Sunday, October 28, 2012

Oct. 22-26, 2012: thermostats and sensors!

This past week I did the day 24 assignment. I took three thermostats and dipped them in water and watched them open as the water got warm. It turned out that two of them opened at the right tempatures and the last one was open at room tempature. I also did some dial indicator measurements. I measured flywheel housing run out and flywheel housing bore run out. The housing measurements were 12, 9 and 6 thousands of an inch which was in specification. The bore run out was 3, 7, and 5 thousands of an inch which was also in specification. I was almost done with the cylinder liner protrusion. I finally understood it and how to measure it. I hope to finish the measurement and crank end thrust this next week. I also finally got my sensor to work after figuring out which wire does what and was able to see with a multimeter. Very cool to see it work. I also got to see some other people's like the differential pressure sensor. You blow in one side and the voltage goes down and blow in the other and the voltage goes up. I also had a few theories about the bearing failure analysis. I thought it was a hot short or oil starvation due to the amount of bearing that was worn away and the pieces missing, but after talking with Jeff and learning really what it was it made complete sense. I won't spoil it, but I learned a great deal this past week and I can't wait for what's next.

Hours: 45
Hours to date: 259

Sunday, October 21, 2012

Oct. 15-19, 2012: The V16 Cat

This past week I got to work on a cat engine. Part of the assignment was to remove one of 16 cylinder heads and remove the piston and cylinder liner. I learned a lot about big engines when I did this. I had no idea how a cylinder liner worked. It made so much more sense when I had it in my hand. I also did a little troubleshooting with my truck. It has been having some starting issues. As you can see in the pictures the flex plate teeth are starting to wear away in a couple of spots.

45hrs
Hours to date: 214

Wednesday, October 17, 2012

Lethal Strike Video

Oct. 17, 2012
Today I watched a video called "Lethal Strike". The main idea behind the video was trying to show oil injection injuries. It showed a mechanic doing some failure analysis work on a front end loader that had a hydrolic leak. He reached his hand in to find the leak and got injured thinking it was from the steel braids that the hoses are made up of. He said it felt like getting bitten. It turned out that he had 3000 psi hydrolic oil enter his hand and build up pressure resulting in constriction of his nerves and arteries. They had to remove his index and half of his middle finger. The "take way" from this video was no glove can protect you from these sorts of injuries and no matter how small the injury, make sure to bring it to your supervisors attention.

Sunday, October 14, 2012

October 8-12, 2012: The Kubota

This week I was able to take apart a 3.3l Kubota engine. I got to learn a lot about this engine. I hadn't adjusted valves in awhile so it was nice to go over that again. I also learned about balancing shafts. They are designed to "quiet" the engine. Really cool to see and learn about. I also got to see all the timing marks on all the different gears on the front of the engine. Makes a lot more sense how everything works.

45 hrs
Hours to date: 169

Tuesday, October 9, 2012

October 1-5, 2012: the "O" scope and high resistance connections

This week I learned how to use an oscilloscope. It is designed to observe constantly varying signal voltages. The idea behind it is to understand how an electric motor is working by studying how it's components are working together. I also learned more about diagnosing bad connections. I was doing a load bank test on a welder and as soon as I finished I removed the leads from the welder and one of them was very hot. Turns out as you can see in the picture it was a bad connection and it was altering my readings.

34 hours
Total to date: 124 hours

Monday, October 8, 2012

Sept 24 - 28, 2012: Generators and Hydraulic pumps

This week I learned more about how experience is key. We had a skid steer that would turn on, but no movement and no hydraulics. It turns out if you look at some pictures that the flywheel and the pump input shaft was stripped. I had some ideas about what was wrong, but as soon as they had told me it had happened before I realized how important experience is. I also learned about different designs of generators you can see one of them in a picture of a Genie S65 boomlift. It is a hydraulically driven alternator for the basket so you can have 115v ac current without an extension cord like the other models.

45 hrs
Hours to date: 90hrs