Fiber novice makes progress

As I said in my original missive 4 months back, this really belongs in something like comp.lan.fiber, or sci.fiber.basics but there are no such groups.

Starting from more or less nowhere, I've gotten fiber strung across my campus (with some help, and donated fiber) and fiddled around with getting equipment racks in place at various buildings. Yesterday I trimmed and stripped 156 fiber ends and today I finally gritted my teeth, popped the separator on a pack of epoxy, loaded a syringe and got down to business making connections. Epoxied and baked 16 connectors, cleaved and polished 12 of those. My back is in knots from stress (hours of fiddly work), but the job went better than I had any right to expect, given that up to this point fiber connections and I have only had a "book and web learning" association.

Did not break any fibers while getting them into connectors. Actually only broke one while stripping 156.

Getting the bead of epoxy through the ferrule proved easier to manage (enough, but not too much) than expected, while getting the right amount into the back part of the connector while withdrawing the needle was harder, with nothing to see and so little volume used that the graduations on the syringe were not any help.

2 gram epoxy packs were more than enough - despite a heat-cure-only epoxy with a 4 hour pot life, it still claimed only a 45 minute syringe life - I think it was about 1.5 ml and I probably only used 0.5 ml of it

- perhaps next time I'll try leaving "about half" in the package after mixing, and see if I can get two syringes of use-time out of it. 4 gram pack would have been an utter waste.

Some of the cleaves were a bit too much (fiber snapped while being scribed) but they all look good when polished, so evidently none managed to fracture down into the ferrule despite my poorly calibrated scribing force.

Was very happy to have gotten a microscope with dual mode (Oblique/coaxial) lighting. For a complete novice, scoping the fibers as polishing progressed was helpful, and with singlemode fiber only one of the two modes (oblique) shows the core. Both are good when checking for dirt and scratches, as they highlight different things.

Should get easier from here.

Reply to
Ecnerwal
Loading thread data ...

Well done.

Cheers

Phil Hobbs

Reply to
Phil Hobbs

Ah, polishing fibers on college campuses! Brings up some nice memories of having a few thousand SM ends done one summer.

16-24 connectors is all you can do from a pack of epoxy due to the syringe needle clogging up (I think you write about it further down) and the oven capacity. Which oven do you have, BTW?

A player (with good headphones) with some low tempo music or an audiobook on some light subject works best to to keep stress at bay. "Rise and fall of the Roman Empire" and Pink Floyd (lots of) kept me going for a few months.

Heat setting epoxy is the best type for someone just starting out - no time pressure (like 1 min for anaerobic type) usually makes the process go much smoother.

Apply pressure to the syringe and wait until the bead of epoxy is approx

1/3rd of the diameter of the ferrule, then keep the pressure on the syringe (so it won't suck the epoxy back in) and withdraw the needle

Good idea but I don't think it'll work too good because its viscosity in the package during that time will increase to the point where it will be hard to squeeze through the needle anyway. I never tried though because extra epoxy was always at hand - most of the time we had left overs from other jobs and some were approaching shelf time so needed to be used up anyway. I'd be interested to learn about the outcome if you try.

This is the part that requires most practice and the scribe always has to be sharp and preferably new. If you can, get a new one every 1000 or so cleaves - they are not terribly expensive and a sharp one makes a log of difference. Again, heat-setting epoxy is best for a novice because it forms a protective cone at the tip of the ferrule that prevents the crack from going too deep. Makes for a bit longer polishing but less ends need re-doing due to bad cleaving.

Did you get a microscope with an optical laser safety filter? Can be useful if students start getting involved in helping with IT - never know what's shining into it from the other end. I can sort of see ends energized at 850nm as a dark red spot but 1300 and up - no chance to see what's coming at you. Fluke's FT140 with a safety filter can be very useful in alleviating the fiber technician anxiety :)

It definitely will! First 156 are always the hardest! ;)

My email should be decipherable, feel free to drop a message if you need do discuss any part of your project. I understand you're braving the whole thing in DIY mode, so I'd be happy to help if I can.

Good luck!

------------------------------------- Best Regards, Dmitri Abaimov, RCDD

formatting link
Cabling Guide, Cabling Forum, color codes, pinouts and other useful resources for premises cabling users and pros

Reply to
Dmitri(cabling-Design.com

Looked at your post from 4 months ago and realized you are doing LC connectors (I think it sounded like a final choice back then anyways). So, with these little ones you should be very extra careful not to inject too much epoxy - they are susceptible to a very inconvenient problem whereby the epoxy can get out of the ferrule and onto the spring and glue the spring and ferrule frozen. This makes the ferrule no longer movable and, although it can still mate with a good, spring-loaded ferrule of a factory-made patch cord, it won't mate with another frozen one. That makes the issue harder to detect until you need to make that one important connection between two ends both of which you connectorized. Found that out a hard way, so watch out!

------------------------------------- Best Regards, Dmitri Abaimov, RCDD

formatting link
Cabling Guide, Cabling Forum, color codes, pinouts and other useful resources for premises cabling users and pros

Reply to
Dmitri(cabling-Design.com

FIS - got an old one (but it's the same as the current model other than the block) with a connector block for what looks like 8 FDDI, and bought an LC connector block (24 holes, FC/ST/D4 on the back side that I never expect to use) new from FIS. Shaving a few dollars to help my tiny budget survive - the used one seems to work as well as a new one (which would be used by the time I was done with it....)

I did try this, and it did work (40 LC connectors from a 2 gram pack, and I still had epoxy left in the syringes.) Mind you, the epoxy data confuses the issue; one chart says 45 min syringe, another says 90 min syringe, both say 4 hour pot. This is the FIS quick-cure (heat cure only) which sets in 5 min at 100C (and turns from amber to red, nice touch so you know it's cured) though I have been belt-and-suspendering it to stay for at least 15 minutes after the last connector, as I don't have more than 24 (that I'm actually connecting right now) at any one location anyway. I suspect the pot life is quite conservative, actually, and yesterday I split the package but never even opened the (mixed) second half, as the syringe was working fine for at least 90-100 min. The remainder is about like honey today.

That may be (from the MSDS) Epo-Tek 353ND, just packaged conveniently.

I have enough bad personal (non-fiber related) history with superglue that I was not too interested in going that route, even though it meant having to buy an oven. As it turns out, that has been for the best, I think.

Scribe is brand new, carbide. I got no responses to my query about why there are ruby and sapphire scribes, and why would I want one .vs. carbide, so I got a Panduit carbide because all the fancy scribing machines use carbide wheels, Panduit is a decent brand IME, and it was cheap at Amazon (the fact that it costs less & looks about 9 times better than the cheapest thing FIS sells was gravy, though largely irrelevant.) Had 12 scribes on it at the end of the day I wrote the above. Won't hit 1000 on this campus - if I did, even with my tiny budget, I could afford a new scribe or replacement tip if I could find it for less than the cost of a whole new scribe (I hate it when prices are not logical.) Of course, with used diamond abrasives available, sharpening it would also be possible...

The polishing time (getting the epoxy blob off) is not very tedious, and beats the heck out of having to do connectors over.

Yes, it (FIS Compact) has a laser filter (I'm at 1310), but one of the upsides of a very small operation is that the far end of the fiber is locked, and I have the only key. So long as I don't get stupid/careless, I won't have live fibers.

Actually, after that first day doing 16 it got much better, simply from knowing what I was up against in practice, rather than merely in theory. I was, for instance, far more worried about breaking a fiber off in the connector than has turned out to be warranted by actual experience, since the possibility had been mentioned in several sources (along with the checking that it wasn't by making sure the tip would pull back.) Got a work flow sorted out and could approach it with more calm.

I've been checking to make sure the ferrules move when I'm done. Some are a bit stiff, so I have at least partly had this problem. I think I have a better feel for it now. I spent some time waffling (or covering options) due to a possible donation that did not happen, so I'm sitting on 100 sm SC connectors I won't be using, but everything I'm installing is LC.

Reply to
Ecnerwal

These ovens will outlast you and me - getting a used one was a prudent choice.

BTW, if you are pinching pennies, FIS may not be the least expensive option. They are good and the selection is very nice but for absolute lowest prices we've found Kitco (

formatting link
) to be a good balance between price and quality. There were some quality issues way in the past, but it's a great product now.

This is very much dependent on the ambient temperature, too: at factories where they connectorize patch cords, I've seen them keeping mixed packs literally on ice (in portable coolers as it were) for the duration of the

8 hr shift.

Now I'm thoroughly confused: when you mix epoxy and hardener (remove the separator, use it to squeeze the plastic pouch back/forth until the entire content becomes mixed and evenly colored - red), there are no longer any halves - the etire package contains the same mix. Were you trying to mix only parts of the package? I don't know how this could be done and it sounds like a recipe for disaster anyway. Do you literally separate (cut with scissors for example) parts A and B before they are mixed, then mix in a cup of some sort? I wouldn't do it because they are accurately proportioned for the size of the whole package. But then, again, maybe I just misunderstood.

Definitely for the best - the heat curing epoxy is also much harder than other types and polishes better and make a much better yield, even for an experienced installer.

Hmm... I thought I responded back then to the scribe question, well, too late now, you've made the best decision on your own anyway.

You never know - fibers get mixed up, equipment gets turned on/off accidentally (I've seen equipment sitting in the closet, turned on for 5+ years before someone cared to investigate what it is and why it's on) and additional people get involved (but not until you've finished all the hardest parts :) )

LCs are nice but give a lot of grief to some of us with, how should I say, less compact fingers (and shorter nails), especially in high density cross-connects. I've taught a class on installation and witnessed some people were unable to handle such a small part and I've had some less than fun time myself trying to disconnect LCs from high density panels. So, from this point on in your college all IT recruits would have to pass dexterity tests before getting hired :)

Cheers, D.

------------------------------------- Best Regards, Dmitri Abaimov, RCDD

formatting link
Cabling Guide, Cabling Forum, color codes, pinouts and other useful resources for premises cabling users and pros

Reply to
Dmitri(cabling-Design.com

They are good for some stuff, and close by. When I thought I was buying cable they looked phenomenal compared to everything else I looked at (prices per meter as good as or better than prices per foot for equivalent cable.) Some stuff they are absurd about - the scribe already mentioned, Kevlar shears and pucks all came from Amazon after price comparisons. Their pucks are 3 times the price of Paladin pucks from Amazon, and I can't quite imagine that they are 3 times as good. A bunch of stuff I got from *B*y. And I had some useful donations - a huge one from ADC, and smaller ones no less appreciated from 3M and Ripley.

I just took a quick look at the kitco site, and NO. Sorry, I can't stand dealing with a website that won't admit to a price (and I've generally found them to cost more than ones that will admit to a price when I have asked - I did a _lot_ of that at the beginning of this project.) Every item I looked at wanted me to submit a quote request to find out how dearly they cared to sell it. I don't have much, if anything, more to buy at this point anyway.

You just misunderstood. I was trying to make that clear with the (mixed) above, but evidently failed. I mixed the whole package. I divided the mixed epoxy and put the clip back on before loading the (first) syringe. In the case that there's a second syringe later, I load it from the other half, later. Yesterday, I never used the second half - that is what's gotten to "honey-like" consistency today. Just trying to milk the "pot life" .vs. "syringe life" aspect a little. Ice would also make sense for the second half.

I think you did, but it may have been after I already had made up my mind while nothing was coming in for a while after I pitched that stone into the waters.

I turned off a phone line this fall that had been disused (but costing $50+/month) for 2 years. Additional people is remotely possible, but pretty remote. But I'm glad to have the filter in place, even if I never need it.

They make tools (ie, Skinny Fingers, et al) to help the finger-enhanced, which seems better than not hiring people due to physical characteristics that can be overcome with assistive devices. In my case I avoided cross connects, so they are all easy enough to reach - if they were not, I'd add a tool to the bag. The part where I need to fiddle with which glasses I'm wearing depending on what I want to look at is already in full swing for me.

Reply to
Ecnerwal

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.