
Dense white foam pad, self-adhesive on the back, for manly protection against all sorts of masculine bumps. 4-1/2" x 3-1/2" x 3/16" thick, but cut it to whatever size you need. Line your football helmet, cover your knuckles before a bar brawl, clinch it between your teeth for surgery without anesthesia, or keep furniture from scratching the floor (wimp).
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28561 WHITE FOAM PAD |
Okay, polarizing filters for the literal minded. Each filter is a 20 mm dia x 2 mm think piece of glass with a couple of tiny slots in the edge. Each has 20% transmission by itself, which may not sound like much, but is about what you get through decent sunglasses. We are selling a pair so you can do experiments on transmission as you rotate one against the other to reduce the light getting through virtually to nothing. Or you can make some very cool granny sun glasses if that turns you on. The big guys get upwards of $7.00 per filter for these dudes!! Isn't surplus cool??
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26970 POLARIZING FILTERS |
Al Luebbers, our founder, collected glass. Not glass like you'd find on a knick-knack shelf, but optical glass. Lenses, prisms, reticles and filters, for example. Focus on the filters. Many of his filters came out of military surplus, and this is for-real stuff. We mean many are solid dyed optical glass, ground and polished to flatness standards that were probably excessive. Others are from the old days in photographic optics, and their standards were even tighter than your militaristic Uncle's. We've found that photographers, artists, and optical designers still have an occasional need for good glass filters, so we're making a list of some goodies. As always, don't be timid about calling for quotes on quantities. If we have 'em, we'll sell 'em. Just don't sell them back. Please!
| DIAM.or SIZE (mm) | CENTER THICK (mm) | |||
|---|---|---|---|---|
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3477 FILTER, AMBER | 26 | 1.5 | |
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3492 FILTER, AMBER | 30 | 2.3 | |
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3480 FILTER, NEUTRAL | 26 | 1.5 | |
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3490 FILTER, NEUTRAL | 30 | 2.3 | |
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3510 FILTER, NEUTRAL | 50x54 | 3.1 | |
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3512 FILTER, NEUTRAL | 67x70 | 4.1 | |
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3458 FILTER, RED | 6 | 1.4 | |
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3464 FILTER, TYPE A | 9 | 1.8 | |
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3470 FILTER, YELLOW | 18x18 | 1.6 |
We have obtained a large number of real natural corks, mostly surplus with a few fill-ins bought commercially. They range across the popular sizes used in science labs to seal vessels (drill your own holes for glass tubing, etc) and to use as floats. Or just use them to seal bottles that don't have closures or cry out for a decorative seal.
| Top Dia. | Bottom Dia. | ||||
|---|---|---|---|---|---|
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92688P25 CORK #0 | 3/8" | 9/32" | Details | |
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88746 CORK, #00 | 5/16" | 7/32" | Details | |
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92718 CORK, #1 | 7/16" | 5/16" | Details | |
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89230 CORK, #10 | 1" | 3/4" | Details | |
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89232 CORK, #16 | 1-3/8" | 1-1/16" | Details | |
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1711 CORK, #2 | 1/2" | 7/16 | Details | |
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89234 CORK, #20 | 1-5/8 | 1-5/16" | Details | |
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88748 CORK, #3 | 9/16" | 7/16" | Details | |
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23594 CORK, #5 | 11/16" | 9/16" | Details |
Optical imaging folk insist that their reflective surfaces be on top of the glass, because an optically minor “ghost” is created with back surface mirrors. These “First Surface” optical mirrors generally also have better glass and flatter surfaces than their household brethren. Delicate, with the fragile reflective surface exposed, they carry the prices that precision demands. If you are playing with lasers, photography or optical alignment, the first surface items below are what you need. Dimensions are included in the description as width x length x thickness, all in mm.
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69134 MIRROR, FS, 1.5 X 1.5 X 1 | |
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4112 MIRROR, FS, 77 X 194 X 3 | |
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68677 MIRROR, FS, 79 X 140 X 2.8 |
You can start with our single aluminum tuning fork, 2-tined and 7-1/2" long. It vibrates at 256 hz, and is labeled "C". Or you can order the set that has (8) forks and a mallet with a rubber-tipped plastic head. The forks are labeled low-C to high-C and come in a fitted, latched wooden box. Unfortunately, C.J., who has perfect pitch, tells us that his pitch is more perfect than most of the tuning forks. He also says you can file the tips, tuning them to an electronic keyboard until they're perfect - and we think there's a certain cachet to telling people you tuned the forks yourself. But they are perfect, if you're using them for things like teaching principles of sound or driving the chihuahua crazy.
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91185 TUNING FORK | |
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91772 TUNING FORKS, SET |
That's what you get with this tesla coil!! Brand new, commercial item, great for classroom demonstrations and experiments. The 50,000 volt capacity generator radiates high frequency energy through space... enough to light fluorescent tubes two feet away. It uses 115 VAC (60 Hz) with an electro-magnetically operated interrupter buzzer, high voltage capacitors, inductive coil transformer, and a monopolar high frequency transformer generator to do the trick. 11" high, with a 6" sq. x 2" high protective housing for the generator. Includes accessories and instruction booklet with 19 experiments. Pretty amazing. But please, this is not a toy and should be used only under adult supervision.
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70301 TESLA COIL |
Whether you're a beginner or an experienced stargazer, with or without a telescope, you'll get more out of the night sky with a Miller Planisphere. This 10" rotating double disc is a map of the planets, stars and constellations, useful across a large range of the northern latitudes, although most accurate in the range of 35° to 45° north. It can be aligned to the time and date in your location to display a detailed map, and includes tips on finding the planets, suggestions for telescope projects, and more. It's an invaluable learning tool that makes stargazing a lot more fun.
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91720 PLANISPHERE |
This (10) piece set of weights are brass cylinders topped with knobs. The weights are stamped on the top. There are (2) each of 1, 2, 5 and 10 grams, plus (1) 20 and (1) 50 gram weight. If you don't want to display them, they can be stored in their molded plastic holder. Our each is the full set.
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90070 BRASS WEIGHTS |
Well, the next best thing, anyway. 200,000 volts of electrostatic energy created by the Van de Graaf generator you assemble from the kit. Assembly is easy, you need a screwdriver, pliers and scissors - no soldering. A newspaper-like set of instructions includes lots of fun experiments. For grade 6 and up. This is not a toy and should be used under adult supervision. A great tool for teaching about electricity.
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91469 VAN DE GRAFF GEN KIT |
This nice handful of plastic lenses is just the ticket for a primary-school teacher who needs unbreakable samples, and who wouldn't mind having a few interesting pieces left for craft projects. Each DCX lens is 20mm dia, 34.5mm focal length. Not individually wrapped, so a few may have small surface scratches.
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68093 PLASTIC LENS |
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