushing new cars to their limits).

After the class, I watched Jesh (electronics lead) work on the E-CVT for a little while, until he and the other leads left for the weekly lead meeting.  That left only four team members and a couple interns with nothing else to do for an hour before the general meeting.  We ended up playing frisbee golf outside to pass the time (Coleman brought it in a few weeks ago, no one knew why).

At 6pm, we all went to the meeting, which was an hour-long reprise of stressing the importance of finishing the car on time, as well as some discussion of travel details for the first competition, which is in less than three weeks.  The rest would take me too long to explain the surrounding details that make it understandable to anyone who hadn't been intimately acquainted with the team for the last two months.  Anyway, thus ended my least productive day at Baja.

SATURDAY

Saturday was my last day.  It was the most productive day this week, but not as efficient as it needed to be.  With the competition in just two and a half weeks, there was (and still is) so much that needs to get done on the car.  We started the morning with a checklist on the whiteboard of all the things that needed to be finished before the car could drive that day:
I know it's hard to read, but it was hard enough in person, so it's best picture I could get.  The only important thing in the photo is in the top right corner.  It says, "1pm: Car Moving."  When I left at 3;30 pm, the car was still not moving.  We got sort of behind schedule, but we did get a lot of the list items completed.  I personally finished two of them, entirely by myself, which I'm proud of :)

1) I secured the gas tank box onto the car.  On the Baja cars, the gas tank itself is protected by a metal box, which is required to latch, and prevent the tank from moving around during driving.  Here's a picture of the top half of the box.  The rest is under the splash guard (the big metal sheets around the box).


Securing the box meant drilling holes into the bottom of the box to match the holes in the bracket that had already been welded to the car.  It didn't work out as simply as that, however.  The gas tank was old, so the holes that were already in it matched the bracket on a different car, which were close to the new car's, but not close enough. Three of the four holes matched up partially, but no two matched up perfectly.  So, when I drilled through them, I ended up with three holes that looked like a cell in the end stages of cytokinesis (hey, guys, I remembered something from biology!).  Anyway, fortunately, the widened holes were small enough for the heads of the bolts to still secure the box, but I wasn't sure if it would work until all of the bolts were in place and tightened up.  It's hard to see the messed up holes with the bolts already in place, but the most pronounced ones are the two on the right.  Look above each bolt and a little to the right.  The tank is partially in the picture as the black plastic thing on the right, with the fuel lines coming out of it.


That concluded the first (and easier) project that I single-handedly crossed off the list.

2) I made gussets for the rear shock arms.  (I purposely worded that in as complex of terms as possible, just to show off the fact that I've learned a lot these last nine weeks).  So now let me explain what I just said in layman's terms:

This is a rear shock arm, a triangular-ish tower that welds onto the chassis, and through which the shock bolts into place.

Notice how the bracket on the top of the tower leaves a large gap above the shock, at least an inch and a half.  The front towers have brackets that extend right up to the top of the shock, leaving just enough room for the shock to move during a drive.  My job was to make gussets, or small pieces of sheet metal that filled in those gaps (not the two triangular gaps; those are supposed to be there).

Doesn't sound like much work, right?  WRONG!! These two pieces of steel took me probably two hours to make.

I started out with a large sheet of rusty steel from which had been cut out several different parts for the car.  I was allowed to make the gussets out of a medium-sized strip on the edge, so as not to ruin the stencil-like shapes of the other parts.  I decided to cut out a 1.5" X 1.5" square for each gusset, giving me plenty of room to cut it down and make the curve for the top.  That alone took maybe a half hour.  I had to use a Dremel, which is time-consuming enough of a tool for thin metal.  I never measured the thickness of the steel in question, but I'm certain it was at least 5 times as thick as the metal I cut before for the paneling.  Once I had my two squares, I sandblasted them to take off the rust, to make it possible to weld them onto the towers when it came time.  Then, the real challenge began.

I had to start shaving them down and making them the correct size.  I first placed the squares over the shock towers and drew lines on the left and right edges where they met the tower bracket, so my gussets would be the right width.  I used the Dremel to achieve that.  Next, I had to make them the right height, and cut the curve that would help them fit into the tower like puzzle pieces.  I tried using the Dremel for that too - for about a minute.  I knew it would never work, the metal was just too thick, and I wanted a nice, smooth curve.  I decided to try my luck on the table grinder, which I used a few weeks ago to make the caliper spacers.  The grinder looks like this, by the way:

  
I used the orange wheel on the right.  I had to turn the machine up to almost maximum speed (which is 10000 RPM) to get it to take off any of the steel.  When it did cut, it looked like one of those little firework fountains on New Year's Eve: a constant stream of bright sparks that came flying out, and right at my hands and arms.  Interestingly, it's pretty painful to have hot steel dust spraying at you, but it doesn't leave any sort of scarring.  But I'll divert away from the morbid stuff.

I kept having to re-position the gussets in the pliers I was using to hold them on the grinder, because the force of the grinder kept pushing them around.  I won't lie, it was really hard to grip the pliers hard enough to keep the gussets still.  And I couldn't just pick it up and put it back in the pliers, because the whole point of using the pliers in the first place was to avoid touching the metal.  Grinding off steel heats up the metal immensely, so every time I wanted to test fit the pieces on the car, I had to walk all the way down the hall to the bathroom to run cold water over them, so I could even touch them.

After over an hour of grinding the curves and Dremeling the straight edges when they were the wrong size, I had finally produced two gussets that were small enough to fit on the tower, but large enough to be welded on without gaps:

They didn't get welded on before I left, so I can't show you all what they looked like, but I hope this gives you a good enough idea.

I did a ridiculous amount of Dremeling, and that can eventually wear down the cutting wheel.  I started with a mostly-used wheel, which I proceeded to completely use up, as well as a new one, and a little bit of a third one.  Here I placed the second completely used wheel next to a fresh, unused one.  Just though that was kind of funny, and it's a perfect way to illustrate just how much cutting I did in one day.


I was sad to see that the car wasn't driving by the time I left on Saturday, but I'm very glad I got to see it once before I stopped going in.  I wish the team all the best for competition, and I look forward to hearing how well the car does at the end of the month.  Since I finished my internship in 9 weeks, rather than the 10 that most people will do, I'm going to put up at least one more weekly blog, to stay fair to everyone else.  I'm going to walk through the process of making my deliverable, a fully-functioning music stand!!

Until next time.  Cheers!  













Sunday, April 2, 2017

Week Eight - Finally?

Hey guys!  The car finally started moving this week, but there's still a LONG way to go for competition.  Given that the first competition is at the end of April, I'm really thinking it won't be ready in time.  That being said, here's what did get done this week:


TUESDAY


So I'm trying out a new format; bear with me.

The lead engineer was sick on Tuesday, and not many guys showed up, which both led to a relatively slow work day.  The lead (Coleman) messaged me in the group chat we use and tasked me with making new bushings for the brake pedals.  They're small plastic cylinders that sit between the brake pedal brackets and the pedal itself, to avoid the pedal slipping around.  I started out by taking measurements, and I made a rudimentary sketch in my notebook so I'd know how much to cut the plastic.  I won't ruin this blog with my awful art skills, but the sketch did serve its purpose.

I took my sketch and long plastic dowel to the band saw lab to cut the rod down to a size that would fit in a lathe.  When I got there, I noticed that the saw had been taken apart, and the blade removed.  I'm guessing it was to replace the blade, since I'd heard several different people complaining about missing teeth and dullness, but whatever the cause, it meant I couldn't cut with it. Luckily, I found a hacksaw back in the shop, and (twice) luckily, I was cutting plastic, not metal.  If I'd needed to cut an aluminum or steel rod, I would've just had to wait until the saw was fixed (side note: it finally was on Saturday).

After I had an appropriate-length piece, it was just a matter of lathing it down to the other proper dimensions.  The process was a bit tedious, but using machines hasn't yet gotten old (I doubt it will for me).  As interesting as using the lathe was, I don't think I  can manage to describe it in a way that isn't 100% boring, so I'm going to skip ahead to the finished product.

My original bushings were almost twice as big as they needed to be.  The reason was that placing calipers in between the brackets was near impossible, so I didn't measure and accurate length.  There was also a plastic piece attached to the pedal on each side, which I thought at first could be removed, but when I realized it was there to stay, I had to cut the bushings down much further to fit.

Once I realized they needed to be smaller, I was still in the frustrating situation of being unable to measure the necessary size correctly, so the next half hour or so saw me going back and forth from the machine lab to the shop to test-fit them on the car, and then cut some more.  At last, they fit beautifully.

The original (too long) bushings looked like this:


They fit into the brackets like this:


{I couldn't get a picture of them on the pedal, because when the pedal was between them, they were impossible to see.}


THURSDAY


Thursday was the least-eventful day.  It usually is, since I'm only there for 4 hours, and the weekly meetings take up at least one.

To start the day, I helped attach a box to the back of the brake light to hold it in place on the splash guard.  That meant first removing the old rivets from the box (just a small, X-shaped piece of sheet aluminum).  Next, I held it in place over the light and drilled through the pre-existing holes in the box into the back of the splash guard.  Then, I finished the installation with fresh rivets to secure the box (and thus the light).

The rest of the day was mostly watching stuff get done, until about 5:30, when the project leads left the shop for the lead meeting (which always happens before the full group meeting at 6).  Coleman told the 4 of us interns and 2 other members left in the shop to clean up until 6.  After putting a few things away each, everyone else stopped working and just sat around.  One of the other interns was working on his deliverable, so I'm not counting him, and one of the others helped me a bit, but I did 90% of the cleaning.  I'm the only one who even picked up a broom.  At 6, they all left for the meeting, and I kept cleaning for at least 10 more minutes, until the entire lab was tidied up.  After that, I went to the meeting with everyone else.  I admit I was pretty frustrated at the general laziness of the other guys, but I also didn't make a big deal out of it to them, so I'm partially responsible for the fact that no one helped me.  But I digress...

SATURDAY

Saturday is when the car finally drove!  I guess they had driven it a little on Monday, but Saturday was the first day I saw it.  Before it was ready, though, we had to replace the oil in the engine and the gear box.  That was a pretty self-explanatory process, but it was somewhat time consuming, because the entire CVT had to be removed to access the plug in the gear box, and the engine kept dripping for several minutes.  Eventually, the necessary amount of new oil was measured out and inserted into the engine/gear box.  Once the CVT was put back on, one of the guys on the team gave me another big open-ended solo project (my favorite!!) which I will try to best explain with images.

THE PROBLEM:

The seat belts attach to the chassis through two large rectangular holes in the firewall, which leaves two large rectangular spaces for heat/fire to reach the driver.  I had to design and manufacture a box to enclose the seat belts, shielding both them and the driver from any harm.  Here's a picture of the exposed seat belts on the car:


I started out by taking measurements of the opening, and sketching basically a standard prism with those measurements.  I had to modify the front face, since it needed to be open and have circular holes carved out to fit around the seat belt and the pipe of the chassis.  It also needed to rivet onto the firewall, so I had to design tabs on it as well.

My design boiled down to two pieces, riveted together into a box.  The first piece was a rectangle with half-inch squares cut out at the corners, and the edges folded up to form a half-inch lip around the perimeter.  I made this piece correctly on the first try.

The second part formed all four of the walls, and the open front face.  It took me three attempts to get it right:

1) When making my designs, I overlooked the fact that the box was not square, so my wall piece had all the wrong sides for the back piece.

2) I corrected my designs and cut a new piece with the right dimensions.  I cut and bent the metal into the square I needed, but I forgot to cut the circular pieces first.  Since I had already bent it, using any machine or tool to cut the holes would've been much more trouble than it was worth.  If that had been the only issue, however, I could have found a way to do it.  That being said, there were a couple other problems that warranted making a new part just for simplicity's sake.  The first was that I had neglected to make an overlap on the wall part, which would've left a large gap on one edge of the box.  It's possible it wouldn't have been noticeable once the box was completely assembled and riveted onto the car, but I didn't want to take the risk.  The second issue was that I had bent all the tabs inward, which I realized would put them inside the hole I was working to cover.  Again, it's possible I could have bent them back, 180 degrees, but that might have weakened the metal, another risk I didn't want to take. Long story short, I scrapped the second attempt and hoped that the third time would be "the charm."

3) I adjusted the dimensions to accommodate a half-inch overlap on the wall piece for a rivet to hold it together.  I also made sure to cut the circular holes first, and test-fit them before bending the metal.  I ended up needing to make them larger later anyway, but it was easier than it would've been to start them.  I also bent the tabs outward, so they would attach to the car correctly.

Finally, when I had two pieces that fit together and fit onto the car, I riveted the whole box together, and I'm proud of the end result:


During the several hours it took to make that, one of the other members helped me learn how to use the mechanical punch and the sheet metal bender.  He also decided to work on an alternative design based on last year's boxes, since we did need two anyway.  The old box was a much  more complex shape, more trapezoidal than rectangular, because the previous car (Gold) had different drip pans, so the box had to fit around them.  My guess is that the team will end up using his design, since it probably looks better (although no one will see them anyway), and it was crafted a bit more expertly, but I'm no less proud of mine.  After all, he (albeit incredibly well) copied a pre-existing box.  I took measurements of the car to design and create my own from scratch, so at the end of the day, which one is better?  His, definitely his, but he's in his second or third year of college engineering classes :)

The box build took me until about 3:00 (I got there at 10)  A little while later, the car was ready for testing!!  I'm going to explain a little of what exactly we were testing, but most of the rest of this blog is going to be pictures and videos of the car driving around.  Why?  Because it's actually running!!

First time starting the car that day:

Driving around:


 Checking the brake pressure:


 More driving around:


Testing out the car's maneuverability over relatively small gravel/dirt:




So, the main thing we were testing was the brakes.  Coleman was driving, and his goal was to get it up to top speed (around 30-35 mph) and slam on the brakes to put maximum force on the system.  As you can see in this video, it doesn't stop immediately, because the wheels don't lock up completely.  That was a big problem.


 After a few minutes of mixed success (depending on the terrain: dirt, grass, gravel, pavement, etc), we took the car back inside and adjusted the brake pads.  That meant taking off the entire wheel to get to them:

The best close-up I could get was this one.  The brake pads are the black plastic pieces in the middle.  When the driver pushes the brake pedal, the pressure pushes the brake pads together, and they (are supposed to) grab the wheel rotor to stop it from turning.  That wasn't happening during the drive.


 We also put on new rotors to see if the pads would grab them better.  The rotor is the dark metal circle on the inside of the wheel, with the funky pattern of holes and slots:


After maybe 45 minutes or so, we took the car back out, with new rotors and cleaned brake pads, to see if they would make a difference.


I decided to get a little artistic with the angles :)



The car seemed to be braking less evenly this go-round.  I mean that the left wheel was now locking up almost perfectly, but the right one wasn't at all.  Basically, one side got better, and the other got worse.  It successfully braked with both wheels on grass, but on the dirt, gravel, and pavement, it proved unsuccessful.  I took a couple more videos of the car driving, but I unfortunately put my iPad away before it braked on grass.  I had already written it off as a universal problem, so I missed the opportunity to put it in the blog.


Well, that does it for this week!  Due to my crazy April schedule, I've put myself a whole week ahead on hours, so I'm heading into my final week.  I won't have much chance to go in after that, so here's hoping for an eventful and productive last few hours, and I'll check in with you guys when I hit the big 150!

Cheers!