Alt-BEAM Archive
Message #11973
To: beam@sgiblab.sgi.com
From: Zane Bryan zipndani@transport.com
Date: Thu, 16 Mar 2000 16:57:39 -0500
Subject: Re: mini motors
>
>
> This is something I've wondered about - how do you go about getting old
> camera lenses? Where do you go? Who do you ask? Are there camera repair
> shops? (I'm not exactly up on the photography scene :-)...
> ...Regarding the lego chain, if you're looking to go smaller, I'm
surprised
> you're looking at Tamiya 4x4 parts, as they seem much larger. Using the
> smallest lego gearwheels and track, you could make a caterpillar track
> (viewed side on) about 9mm total height, 20mm length, which is pretty
> small. Admittedly, the tracks work better on the next gearsize up
> (remembering my lego childhood :), but it's still smaller than the
> footprint of most miniature solar panels. I'm not advocating lego here,
> I'm elaborating as I suspect I've misunderstood something. Not that it
> really matters. :-)
> =====================================================================
>
> Justin,
>
> Typically, I get old cameras from one of the local mom&pop shops here in
> town (Longview, WA)...Sure, they send their disposable cameras to the
> recycler, but the point-n-shoot type are saved out for me. When folks
find
> it costs more to repair an older camera than to buy a new one, or the
> manufacturer doesn't make the parts anymore (designed obsolescence) they
> used to give them back to the customer to dispose of...or the customer
would
> say, "Keep it...I can't do anything with it." Most of what I get are a
> two-motor camera...A larger for winding film (-1/2"x+1" or so) and the
other
> (for focusing the lens) is about 1/2"L x 3/8"H x 7/16"W...pretty small,
with
> a gearhead. I'd just ask around at locally owned places and avoid the big
> name suppliers...The bigger they are the stingier they are. Some places
> develope film and offer limited "send out" repair services...being less
> specialized, they might be you best bet.
>
> As for Tamiya, I'm actually more interested in the rollers on the bumper
> assemblies than the actual gears. At around 1 cm, I think they might
work.
> I'm using a pully-style tread system, rather than geared (although, the
tiny
> lego tread is sounding better all the time). The belt/pully style tread
> (rubber belts instead of chain) cuts the width down just a bit. And the
> cost, since I'm using plumbing seals as belts, is minimal ($.15 ea.
fifteen
> cents!!!)
>
> I see your point about the gears-for-wheels idea...I hooked up a basic
frame
> with motors & gears as wheels...not so efficient. It worked okay on the
> floor until it tangled in a dust-bunny and seized up. Thanx for saving me
> the headache later.
>
> Since I read about someone (you?) attempting the two-sided bot, I've been
> intrigued, but don't have the know-how...mercury switches and such are
going
> to have to wait until I've built a few basics first...I tried tackeling
the
> idea once and discovered that my design was flawed in that if it were
> up-side-down it would become photophobic. I thought about a "tumbler"
> switch to to activate a kick-arm (turbot style) to right the bot, but
> couldn't get past the idea of a third motor...It got complicated...to say
> the least. A simple gravity switch based loosely on the tactile sensor
> design might still be a good idea...I haven't thought it all the way
through
> though.
>
> What I've come up with is pretty much a bot with a low center of gravity
and
> a roll-bar...(design pending), but I've been looking at a lot of roll-over
> toys. Ah, well...back to the drawing board.
>
> Z
>
>
>
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