Difference between revisions of "BW June 2018"

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We can try sandpaper or copier paper to remove the lips before fusing.
 
We can try sandpaper or copier paper to remove the lips before fusing.
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Jim advised measuring the fibers to check on what friction there might be between the ferrules and fibers.

Revision as of 15:13, 7 June 2018

6/4: I practiced fusing today. For a while I was getting adequate strength but also wings. I would like to start fusing, though, and test a bundle to see if wings really matter. If we remove them and the fibers work, I think there is no reason to complain. If we run into problems with the first bundle, it won't be a major delay. We can cut off bad fuses and redo things.

I need a list of things to do next.

1. Ask Dr. Jones about the lips and why they would interfere with fusing.

2. Explain what happens during fusing in more detail.

3. Find out how to drain the Campbell Hausfeld compressor tank.

4. Start cleaning sci-fi bundles with the new lint-free cloths.

6/5: I'm not sure what is going on with the splicer.

By itself, as long as I give to brief pushes as the process is starting and sometimes a sustained downward push too, the splicer has often fused without creating wings, but the fuses are usually weak. They may hold 850 grams but break at 1050.

Usually if all I do is push down the top ferrule and push the long fiber to the right at the beginning of fusing, the gripping clamps do not bottom out. They often move partway to the right but do not bottom out.

Lips at the end of a fiber cause incomplete fusing if the splicer does all the work except for my two initial pushes. This is strange because the lips do not project beyond the end of the fiber.

If I push on the long fiber during heating and cooling, the gripping clamps are more likely to bottom out at some time. The results from my extra pushing are quite variable. Even if I push fairly hard, the fibers are sometimes weak and break at 850 grams, although they may have the kind of wings that used to imply adequate strength. However, pressing too hard creates huge wings that are too thick to cut easily. It is easy to damage the cladding while removing the thick wings.

6/6: I am wondering about the effects of friction between the fibers and the gripping clamps and between the fibers and the ferrules. I think Jim said that there is a little more than enough space for the fibers between the ferrules when they are mated. If that is so, there should be a lot less friction between the fibers and the ferrules than between the fibers and the clamps.

But if for some reason the extra space is not there and the ferrules are putting a tighter grip on the fibers than we thought, the ferrules might be resisting the force of the clamps that should bring the fibers together.

One way to test this idea is to turn off the heating lamp and put a scrap in so that it goes through the clamps and partly through the ferrules, but not all the way to the end. We can do a run and see how much the fiber moves toward the end.

Today I emptied the Eureka Airspeed vacuum cleaner dust cup. I also rinsed the filter screen and the dust cup. I dried them with paper towels and left them out to dry at least overnight. I put the filter next the splicing unit for safekeeping. I think it will be out of the way there and it will not get anything dirty.

In retrospect, I probably only needed to rinse the filter screen. Next time I clean it that is what I want to do.

6/7: Jim explained what he thinks is happening with the lips. The cladding gets stretched as the wheel turns, and material gets caught between core and cladding. When the ferrules come together, the lip is pushed so that it sticks out beyond the end of the fiber, and the material between the cladding and the core also leaks out. These extrusions prevent adequate contact between the cores. The stretched cladding and extra material melt first between the fibers, so there is a smaller fused area, and the presence of cladding in the fuse weakens it.

We can try sandpaper or copier paper to remove the lips before fusing.

Jim advised measuring the fibers to check on what friction there might be between the ferrules and fibers.