BW 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.

He also pointed out that there seems to be a bit of debris caught under the 1000 grit sandpaper that is scratching the fibers.

I fused four fibers with lips, one with each possible orientation of the lip. Front top and bottom are the positions closest to me as I was fusing and back top and bottom are farthest from me.

After having a Google Hangouts meeting with Dr. Jones and Jim, I started trying to push just until the clamps started to move. They are supposed to stop moving when I let go. I have not seen that happen, though. The clamps do keep moving as I suspected. But I might be pressing too hard or too long. I might not notice exactly when the clamps start to move.

6/8: I forgot to test the splicer before using it. Fortunately the ferrules did not slam. I will have to be more careful in the future.

6/11: I want to make a plan for fusing. Today I had some problems at the beginning but as I went on my fibers were strong enough and looked reasonably transparent. If I am getting good results like this, I want to move on from practice.

However, sometimes when I thought I was ready problems arose and I changed my mind. Last week, I had a string of successes and I thought I was ready, but then a series of failures stopped me from moving forward.

This week, though, if I let the machine do most of the work I may be able to avoid a long string of problems.

I do need to address some questions, though.


 * Should I measure the sci-fis before fusing? Is that something we have done in the past but don't need to continue or is it something that is still essential?


 * Is my plan for spares all right?


 * Do the fibers need the same testing configuration as in the pre-fuse tests?


 * If I make a bad fuse, I need to do some good practice fuses before continuing. How many should I do?


 * Where will I put light guide bundles after I take them out of the storage box for fusing?


 * Where will I cut off wings?


 * How will I have clean surfaces ready for the fibers?

I should plan what I need to do before and during fusing:


 * Clean the scrap fibers for use as we are fusing the replacement fibers. Set aside scrap fibers that have unacceptable adhesive residue.


 * Clean the splicing unit, especially the clamps and ferrules. Keep them and the surfaces that would be in contact with replacement fibers clean.


 * Clean the replacement fibers before fusing them.

6/12: Yesterday I finished polishing the scrap bundle end Andrew was working on.

6/13: Today it seems that any lip, no matter how small, is ruining fuses. The first fuse is incomplete and dimpled, and the dimple does not go away. The corners are not perfect either.

I think I need to start putting the fibers in the right orientation when there is a lip. That will be more difficult than my normal practice using the tape, but it is possible to do. Maybe I will need to record which way the tape is facing on the first fuse so that I can turn the fiber over correctly for the second fuse.

To remove wings, I can hold the wing pointing up vertically and scrape going both ways.

6/18: I am starting to fuse bundle 404, and I will be starting with Sci-Fi bundle 3.