OT: electric motor brush WTF

51594

Forwarding to the correct newsgroup, since my bike friends have no clue. ;-)

I *guess* it is a safety thing.

The arrangement appears to lift the worn brush off the commutator after things cool off a bit, preventing arcing.

They sure are proud of those parts:

$55.75 US for *each brush*.

--Winston

What are they - gold plated titanium?

PlainBill

Platinum Unobtainium. :)

--Winston

8351594

Actually, they don't actuate until you've worn down the brush about

3/4 worth, then they pop out. Wait, I see what you're saying--they pop out so you have enough contact to conduct current, but not so much that the motor works. As opposed to what will happen now if I manage to wear one out, it will gradually arc. But a small arc, surrounded by insulating material. I'm no engineer, but it seems like overengineering to me. Perhaps some Swedish law. Still not worth $55 per side. (!!!)

to rip you off.

why are they using a brush type motor in the first place?

they're probably just inept, sweden is good at carboard furniture and not letting go of disco, not clever engineering.

Many carbon brushes have wear indicators, but I've never seen anything like the spring disconnect. I once bought a very used 1/2" electric drill with very worn brushes. There wasn't enough spring tension to hold the brushes tightly, so they arced badly. The plastic retainers for the brass sleeves that make electrical connection to the brushes were melted on both sides. If the plastic had melted through, the brass sleeves would have touched the metal motor frame and created a rather nasty shock hazard.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

8351594

Thanks, I'm Swedish. Askos are beloved over here because they're reasonably priced, last at least twenty years, and are incredibly easy to work on. The motors spin at extreme speeds, but it's rare that you have to replace brushes more often than every decade and it takes ten minutes. I was just curious about the brushes themselves, which could have been made anywhere from the EU to Mongolia...

(...)

Well, I admit that I *was* guessing.

Still, it is a 'perspective' thing in a way. Lots of times I would have been thrilled to bring an appliance back to life for only ~$120 plus taxes and shipping.

--Winston

Cydrome Leader wrote in news:j30scc$sj$ snipped-for-privacy@reader1.panix.com:

Yet Sweden has fielded the SAAB/Scania Gripen,Viggen,and Draken jet fighters,all excellent engineering projects,very advanced for their eras.

--
Jim Yanik
jyanik
at
localnet
dot com

the egyptians were good at stuff a long time ago too.

so what's the problem then?

your soviet designed, chain driven appliance with brushes in the motors (was this an upgrade from the steam engine version?) lasts from 10 to 20 years and only takes 10 minutes to fix.

That sounds good to me.

Cydrome Leader wrote in news:j33cut$sm2$ snipped-for-privacy@reader1.panix.com:

JAS 39 Gripen is modern. Good enough that other nations are buying them,IIRC. ISTR that the US is buying some Swedish BOFORS weapons,too.

--
Jim Yanik
jyanik
at
localnet
dot com

yeah, good enough for heavy hitters like the south african and hungarian air force.

Those would be nice to play with.

Cydrome Leader wrote in news:j361na$1m9$ snipped-for-privacy@reader1.panix.com:

yes,considering they are poor nations and still could have bought US or Russian aircraft. Gripen may fit their needs better than US/Russian AC. It's designed to be field-maintainable,and have an ability use public roads for runways.(after [or before] the usual bases are bombed out.) OTOH,most other modern fighters must be maintained at and operated from military bases.

Gripen is still a modern,high performance fighter.

--
Jim Yanik
jyanik
at
localnet
dot com

You really think the auth african air force can afford US made airplanes? I'll give them credit when due though, nobody wants some russian shit either. All russian planes are good for are crashing at airshows.

Maybe they should just get some cessnas, or some retired news helicopters. They'd be more fitting for such primitive places.

Did you just copy and paste this description of this plane from a craiglist or yahoo auctions site, or wherever you'd buy a used kit airplane?

sure it is.

Cydrome Leader wrote in news:j36hdc$ain$ snipped-for-privacy@reader1.panix.com:

Odd,India is buying a bunch of Russian fighters. Of course,THEY have the technology base to maintain them.

Shows what you know. zip.

--
Jim Yanik
jyanik
at
localnet
dot com