BW February 2018

2/1: Dr. Jones said we do need a light guide bundle highly polished on both ends for calibrating the fiber testing equipment. I chose bundle 406 with the black strap and got it on the polishing plate yesterday, but it was not yet aligned. This morning I aligned it as well as I think it will be. I think it needs just a little polishing with 1000 grit to get all the fibers to be exactly in one plane. Since the fibers on the left side are sticking out a tiny bit less than the rest, I want to twist right in front and left at the rear of the polishing plate.

2/2: I finished polishing bundle 406 upstream so we have a bundle highly polished on both ends.

I also reviewed the fiber testing equipment so I will be ready to discuss it next week. That way I can show what I know and learn what I need to.

2/5: I did some fusing practice, and the strongest fuse that I measured held 1200 g plus the hanger. It broke under 1300 g and the hanger. Dr. Jones said wings are unavoidable, and I should remove them with a razor blade, not sandpaper.

2/8: Jim said I should keep a separate logbook for fiber testing. I should include links to the histograms of run results and also to the text files (maybe on Gluey?) that can be opened with a spreadsheet. Once I test fibers, they should remain in the same bundle position for all subsequent tests. I should note anything unusual, such as fibers that need to be sanded to go in the chimney or fuses that break.

I told Jim about the leak in the splicing unit that Ann Marie mentioned to me. He found that it was coming from a hose connection. He tried to fix it, but the connector broke and we will need to order a new one.

I did six or seven test runs this morning with the dark box. After run 1359, they stopped completing. Jim looked at the cron.log and said things were hanging there. My test runs would not complete if I used the commands in the browser. He also said the relative pulse normalization should not be zero. I had not noticed that it was zero. The results looked fairly good otherwise. The only unusual feature I noticed was an isolated spike sometimes appearing near the highest part of the plot. It reminded me of a TV or radio antenna on the slope or at the top of a hill.

2/9: I asked Jim to get me started on fiber testing. He can do that tomorrow. I also requested 0.188" washers for aligning sci-fis. I would like to find the knife for removing extra material and burs from the printed parts.

Jim showed me that the scraper knives are in a desk drawer in room 403. I removed some excess material from the sci-fi collar that was on the desk in 403.

Then I put 400 grit paper on the polishing wheel to get ready for polishing sci-fis.

2/13: I removed excess material from the sci-fi collars and washers Jim printed for me yesterday. Then I realized the holes in the washers were too small for the screws. Jim said the washers should not be tapped, but the holes can be enlarged with the round file. I tried doing that, but I did not get the hole bigger with the round file.

I swept in lab 405 and cleaned around the 3-D printer. I also requested a pick-up for two boxes of used batteries and the contents of the sharps container. I found a page on the UConn website about Responsible Conduct of Research training.

2/15: Jim showed me how to drill the holes in the sci-fi collars using the drill press. He explained the major and minor diameters of a screw. The major diameter includes the threads but the minor diameter is the narrowest one at the deepest point of the grooves between threads. We can measure the major diameter easily with a micrometer, but the number of threads per inch is harder to tell.

A screw number such as 4-40 means that the screw size is 4 and there are 40 threads per inch. When drilling holes to be tapped, they should be a little larger than the minor diameter and less than the major diameter. The tap hole needs to be larger in harder materials such as steel or iron than in softer materials such as brass or aluminum.

Clearance holes are larger than the major diameter and they can be either a close fit or a larger free fit. For the washers we used the free fit.

Another useful tip is that there is a little knob for locking the micrometer.

When drilling I had to go slowly and back the drill bit out as needed. I am still not really sure when to back it out, but I did it for every washer I drilled. My best drill holes seemed to be in the last two washers. They did not have much material projecting after I was done.

Here is the drill user manual.