What is it? LXI

[R.H.]

Just posted another set:

Rob

[Jon Haugsand]

• R. H.

345 Stop watch with scales for speed measurement.

346 Tool for making square holes 347 Valve handle 348 Kitchen machine (mix master) chunk (or whatever) 349 Funny magnetic experiment. However, I cannot see that there is really a spool. Might be some sort of magnetic cannon. 350 Your son's mischief tool. Needs a leather patch, a rubber string and ammunition. (What is this called in English.)

[giovani]

350. Aha! Methinks you may have it :-) Perhaps a part of a shanghai, ging, slingshot, catapult or whatever name it may carry around the world. The rubber and shot pouch are attached to the holes in the two arms.

[Lloyd E. Sponenburgh]

345. I think it's part of a planimeter.

346. A power mortising chisel (lacking the drill bit)

348. Drill chuck key.

349. Electric motor -- only one side of the insulation is stripped on the "axles" of the coil.

[Tim Shoppa]

I think the watchmaker's term is "tachymetre". An old Omega catalog I have says that it is a shortened version of (get this) "tacho-productometer" ! I personally believe this to be a reverse-acronymics example, the original term makes perfect sense in French.

Tim.

[DoN. Nichols]

Bingo! Very Russian. Acquired from an eBay auction a few years ago.

Enjoy, DoN.

[Jon Haugsand]

• Sal D'Ambra

What is /really/ puzzling with this picture is why the battery isn't rolling over.

[R.H.]

Don's guess is correct, the coil is made from varnish coated magnet wire, each of the two axles has had half of this insulating varnish scraped off, making them function as primitive commutators. I tried Carl's idea of scraping off all of the varnish and got the same results he did, it still worked.

If anybody wants to make one, it works best with very thin wire.

Rob

[R.H.]

I should probably make a puzzle out of it, but I'll go ahead and answer it, I put two small wires on either side to keep it upright. Not much gets by this crew, I didn't expect to have to anwer this question.

Rob

[Jon Haugsand]

• R. H.

Amazing! This /is/ something to impress today's kids with, because they are used to that you have to buy things from the computer store or whatever. But here you can pretend to just find some wire, a used battery and so on. Need to try this. The wire is something I don't have in-house, so I'll need to figure out which store stocks such items.

[DoN. Nichols]

[ ... ]

If you have an old (and preferably dead) wall wart (the oversized lump on the end of power cords for lots of portable things which plugs directly into the wall), they normally have a small power transformer inside. You can recover a lot of wire from one of those -- in two gauges. The finer wire would be wound closer to the center, and connected to the power line, while the slightly coarser wire (probably better for this task) is wound on the outside to produce a low-voltage secondary to power the device -- whatever is is.

Enjoy, DoN.

[R.H.]

I forgot to mention that it works best if you use a very strong rare earth magnet, and for the coil wrap the wire around a C battery ten times.

Rob

[Norman D. Crow]

Grandsons had a ball with stuff like this when I got them an electric hobby kit from Radio Shack a few years back. Lots of neat learning stuff, including simple motor similar to this.

[Jon Haugsand]

• Norman D. Crow

The problem with such kits is that it is "bought magic" and impressive as it may be, it does not make the kids wonder after the show. If you just find a few items around the house and put them together, it may very well make the kids feel that the workings of todays environment is within their own grasp. (Or whatever it should be described.)

[Norman D. Crow]

[Rich Grise]

In the US, Radio Shack. They sell a pack of 3 sizes on small spools. It's called "magnet wire", just in case nobody's mentioned that yet.

Cheers! Rich

[bamboo]

You can pull a few rare earth magnets from most junk hard drives. Probably scrounge the wire too.

[R.H.]

278-1345

That's what I used for the coil wire, the heaviest gauge wire that came in the pack didn't work for some reason, but the next size worked great.

Rob

[Tim Mullen]

Depends on how pre-packaged the kit is. I'm an electrical engineer, and when I was young my dad bought me one of the electronic kits with a couple of transistors, resistors, and capacitors, complete with a peg-board affair where you could assemble circuits with a type of Fahnestock clip.

I had a blast with this kit, and the components later became my first parts stash. :) However, there was a contemporary kit where the components were enclosed in lucite cubes with metal ends and a schematic on top. The idea was to build circuits by joining the cubes together. Somehow this kit struck me as just Not Right. I don't think it would have held my interest as long not being able to handle the actual components themselves.

I also had one of those little motor kits where you wound your own armature. I have to say I think this home-made battery bazinga tops that. :)

Certainly not for the very young, but a great book for kitchen table experiments is the collection(s) of Amateur Scientist articles from Scientific American magazine. One of these articles got me building Van de Graafs as a kid.