Losing a lot of spools due to pinching

[Sheldon Dingwall]

We've been losing way too many spools of #42 due to wire getting pinched in the spool. Mostly the conical flanges from Essex, but also straight flange spools from Shelhav.

The breaks are always at the flange. Sometimes we can carefully pull the tail out by hand and continue winding, sometimes that only gets you one traverse across the spool and then breaks again.

The spools are typically shipped upright with no padding underneath.

Any thoughts on how to prevent this problem?

[Joe Gwinn]

We've been losing way too many spools of #42 due to wire getting pinched in the spool. Mostly the conical flanges from Essex, but also straight flange spools from Shelhav.

The breaks are always at the flange. Sometimes we can carefully pull the tail out by hand and continue winding, sometimes that only gets you one traverse across the spool and then breaks again.

The spools are typically shipped upright with no padding underneath.

Any thoughts on how to prevent this problem?

Yeah. This cannot be the first time such a thing has come up. Make it the wire sellers' problem - after all, they decided how and how well to pack it for shipping. Sounds like a defective spool of wire. The defect may have been latent, but is is surely a defect. Nor does it matter if the wire started out defective, or became that way in transit. And while wire sellers should know how to pack wire, they can certainly choose to underpack and replace the spools that don't survive. It's a business tradeoff.

The standard counterargument would be that you somehow mishandled the spools after receipt, so I would be prepared for the question.


War story: In the 1970s I was offered a consulting job by a friend that worked at a trucking company. The problem was that an electronic cabinet had been destroyed in transit when a big heavy transformer came loose and bounced around inside, and the electronics manufacturer that built the cabinet was claiming that the trucking company had mishandled the cabinet, and was seeking compensation. I was unable to accept the commission because of prior commitments, but I gave my friend a list of things to look for, the first thing being how strongly the transformer was mounted.

When I came back from my business trip, I asked how it had gone. It turned out that the transformer and the bracket that it was attached to were held together with a handful of little hardware-store 6-32 self-tapping sheet-metal screws. No wonder the transformer came loose. One good bump and the first screw broke loose and the second bump caused the whole assembly to unzip, releasing the transformer.

Compensation was denied.

[Possum]

...

If it is breaking at one flange put that one at top and maybe you could use a cut off wheel and dremel and cut just inside the core edge and see if you can break the entire flange off, no more flange. If its breaking on both flanges , maybe you could use a heat gun on the plastic and bend it upwards away from the wire. But yeah, complain to the company, I've never had that happen before..

[David Schwab]

sometimes that only gets you one traverse across the spool and then breaks again.

How do you have your spools oriented to the winder?

I've only had one that snagged just recently, and that had an actual loop in the wire.

I sit my spool about three feet lower than the winder, sitting upright, and it de-spools off the top of the flange.

[Sheldon Dingwall]

Those are some good ideas Dave. It's too bad the spools weren't disassemblable.

David, we have the spool on top of the winder. The wire travels up about 2' to a small pulley on a spring loaded arm, then over 1' to the elbow of the arm, over some felt, then down to the traverse guide. Originally we were using a plastic bell over the spool to contain the wire as it spun off the reel, now we're using a wisker disc.

We're winding at 3000 RPM. Our coils are a little shorter than a guitar coil.

[Possum]

...

You might want to try putting it on the floor so there is much more travel space from spool to feed, this will tend to make the wire spin outwards at winding speed and might solve the problem, maybe....

[Zhangliqun]

I've never run into this problem either. I have my spool on a boom stand about 6 feet behind me with the axis of the spool parallel with the travel of the wire toward the bobbin. 4 feet is usually plenty but I obviously like to play it extra safe since the MWS PE spools are not angled or slanted, just plain ol' straight-flange spools...

[David Schwab]

You might want to try putting it on the floor so there is much more travel space from spool to feed, this will tend to make the wire spin outwards at winding speed and might solve the problem, maybe....

That's what I do. It's a lot lower teach that Sheldon's setup, I'm sure.

[Zhangliqun]

Those are some good ideas Dave. It's too bad the spools weren't disassemblable.

David, we have the spool on top of the winder. The wire travels up about 2' to a small pulley on a spring loaded arm, then over 1' to the elbow of the arm, over some felt, then down to the traverse guide. Originally we were using a plastic bell over the spool to contain the wire as it spun off the reel, now we're using a wisker disc.

We're winding at 3000 RPM. Our coils are a little shorter than a guitar coil.

You need at least 4 feet in a straight line with no pulleys or other gadgets to restrict the swing of the wire. The pulley and elbow are very likely preventing the wire from swinging wide enough around the spool flange to avoid breakage.

[David King]

I've been thinking about this too and I wonder if there's something causing tugging on the wire (like that spring pulley set up) that pulls the wire down into the gap at the edge of the spool. Winding at 3K might just be a part of the problem?

[Bruce Johnson]

Sheldon;

Another approach would be to add a larger diameter disk on to the front flange of the spool. For example, if your spools are 6" dia, make up a 10" dia disk of 1/4" aluminum, with a pilot that plugs into the hole in the spool. Put a gentle radius on the outer edge and polish it to a mirror gloss.

This would do two things: First, because of the larger diameter, it would pull the wire up straighter from the spool (that is, closer to perpendicular to the axis), which may help pull it out of the pinched area with less force. Second, it would provide a new, more precise flange, and keep the wire from even contacting the spool's own flange.

[jason lollar]

It happens- I use shitloads of wire so I run across it, the conical spools are the worse. If they get bumped in shipment the wire will shift and fold in on itself. Alot of times it happens as its spooled too. I get spools of wire in we havent even used yet and you can see the wire folding back under itself at the flange. I have probably lost 200 pounds of wire due to that over the years maybe more.
Usually I just send it back but you can save the spool given enough time- I have done this many times and it woirks but you could spend 30 or 40 minutes doing it. Take a sharp knife or razor blade and score straight down the side of the wire from flange to flange- cut in one clean line about maybe 1/4 inch deep then start peeling off wire. Eventually youll get down to three or four strands coming off. If you hang the spool up high from the ceiling the wire will sort of help despool itself, just start pulling down on it into a trash can or box- anyway get down to 3 or 4 strands and the trick is to figure out which one is the end of the spool and which are still wire remnants- you really have to watch what wire is crossing under which one and pay attention and eventually youll get to the one wire.

[David King]

Fun! seems like a good job for a pack of bored, adolescent kittens.

[Sheldon Dingwall]

Thanks for the input guys. I suspect it's not a feeding issue because when we're left with a little tail of wire coming off the spool, you really have to tug on it to pull it free from the pinched spot. In many cases it will break as you're doing this and then you're toast.

Jason, do you ever get your spools shipped on their sides? We're trying this with our current order. I'm going to request extra padding on the bottom of the box too.

Did you hear the news about Shelhav?

[jason lollar]

yeah I have been around and around about shipping- its got to be packed right when they ship 40 pounds in one box.
At one point I was considering making a re-useable packing crate.
If the box gets dropped- believe me I have had boxes show up almost destroyed because the the smallish size and heavy content or its packaged with the weight off center- once its dropped it increases the chance of pinching.
Yeah shelhave is out- heard about that, we are working on getting someone to make the same range of diameter wire.