Week 3 "test boards complete and testing a sensor"

During this last week of class we finished up the last of our relay test boards and were each given a sensor out of a box and asked to find out what kind of sensor it was and test it if possible.This was the sensor I was given. As soon as I was given this sensor I was pretty sure I new what it was. I thought it was a wheel speed sensor and it was.

After looking up the number on the sensor I learned that it was on fact a wheel speed sensor. This is a Wabco S+ sensor for a Benz Truck specifically a wheel speed sensor for the ABS system.








The next thing was to figure out how to test this sensor. I really had no clue where to start, so I got on you tube and was able to find out how to test wheel speed sensors either on the vehicle or off. Below is the a link to the video that helped me understand what I was doing.
 .https://www.youtube.com/watch?feature=player_detailpage&v=7eCJa7JZzfg

Here is is a picture of me testing the sensor for resistance, now as far as I could tell from my testing, the sensor I was given was open some where. It was a bad sensor. I was unable to find what the resistance that this particular sensor should have measured at, but it didn't matter because the meter read nothing. It was a cool assignment though I can now say I know how to test wheel speed sensors, something I could not have said the week before.

Another one of our assignments was to color in the schematic on the left. This would be the schematic we would use to help instruct some our newer class mates on wiring up light boards for what would be our final. Me and my group spent a good hour and a half talking and discussing the right way to color in the diagram. After some time and a little help from another one of our peers we were confident that we had the schematic colored in right and would be ready for the light board.


I think the thing I can reflect the most on this last week was how important the ability to discuss and work as a team can be. We sometimes tend to ignore others input due to our own confidence. This can be a great downfall if you are wrong in what you think. For me it was the simple mistaking a relay for a switch while coloring our wiring diagrams, I was so confident that I had it right and my group had it wrong that I had to go verify with another group and guess what I was the one who was wrong. This is where if I would have just put my ego aside I would have understood what my group was saying and not have been the jackass.

Week 3
Hours 18
Quarter Hours 52

"Relays, Diodes and learning how they work"

During the second week of instruction my instructor began to bring up relays and diodes. I remembered a lot about these things from a couple of previous electrical courses but just like everything else if I'm not using it or studying it it tends to go to the back of my brain. Needless to say I had some relearning to do. My instructor gave some really good lectures on relays and and what they are used for and also how they work. During our lab time while working on our relay test boards he also came over and began talking about diodes and what they are. He then showed me and several other students how to test a diode using a multimeter. Along with the class discussions and conversation with my peers, There were a couple of videos on you tube that helped my understand how diodes and resistors work.

 Below are pictures of me testing a diode using a multimeter and in this case on this test board there was an open diode.

Here are a couple links to some of the videos that helped my understand what was really going on inside a diode and a resistor.
www.youtube.com/watch?v=DUiNq7P...
www.youtube.com/watch?v=JBtEckh3L9Q‎

Here is another link to how light emitting diodes work.
www.youtube.com/watch?v=8quZrUcRFlw‎‎


This last week I also had the task of continuing to test switch boards, this time the boards had relays on them. What we were looking for on the boards was open circuits, high resistant voltage drops and shorts. I found this to be difficult at times and pretty straight forward others. It was another one of those things where I had to keep track of the steps I was taking and make sure I was going in the right order. When I did that things worked out fine. Below are some picture of some of the testing I was doing.

 In the pictures above I found an open circuit on the + side of the circuit. this was just one of many boards tested.

I think the thing I can reflect the most on the most over this last week was some of the discussions I had with some of my peers while working on test boards. I would here someone say "oh it's a bad relay on this one" and for some reason several times I asked different people that would say this, "well why is it bad?". This would prompt a discussion. This is when I feel that my understanding of relays and diodes and how to test them came to help me understand more about them while hopefully helping someone else with the same. It seems to me if some thing is broken I can probably fix it but I  also feel I have an obligation to try and figure out why it broke or isn't working. WHY, WHY, WHY

Week 2
Hours19ish

WK 1"finding open circuits, high resistent voltage drops and shorts"

Spring quarter just started and we are jumping right into Electrical. During the first week of instruction we began talking about current flow, had a nice discussion and exercise on electrons and how they flow. We also talked about resistance in which Jeff gave us nice demonstration by burning up some wires. It was a great beginning to the quarter. We also discussed Kirchhoff's law and said our prayer many times, "no current flow, no voltage drop!!!!"  Our assignments for the first week mostly had to do with determining whether or not we had open circuits or high resistance voltage drops on light and motor test boards.

Above is a picture of a light board with a HR/VD or high resistance voltage drop which I was able to located on the power side of the circuit. Below is two pictures of a similar test board which had an open circuit on the ground side that I was easily able to identify.

Apart from just doing light test boards we also worked on finding similar problems on motor test boards which a basically the same thing. how ever at the end of the week we were asked and shown how to locate short circuits on test boards both light and motor. At first I thought oh this will be much easier than the last time I had to do this and it was. I'm not saying that shorts are easy to find but going through similar motions with a better understanding made it much easier this time.

I think the highlight of my week was being able to help others understand the electrical we are studying a little better and maybe learn a little from the help I was able to provide to some of my peers. The main thing I learned during this week was that when some thing seems to be working just fine and you cant find the problem even though you know there is one, is to go back to the beginning/the basics. This came about when I had a problem with a motor test board, the problem was that everything seem to be just fine. My first though was oh this test board must just be a joke, I went and grabbed my instructor for some help. He came out asked what the problem was and I told him. He switched the first switch on the board that was supposed to open the circuit and it didn't. He simply looked at me and walked back to his office. I think he saw the look on my face, the duh look. I new right away what the problem was, me not starting out in the beginning/ the basics.

WK 1
Hours 18

"More work on the 1998 International project"

So we have gotten almost to the end of the 1998 International project. Since my last update we have managed to cut off about half of the rear part of the frame, fabricate legs with casters allowing us to roll it around.

We had our instructor order us two 8" heavy duty casters with brakes that would fit our 4" square tube legs. They did, after that it was just a matter of drilling 2 holes in the frame rail (thanks Jeff) we were able to bolt the legs on too the frame. It definitely rolls but not with out some pushing.





One of the other things I was able to do was to eliminate lots of loose sensor and other computer wiring off
 the engine3 and tidy up the wiring we need. While doing this I was able to attach ends that would allow us to probe different parts of the computer allowing us to see what is going on inside if need be.

After getting rid of the extra wiring I was able to find a good mounting spot for the pedal on the frame rail where the cab used to be mounted. I then began the task of finding and fabricating a panel to mount the key switch. After find an old piece of aluminum and drilling a couple of holes I was able to bolt it right on the side of the engine.

There is still more to be done but a lot less than there was a couple of weeks ago.

Week 6 "Making The Stone True" & "Sharpening Drill Bits"

So one of the many things I learned this quarter was how to true or dress a grinding wheel. It wasn't hard to learn or understand it was the simple fact that I had never actually seen a grinding wheel dressed or even tried to myself.

The tool I used to dress this grinding wheel is called a grinding wheel dresser/ dressing tool. Its a very messy job, there tends to be a lot of dust. However it does not take very long considering your wheel isn't to bad. if it is I would recommend a respirator.

 One of the reasons we were shown how to properly dress a grinding wheel, was so that we would have a even grinding surface for sharpening tools. Specifically a drill bit.

The drill bit I sharpened because I actually needed it for another project was a 13/32. it wasn't to dull when I began so all I really needed to do was crisp up the edges. I did not use a bit sharpening tool, I just used my hands. This went smooth and was very simple. However what I didn't know and had to look up was what angle in degrees the tip would need to have to perform properly. After watching one youtube video and checking a couple different web sites I found that it needed to be at 59 deg.

Even though this was a pretty simple and small task I now know how and feel comfortable at dressing a grinding wheel and if my drill bits dull in a matter of minutes I will have it sharpened correctly.

Week 4 "The Difference Between Lubed and Unlubed Fasteners"

During the last week of class we were given a short demonstration by our instructor on determining the  highest clamping force compared with the amount of ft. lbs. used to get it there. Using the set up below, we were to test our choice of grade of bolt and put it in this 50ton jack pre-load the fastener using the jack and take the fastener to failure while recording the ft. lbs. of torque and the corresponding clamping force.

 I chose to take 2 grade 5 half inch fasteners one lubed, one not and start out at 50 ft. lbs.and take each bolt and add 25 ft. lbs of torque at time until each failed.

 I was able to take both the lubed and non lubed fasteners to over 125 ft. lbs. of torque and over 15,000 pounds of clamping force. The difference being that it took less ft. lbs of torque for the lubed fastener to reach a higher clamping force than the non lubed fastener. For instance at 131 ft. lbs just before failure the lubed fastener had a clamping force of nearly 17,000 lbs, where as the non lubed bolt only reached 15,350 lbs. of clamping force with over 150 ft. lbs. of torque. It was easy for me to see the point of this assignment and I enjoyed doing it. That being said, with a lubed fastener you will reach a higher clamping force with less ft. lbs. of torque applied.

Week 4
Shop Hours 17
Total Running Hours 87ish

Week 5 The progress on the 1998 International project "Its Alive"

Over the last week we have made great progress on the International project. We were able to test the engine and determine that it was indeed turning over. We then set out on a mission to hook up the fuel lines and loop our coolant lines by bypassing what would be the heater core and start working on the electrical. The coolant lines and fuel lines were easy enough, however the electrical wasn't so smooth.

 The first problem I ran into was finding all the wiring connections we would need to get the key switch to work, power up the computer so the engine would stay running assuming we could get it running and hooking up the throttle pedal. After spending most of my day in the shop and some time with my instructor we were able to find everything we needed left over from the scrap of the truck

With a lot of learning and researching of schematics we were able to get power to the computer, the throttle pedal working and the key switch barely working. We were able to get the engine running and to stay running, the only problem being the engine would only stay running with the key in the start position. As soon as you released the key the engine would die. We were fairly quick to determine that we had a mix up in some wires at the key switch. We were then able to go back fix the problem and had the engine running at a good idle for several minutes. There was a lot learned this last week, for me it was all about the electrical side. With a bit of help and instruction I broke down the electrical schematic and was able find and put power to everything on this engine that it needs to run.

Week 5
Shop Hours 19
Total Running Hours 110-115