Week 5 "More sensor testing and the progress on the Detroit 60s assigment"

During this last week of class we spent a lot of time watching our instructor disassemble a 4.5 John Deere engine that had a hole in the side of the engine block. Neither our instructor or anyone in class had been inside this engine to see what exactly had happened. So we spent a couple hours each morning learning the proper way to keep foreign materials from entering the engine while disassembling. He was also careful to show us where to start our failure analysis for this type of engine failure.

We all had our own suspicions on what had happened and it turned out to be a broken stabilizing shaft. As to what caused the shaft to break, that is still an on going investigation.

We also had an assignment given to us that had to do with different types of sensors found on a Trucks or heavy equipment, explaining how they work and showing how they work using either a digital multimeter or a scope. Since in my last blog I posted on the testing of a ABS wheel speed sensor using the shops Modis and big screen, I figured I would test a temperature sensor using a digital multimeter.

In the left picture you can see that the temperature sensor has a certain electrical resistance at a certain temperature, it happened to be 10.816 ohms at shop room temperature. Now as we move right you can see in the middle picture that as soon as I pointed the heat gun on the sensor the electrical resistance changed in proportion to the change in temperature. In the picture on the right you can see this sensor had the same result when heat was taken away only in the opposite fashion.

Me and my group also made some great headway on our assignment on the Detroit 60s. Below are some pictures of some of what we managed to get done.

My group and I managed to get everything disassembled from the engine that we needed to, to be able to start taking all of the assigned measurements the following week. After spending several long hours staring and searching I was also able to find and print off all the specifications we would need to know if what we are measuring is in or out of spec.The link is below.

 http://www.kenmartransport.com/detroit/Series_60_Service_Manual.pdf

I think the thing I can probably reflect on the most over this last week, is how important the ability to to pay attention to detail is. For me this came up several times, once was when I was trying to explain to a fellow group who was having trouble removing the head from the engine block. They were using a hoist which should have picked the head right off the engine block, but for some reason wouldn't. They were 100 percent positive that they were completely unattached from the engine block but the head wouldn't come all the way off. It wasn't until someone actually wanted to hear what I had to say before I was able to show them, that no the head wasn't attached to the block. And that there problem was one little bolt head off the timing gear assembly that wouldn't allow them to remove the head. One little detail had 4 or 5 people tearing there hair out for a few minutes.
I also had the opportunity to remove a cylinder liner out of an engine. Something I had seen done but never had done myself, it was some what simple but new all the same.

Week 5
Hours 22


 

Week4 " Truck and trailer lighting test board test and scoping a working ABS wheel speed sensor"

I started out week 4 of this quarter preparing for our final exam for the electrical part of the quarter. We were separated into teams combining 1st and 2nd year students and were given the task of wiring up mock truck and trailer test boards. We were required  to make all lights, switches and relays properly function with out blowing a 1 amp fuse. We were not given a time limit how ever we were timed. Me and the group I was teamed up with managed to finish in 2 hours and 10 mins. We blew one fuse, yet we found the problem and were able to make everything function properly in the end. 

 These are the test boards we tested on. It was a fun yet frustrating test, but I can truthfully say I walked away with a little more confidence and understanding of what we had just done.

 Another thing I did this last week was test a working ABS speed sensor that was still attached to the wheel assembly. The reason I did this was that in week 3 we were all given different types of sensors by our instructor and asked to find out what type of sensor it was and test if possible. Now in my last blog I explained what type of sensor this is and how to test it. The thing was my sensor was bad and I wanted to test a good wheel speed sensor.

So I spent some time after morning lecture hooking up the Modis to one of our practice axle assemblies. below is a picture of my test leads hooked up to the sensor.

 The first test I performed was to graph the signal using the multimeter function on the modis, and below is what I was seeing when I spun the wheel.

After accomplishing the task of hooking up the modis to the sensor and actually testing it and seeing the signal. My instructor then asked me to put it up on the big screen and use the lab scope function on the modis instead of the graphing multimeter function.

I was able to connect the modis up to the big screen easily, I found the hardest part was finding the right settings on the modis to get and be able to read a clear signal. With the help of Travis our instructors assistant, I was able to get a really clear signal.

Another one of our assignments in class this last week. Was our instructor asked each group to go out into the shop and decide on an engine that we as a group would like to work on. We would be removing the cylinder head, 1 piston, 1 liner, 1 cylinder of valves, injector and measure the crankshaft rod bearing journal. My group decided on a Detroit Series 60, the one in the picture below. I am really looking forward to this.

My reflection for the week comes right back to one of the biggest problems I think we can have, communication. Previous too and even during our final exams on the light boards, I was having problems with my group. One half of us wanting to go about it one way and the other half a different way. At first we had one part of the group going off of a paper schematic while the other half was going off a completely different schematic. The problem wasn't that one half of the group was right and one was wrong, both sides would have succeeded if they would have gone about it at separate times. Instead we tried to do two things at once and when we thought we were done, we weren't. We had only manage to waste an hour and blow a fuse all due to the lack of communication. I was remind once again that one of the biggest keys to staying on track and properly completing a task while in a group or team setting is to have an open line of communication between everyone.

Week 4
Hours 16
Quarterly hours 73ish

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.