Week Seven - On To Testing!

Hey guys!  As far as I know, the car started driving after I left last night, which means that the next few weeks will be full of testing!  It also means this last week was crazy.

Tuesday was a little slow, since there weren't that many jobs that I was able to do.  For the first couple hours I was there, I made a bracket to hold one of the pedals in the car.  I started with a square steel pipe, which I cut with the horizontal bandsaw to the proper length.  Then, I coved out both ends, one with at 1" diameter hole saw, and the other 1.25".  After making sure it would fit snugly onto the chassis, I measured and drilled a .25" hole every .75", so the pedal could be moved if needed. Finally, I used the vertical bandsaw to cut it down the middle, so the pedal would fit between them.  After the parts were done, the team welded them onto the chassis.

For the rest of my time that day, I helped Alan make a plastic piece for his deliverable.  He had made designs already, so I merely assisted with the machining (on a lathe).

Thursday, I didn't have much to do, as I was there only 4 hours, and 1.5 hours of that was spent in the team meeting.  I did get to drill out some new tabs for the chassis, and I helped cut down and rivet together the splash guard for the rear of the car.  That's a couple pieces of steel that sit around the gas tank box and prevent any liquid from flowing into the engine or the driver.  It's slanted downward so anything that does spill or splash onto it will run off the back.  I've heard that in competition, the judges pour water over the back of the car to make sure the gas tank is airtight, and thus make sure the driver will be safe, so the team was trying to gain points in that section.

Saturday was the big final push.  Arms were getting welded together, panels were fitted perfectly, and all the little things were getting tidied up.  The main hold up for the car being drivable was the brakes system, which yesterday was focused on finishing.  New brake lines were installed, and the system was going to be bled after I left.  (Bleeding brakes is when all the air is removed from the lines, so the fluid moves around correctly).  I helped take the wheels off in the front to access the calipers.  Once the new lines were put on, the brakes still slipped a little, so I made four homemade washers to use as spacers.  The brakes lead, Stephen, picked out an appropriate thickness steel to compensate for the slipping.  Then, I cut out small squares and drilled a hole in each of them the same diameter of the bolt that needed to go through them.  To make them smaller, I used a grinder, until I had nearly-circular, MacGyver-style washers.

Anyway, that's all for this week, but I will definitely have pictures once it's running next week, and I don't have to spend every second there working.  Until then!

Week Six

Hey all!  So I called last week's blog "almost there," and that's still an appropriate title this week.  The car isn't driving yet, but it's darn close.  This week, I helped take the gear box out of Gold and put it into the new car. That may sound easy, but it took several hours.  Why?  We had to remove all of the wheel arms and suspension from both back wheels in order to remove the gear box.  After it was on the new car,we had to reattach everything, which is when we realized that the new car had the wrong wheel.  The back right wheel had no splines, meaning that the gear box shaft wouldn't fit.  Finally, the whole system had been installed, and the big push began.

Yesterday was all about divide and conquer.  We had some members working on paneling, some finishing the brakes, while others worked on the code for the E-CVT.  My job was classic engineering: take a problem, design a solution, and fabricate it.

The problem of the day was making an adjustable steering column to accommodate different drivers. We also wanted to gain points for the ergonomics section of the competition.  My design was great, I had a sketch and a crystal clear idea of the end result in my head.  The execution is where it fell apart a bit,which is why I have no pictures of the build (yet).  I overlooked the need to use a pilot drill when milling a pipe, that is to say, I went right to the drill bit I wanted without first starting the hole.  The pilot drill is designed to keep the hole in the center of the pipe, rather than slipping to one side.

When I was done, I had a pipe with holes perfectly spaced apart, but not even close to a straight line.

I also had a pin to design and make, to hold the steering wheel at whatever height is needed. I found a perfect piece of metal (after a disastrous attempt to make one in a lathe, leading to a bent cylinder twice the ideal diameter), and I drilled a hole into it to hold the pin onto the car.  My main mistake was trying to make a small plastic end to hold when moving the pin.  The piece came out nicely, but I had nothing to secure it onto the metal pin (I thought we had epoxy when I made it).  After realizing plastic wouldn't work, I tried to attach a small metal ring to the end, as I had seen on some other pins in the tool room.  Unfortunately, I couldn't manage to drill another hole in the pin.  I just have gotten lucky the first time, because the drill bit kept slipping, and the pin was far too small to use a pilot.

So what was the end result?  5+ hours later, I had a great design, and no usable parts.  But, silver lining, when I go in on Tuesday, I'm going to try again with the team member whose idea it was in the first place, and hopefully together we'll be more successful.

However, I got a taste of true engineering, from beginning to end, and I'm excited to give it another attempt!

Until next week!

Week Five - Almost There!

Hey guys!  This week was ASU's spring break, so I spent several more hours there than usual.  However, despite having more time there, I have less to talk about.  Mainly, I worked on making several repetitive parts, rather than a few different projects.  

One of the first big things I worked on was making another fire wall.  Unlike the build last week, I only had to trace the old one and cut it out.  Unfortunately, it didn't fit very well at first, so it took a couple hours to make it work.  The purpose of the second fire wall was to use during testing, without damaging the "good one."

I also helped with the side sail panels, which are triangular pieces on the back of the car.  They had already been designed and cut out of cardboard, so I traced them on the metal and cut them out with the shear, just like last week.  

The skid plate also needed to be attached.  That's a big, thick, plastic piece on the bottom of the car that protects the driver from any mud, dirt, rocks, etc.  We didn't have a big enough plastic sheet yet, since the plate is probably the largest single part of the car, at over 5 feet long.  Instead, we took the skid plate off of Gold to use on the new car in the meantime.  

All the panels are held on by rivets drilled into tabs that are welded onto the chassis.  The skid plate required 13 (?) of these to be secured completely.  When the tabs are cut out of the metal, they are done using a water jet, which rusts them.  So as to allow for strong welds, the rust had to be removed using a sandblaster, which was another of my projects this week.  After de-rusting all of the necessary tabs, one of the college students was able to weld them onto the frame.

The last main job I had was the most time consuming, and mainly the one I'm referring to above when I say "repetitive."  Yesterday, the interns were tasked with making more plastic inserts for the wheel arm mounts.  Basically, there are metal rings welded to the front of the car, on each side.  They each have a plastic smaller ring fitted into them, through which is put a bolt that hold the wheel arms in place.  We needed to make more plastic pieces because whoever welded the metal rings didn't take the plastic out, so it melted and deformed.  

To make them, we used a lathe, and pretty much every type of tool.  We first faced the sides and the front of the cylinder to two segments of different diameters.  Then, we removed material from the front until the piece was the right length.  Then, we drilled a hole through the entire material.  Next, we chambfered the front, which is making a small cut on the edge to remove any small lip that would prevent the part from fitting onto the car.  We then used a parting tool to cut the piece off, and finally faced the back side of the part down to the proper length.  It took us 5 hours to make 4 of those parts, so that was most of the day.

This Wednesday is the (optimistic) deadline for finishing the car, so it can be tested.  Looking at it now leads me to two predictions.  Either:

(1) Everyone steps up and works harder than ever, and the car does indeed get finished in time.

Or, more realistically:

(2) The car doesn't get finished, and the team receives a stern lecture from the leads, which is what happened when the cost reports were due last month. 

Either way, this week is likely going to be my busiest yet, and I look forward to sharing the experience with you.

Cheers!

Week Four - the Fire Wall!

Hey guys!  So this week was a bit busier than weeks previous.  We're getting close to when the car needs to be complete, and there's a lot of work left to be done.  Rather than summarize what I did this week, like I've done in past blogs, I'm going to show what I did yesterday, step by step, from the time I got there to the time I left.

The goal: to design and create a fire wall.  Simply put, the fire wall is a sheet of metal behind the seat that protects the driver from both the heat of the engine, and (worst case scenario) any catastrophic malfunction.  This picture is of the fire wall on last year's car, nicknamed "Gold."  It's the large black piece with the ASU decals.

Step one: We measured the back of the car, where the fire wall was going to go.  We sketched it out on paper first to record the dimensions.  Unfortunately, it slipped my mind to take pictures of my sketches.

Step two: We began measuring and drawing out our sketch on a large piece of cardboard.  As opposed to last year, the team wanted a two-part fire wall, with some overlap, so we cut out upper and lower sections.

Step three: After making sure the cardboard pieces fit in the car correctly, we were ready to transfer the design to the actual metal.  We used a 12ft X 4ft piece of sheet aluminum.  In this picture, it's covered in protective plastic.  The blue circles indicate where the metal was creased and/or dented, so we avoided those areas as much as possible.



The actual metal looks like this:

Step Four: we cut out a large rectangle that was 34" X 48" so we didn't have to move around the entire 12' sheet every time we made a cut.  To make this and all subsequent cuts, we used the shear.  I would've had a video of it cutting, but I wasn't able to get a good angle that actually showed anything happening.  Here is a picture of the machine:

Step Five: After cutting the sheet down to a workable size, we traced out the cardboard pieces onto the metal.  We gave them an extra 1/2" on one side, and an extra 3/4" on the other, because the cardboard was slightly too small on the car.  Then, we put them in the shear and cut them out.  When all the big cuts were done, and the plastic was removed, we ended up with this:

Step Six: Note the small blue marks on the metal.  These indicate where parts of the chassis were, and where we needed to remove some material in order to make the wall fit, not unlike the grooves in a puzzle piece.  Robert was in charge of rounding out these areas, as the shear can only cut straight lines.  He used a Dremel tool, and made curves for all the paneling that the other members were making as well.

Step Seven: After every small cut, we took the piece back to test-fit it in the car.  The last thing we wanted was to cut too much and have to redo the entire wall.  Here is a picture of the bottom section, once we got it to fit properly:

The top section was much bigger, and it had four curved areas, rather than just two (like the bottom), so it took much longer to cut perfectly.  After all the back-and-forth between the car and the Dremel, we had almost finished...

Then the tool broke.

The tool should be a circle, not the weird, fan-shaped fragment that you see here.  Fortunately, the heads break often, so they're sold in packs of 20.  Unfortunately, that wasn't the first one we'd broken, but it was the last replacement one we had.  That put a halt to the entire fire wall build, but once we get more, we'll be able to finish it, along with the rest of the paneling.  

And there you have it!  I was from ASU at 9:45 to 4:45 yesterday.  I started the fire wall 10 am, and the last Dremel head broke at 4:44.  I hope to share more all-day projects with you, as I enjoy having a big task to start and see through all the way to completion.

Until next week!