Cables

I've heard of crazier things. Henry Ford would weigh a stack of invoices and a stack of sales orders to get an approximation of what the cash flow was.

:-) assuming that an invoice is the same weight as a sales order. Who would argue with Henry Ford?

I use a set of accurate Post Office quality scales daily to estimate quantities of various parts and ICs.

In the case of very small items such as ICs, I would need to count say 10 or 100 at a time.

How about you try different manufacturers over the same length. Of course the RJ-45 fittings should weight pretty much the same, so if you can determine the manufacturer, make up a table for different lengths, and manufacturers. Pretty soon, I feel you will have the data to throw an unknown cable on the scales, and determine the correct length.

Good luck with it.

Cheers Don...

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Bare Proto PCB for PIC or AVR projects?
"I'd buy that for a Dollar!".

You want label-ties. They are a small cable tie with a 5mm x 18mm tab integrated which you can write the cable ID on.

Like this:

I get mine from a local general electronics components supplier, only a few cents each in a bag of 100. They are also good for labelling installed cables so you knwo where they go / come from etc.

Ah, OK. It looks like it is a "tie wrap" ("nylon" thingie with a ratchet built into one end so that once tightened it can't be loosened) with a plastic tag?

But, doesn't the presence of that tag limit just how small a diameter cable it will "cinch" onto? (since the tag must be less than the circumference)

If these are made of that same nylon-ish material, then I don't imagine they will tear easily (though might snag other cables in the "run")?

Yes, but installed cables tend to be pretty passive. So, adding a label *after* the cable is installed has no real consequences (towards pulling the cable, etc) I'm concerned that having these on the cables before installation could pose a problem running them (?)

But, for a few bucks, it's worth the attempt! Since I will have to uncoil, measure and re-coil each cable to label them this way, I may also "take some data" regarding cable weights to see how that fares, too. I suspect I can find a cheap postal scale that will measure tenths of ounces, for example.

Thanks!

--don

I just measured one with my verniers;

Tag is 25 wide x 8 tall, the tie is 2.5mm wide x 100mm long. They zip up well and dont slip on the 5.5mm diameter ethernet cable that I use.

They are tough - you wont tear them or break them easily, you need to cut them off, they cant be pulled off by hand. They dont really snag other cables any more than the RJ45 connector on the end of the cable does. I reckon they are great (I don't have shares in the company that makes them, I'm just a happy consumer!)

OK, so the "tag" is reasonably flexible, then (i.e., imagine if it was NOT -- the tie wrap would never "cinch" tight).

Yeah, the connectors are already a problem for me. Anything without a boot is short-lived here. No cable trays to run things in... just a wad of assorted cabling along the baseboard around the perimeter of the room! (I think there is close to 1000 ft of cabling in that tiny room -- when you consider CAT5, power cords, SCSI, serial, USB, etc. cables)

I already started looking for them and stumbled on this:

The rightmost would obviously be a bad choice for small diameter cables. The center would be a bad choice as the "tag" would stick up/out and be sure to snag on *something*. The leftmost seems to be similar to what you have described.

I'll have to call around some local shops to see if anyone has some in stock.

Thanks!

--don

Actually, I have been surprised at how many "tricks" like this actually *work*! At a summer job whilst in college, my boss/mentor handed me an internal technical report describing some very unusual ways of doing shirt-sleeve statistical analysis of process quality. The sorts of things a shop foreman could do without formal education. I remember being amazed at the "magic" behind it! Never took the time to figure out *why* it worked but surely there must be some science behind it (e.g., like Trachtenberg's "magic")

I wonder if I have that memo anyplace in my "pile"...

Yeah, a lot of scales have a "count" option with which you set a "known" quantity and it then tells you the current quantity as a multiple of this.

I wasn't going to even bother trying to identify manufacturers. I suspect for what I call "short" cables (< 25 ft?) I can probably get a length estimate good to a foot or so. Note that apart from "homemade"/handmade cables, I suspect store bought cables are sold in certain preset lengths (dunno... I've never had to buy one :> ). So, I imagine I can just come up with some ranges and use them to categorize cables into these preset lengths (?)

I'll have to weigh one of the longer cables to get an idea as to maximum weight before I go looking for scales.

[estimating CAT5 cable length]

Not sure how accurate those network analyzers are, but they can estimate cable length. If you want more accuracy, make sockets to put the 4 pairs in series en measure the propagation time of that. Maybe with a standard analyzer, or just use a pulse generator and a scope.

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Stef    (remove caps, dashes and .invalid from e-mail address to reply by mail)

You'll feel much better once you've given up hope.

One item that sits on my desk and is permanently connected to the PC is a Kroy label printer. This is capable of indelibly printing heat-shrink sleeving and wrap-around labels. Each cable, as it is made up, gets a unique identifier, type number and the length of the cable printed on it (one label for each end). This works very well and I haven't lost any cable ident in 12 years of using the system.

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consider some permanent colored markers/paint and using the color code.

I assume you could discern an order of magnitude such that there would be no confusion between Orange meaning 3 feet or 30 feet hah!

-----------------------------------------------^^^^^^^^^^^^^^^^^

Yes, I have a K2000. Looks a lot like this newer version:

I used this to label the CAT5 I ran throughout the house. (eats batteries, though, so it's almost essential to use it on AC adapter!)

But, I found the shrink-wrap labels only worked well on "hand-made" cables -- i.e., those where I could slip the unshrunk tubing onto the wire *before* attaching the connector body. On "pre-made" cables, it seemed like the tubing size necessary to fit *over* the connector was so large that shrinking it down to adhere to the cable diameter was a problem.

I like the "label ties" solution as it should work with even nastier cables -- those in which the ratio of connector size to cable diameter is even greater -- like power cords, wide SCSI, etc. And, they appear to be orders of magnitude less expensive than equivalent lengths of Kroy tubing!! :< I'll try to make time to locate a supplier today.

--don

Ooo, Ooo! I've got a cable tester that has that ability! As you said, no idea how accurate it is. :< Let me drag it out and see what it says for some of the "known" cables that I have in use...

(sigh) I need a place where I can arrange all my "toys" so they are VISIBLE instead of tucked away in little boxes (or, in this case, one of those fake leather carrying cases). I wonder how long it would take to dig a basement under this house?? :-/

Now that's *way* too much work! ;-)

Thanks!!

--don

?? Why are you using the shrink-wrap labels??

Kroy also has self-laminating wire labels. Ie. 1.25" x 1" works well for Cazt5. Print on it, wrap it around, and then it has a clear tail that wraps around again over the printed label surface to protect it. Works very well.

If you just want to keep track of the size when putting them in the box how about gallon zip lock bags? You can write the cable info on the bag and it stacks nicer without the cables getting tangled. Depending on the box maybe put the bags vertical ordered by size. Or even combine labeling and bagging.

I didn't like those. I found that an end would invariably get "lifted" and the adhesive gets "gummy". Then, starts picking up all sorts of cruft (dust, etc.). I would end up having to cut off the affected "tail"... but this would leave a gummy residue on the top-side of the label where it had previously adhered. Mineral spirits would remove this -- but probably contributed to further "lifting" of the now trimmed tail.

It just ended up being too much work to keep the labels from getting ratty. The shrink wrap worked *great* on the cables that I made. No ends to work themselves loose, no sticky residue, etc.

Originally, I was concerned that the "printing" would come off and thought of wrapping *tape* (poor man's laminate) over them. But, it was obvious that this would lead to the same situation that I had been trying to avoid...

That's the same problem that I mentioned in original post re: putting a "tag" on the cable --- once you remove the tag, you lose track of how long the cable is. Granted, you already have the cable "out" (deployed) but that doesn't mean you can easily re-measure it.

For example, several months ago I relocated the switch that services the machines in the office. Of course, *all* of the cables plugged into it are then made too long or too short (depending on how far I displace the switch). Fishing all of the cables out, measuring them (even if just "by eye") and then redeploying them would be a major undertaking -- the cables run along the baseboard, *under* my work tables and *behind* all of the equipment on the floor. I.e., getting to them to extract them (without breaking the tabs off the connectors)

*or* reroute them requires a body considerably more flexible than mine has become :>

It would have been *really* nice to just look at a tag on either end of a cable to figure out where it *could* be used and then just "shift" it's position (tug on one end or the other) into a more appropriate location for the new switch deployment. Instead, I had to "measure by eye" -- "OK, this cable connects that machine to the old switch location. That distance is roughly the same as the distance from *this* machine to the *new* switch location so if I just pull this end over a few feet, the other end should fall into place as well!"

Things were *so* much easier when everything was 10Base2!

That's probably be a good idea! Even colored bands of tape. I suspect a single band would suffice. I.e., (using your example below) a single orange (?) stripe could label a

3 ft or a 30 ft cable. *AND* a 13 ft cable!

I'd have to think this through to see if there are any ambiguous cases. Might see some trouble resolving "23" vs "30" :-/

Past experience with "tape-like" labels leaves me apprehensive, though, as the tail end invariably lifts. I'd also have to keep a bright light when viewing them to avoid misreading colors (and hope they don't fade or discolor over time -- I store most of this sort of stuff in the garage which can be quite hostile)

Another solution is to use resistors color coding and rings of red brown black tape around the cables.

with Henry Ford?

Please format lines at 70 at most.

The you tell the scale "these were 10 or 100 items", and the scale will show numbers, not weights. This kind of scales are available widely.

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Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
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