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Comment by ocdtrekkie | Hacker News Reader

Maybe watching Comcast employees use a microscope when fusing individual fibers together when installing their service has made me feel like sticking my own connectors on fiber is a bad idea.

The thin diameter is a nice feature, but the ease of breaking them would keep me from installing them anywhere copper wiring provides adequate performance.

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People have to be careful when splicing fiber when every dB of loss is important, but modern fusion splicers make it pretty easy.

For just running between houses, I've seen links working over fiber that was cleaved with linesmens pliers before a crimp on connector was added.

So I searched up "fusion splicers" and apparently there are machines that automatically align the fiber and fuses them together, with only ~0.02db of loss. Does a human doing it manually with a microscope get significantly better results?

Fusion splicers are very expensive, under $10k is the cheap end. ISPs own them of course for field work but home installs are often done by small independent contractors (one-person companies are common) without the budget. The situation has improved a lot over the last few years, but historically fusion splicing was such a delicate process with sensitive equipment that ISP crews would pull around an air-conditioned trailer just to house the splicer and its operator. Actually these trailers are still the norm, but the machines have also come down in price and up in flexibility so they aren't so necessary any more (but I'm sure it still really helps productivity to have your tools on hand and not be dripping sweat on the workspace if you do this all day...).

But in any case I find it more likely the installer was using an inspection probe/microscope to verify a field assembly connector than actually splicing. Most field assembly methods don't require a microscope but it's common to use a specialized type of microscope to check the correctness and quality of the face of the connector before use, to avoid future callbacks, which said independent contractor will be penalized for.

Expensive if you need to be competitive with higher volume.

Old fusion splicers can be inexpensive. Tradeoff is they take longer to to do alignment and are much heavier than modern splicers.

I got a FSM-30S for sub $3k on eBay years ago. $350 for calibration. I see listings now for under $500. Paid for itself very quickly vs. hiring out as a little ISP. Wasn't hard to learn from YouTube videos and material from Fiber Optic Association.

FYI, brand new fusion splicers can be had for under a grand.

Fusion splicers are cheap. You can get a brand new fusion splicer for under a grand.

Fusion splicing hasn’t been a delicate process for at least twenty years and trailers are used only because they provide better working conditions.

Per-splice costs of crimps are higher, but startup cost can be lower. Tools for crimp are generally $1k or so and splicers used to be $10k+ (though now you can find new ones for sub 3k and used for lower than that). A mechanical splice can cost $10 in material while a fusion splice might cost $0.05. Consumables for a fusion splice is just a metal rod for heat shrink tube that goes over the fiber, then a metal rod next to it, and another heat shrink tube to hold it all together.

I haven't seen someone use a microscope to inspect a splice, but it is common to inspect the connector face because dust can significantly impact the link.

Fusion splicers are amazing pieces of technology. I used used to use one from the late 90s that would identify the core (super small, usually what you see as "fiber" is the cladding around the core), position them to face each other, warn if the cleave wasn't parallel, arc weld it together, detect any bubbles or imperfections in the weld and alert.

Decent video of the splice process on the splicer I used to use (though missing fiber prep): https://www.youtube.com/watch?v=z4eRhF2oaqA

Crimp tools from brand name vendors are wildly overpriced. You can get a mechanical splice kit for very little money from one of the online fiber stores.

In fact, for less than a grand you can get a brand new core alignment fusion splicer.

A mechanical splice isn’t $10, it’s more like $1 in bulk.

As for consumables, fusion splicers also need new electrodes and calibration from time to time, but these are minor expenses.

Nope, a human with or without a microscope isn’t going to do it better than a fully automated fusion splicer.

I don't think people people should even bother with splicing in under 1km fibre runs if mechanical gel splice is 1000 times faster.

A bigger issue for single mode on short runs if ensuring transmitters are not too powerful. This is why you often have to intentionally attenuate single mode runs.

Solid glass has better mechanical characteristics than mechanical splices and a longer service lifetime.

No short haul optics need attenuators.

Yep, I just learned that modern standard 10G-LR does not need attenuators even for really short runs.

It's actually rather difficult to break cladded G.657 fiber, and it's much cheaper than copper. Now, at the splice point where you must strip the cladding you are correct it is very fragile. At that point you heat shrink on a splint with a steel rod in it which protects it (and typically place that in a splice case).

For sure, if copper works, it’s more practical and slightly cheaper for most situations :)

Regarding the connectors, check out https://www.fs.com/de-en/products/35165.html for details. In particular, they come with a pre-installed and polished fiber, that then only needs to be matched to your fiber using an already-installed matching gel.

It seems like a pretty well thought-out system to me thus far.

FS is one of my favorite websites for design, service, and quality of product. I prefer a cheap fusion splicer ($1500) as I find they work as well as a Sumimoto ($15k), but for one off home projects a mechanical splice with a FS pigtail works great. A 10km SFP ran in home (what, 1km tops?) can handle a fair amount of db loss.

Exactly! For my 10 meter run, it’s easy to make things work, even when they look like they shouldn’t: https://twitter.com/zekjur/status/1286570347337330689/photo/...

Haha that picture both hurts and seems normal. I've buried a splice in a Frozen themed tupperware that's still going 4 years later. Take that $120 underground splice closures.

Fusion splicers haven’t used microscopes for at least twenty years. In fact, I bet it was far longer ago than that.

Are you sure it was a microscope or are you really old skool?

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