General welding questions that dont fit in TIG, MIG, Stick, or Certification etc.
Rustyr0d
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    Sat Jul 31, 2021 9:24 pm

I've got a new Lincoln Electric K3419-1 and an offical Lincoln cheater lens I bought which measures 2" x 4.25". It's possible I'm completely missing something, but I can't get the cheater lens to fit! There's some kind of plain plexiglass lens on the inside that came with it, but it measures 1 7/8" x 3 3/4". There's sticker inside the helmet that lists the part numbers for different lenses for the helmet, but if you look them up they're all 2" x 4.25" which is too big! It doesn't fit in the cutout where I assume it's supposed to go (where that smaller plain lens comes out).

The part numbers listed in the helmet are: KH637 (1.5x mag), KH638 (2.0x mag), KH407(2.5x mag).

Pic shows cheater lens where it should go, but the wire will not fit over it and clamp.

Image

Image
hey_allen
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cheater lens snip.jpg
cheater lens snip.jpg (47.9 KiB) Viewed 5017 times
I don't have that helmet, but could it work to slip the lens on top of the wire, only under the circled corners, and lock it down by the wire catching the lens sides with the bends in the wire?
-Josh
Greasy fingered tinkerer.
Rustyr0d
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    Sat Jul 31, 2021 9:24 pm

Thanks for taking a look. It's not ideal but it works. The lens slides around a bit while trying to get the wire over the tabs. The lens is so thick it takes a little effort to get the wire down under the tabs. I think it's just a really bad design. When I get a chance I'll cut some grooves in the edges of the lens with my CNC for the wire to fit into and reduce the thickness.

The next problem is when I flip the helmet up I still need to put my glasses on to see. So even though the cheater lens seems like a good idea it just makes it a hassle to switch back and forth to my glasses.

Thanks for replying!
martinr
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    Thu Dec 23, 2010 3:45 pm
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I don’t like those plexiglass cheater lenses. I use optical, glass cheater lenses in my helmets. My method of fixing is to bond, using epoxy resin, a 3” length of 3mm mild steel filler to each side of the filter lens unit retaining piece, and also bond 4 round neodymium magnets (2 or 3 mm thick) to the corners of the cheater, also using epoxy resin. I have a selection of about 4 or 5 different strength lenses, depending on the distance away I want to hold my head, and swapping lenses over is easy, and they stay in place. I’ll try and upload some photos; it might help give someone ideas in the future.

Edit: some photos. SORRY - having big problems getting them in the right place, but I’m sure the message will get across.

The neodymium magnets are so strong that they will force each other off as the epoxy cures, so I wrap a mild steel plate in paper tissue, which holds the magnets in place and flat, with the lens placed on the magnets. I abrade the plastic to make a mechanical key for the epoxy to bite.

Here I have attached twin lengths of filler wire either side of the inner lens
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Here is a selection of my cheater lenses



The larger lens is a Best Welds lens; the 2 pale blue lenses are Optivisor lenses
97C397A3-B3BD-4D23-9644-979987C73C1E.jpeg
97C397A3-B3BD-4D23-9644-979987C73C1E.jpeg (510.69 KiB) Viewed 4740 times
Attachments
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086ADF55-DD39-4CAB-AB50-47C5135AF6AD.jpeg (2.99 MiB) Viewed 4740 times
Poland308
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There’s always the option of wearing glasses under the hood.
I have more questions than answers

Josh
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