Does the zoetrope spin easily when all is connected?
(such as trying to wind up the weight?)
when you had said it will break a chain before it spins..
It actually sounds like you have a gear locking up
(incorrect mating of the gear teeth maybe?)
(or not enough clearance for easy motion?)
Just a thought.
} > > Hello group,
} > > I am in need of assistance. I have been pushing a deadline for a show
} > > but
} > > now I don't think I will make it.
} > > I am a professional sculptor who prefers kinetic artwork. This
} > > particular
} > > piece was inspired by "The Time Machine" by H. G. Wells. Now my degrees
} > > are
} > > in Art, not engineering...thus the problem I am having.
} > > Essentially, I want to spin an object using a weight driven clock
} > > movement.
} > > About 30 RPM would be great but anywhere around that would suffice. I
} > > have
} > > removed all escapement components from the movement, along with the
} > > gears, leaving only the main drive gears. I have attached one of a
} > > matching
} > > set of bevel gears to the escapement wheel with the mating gear attached
} > > to
} > > the turntable. To better illustrate all this I uploaded a special page
} > > to
} > > my website with pics and drawings. This page can be accessed here:
} > > www.macs.studio.web1000.com/temp_page.htm
} > > As I explain on the web page, I was hoping that the zoetrope would act
} > > a
} > > sort of flywheel and that the weight driven movement would only be
} > > required
} > > to "maintain" the horizontal rotation of the zoetrope. I was sure that
} > > if
} > > enough weight/pull were applied to the mechanism, the friction would be
} > > overcome. I have applied enough weight to actually open up the links in
} > > the
} > > chain and still the rotation is not maintained. The gear ratio from the
} > > weight-driven gear (again, this is all on the web page) to the turntable
} > > is
} > > something like 1 : 4000 so I know that leverage (or a manifestation
} > > there-of) is the problem.
} > > I'm thinking I may have to completely re-think the drive mechanism. I
} > > should mention that, in the interest of integrity, this sculpture needs
} > > to
} > > be driven by a clock movement, not motorized or any such thing.
} > > If I bring my gear ratio down by a factor of 2 or 4, would this help? I
} > > would like the turntable/zoetrope to turn for 12 or more hours before
} > > needing rewinding but I may not be able to reach that. If I bring the
} > > gear
} > > ratio down by a factor of two and employ a pulley system, I can get back
} > > my
} > > duration.
} > > Thanks for your time and let me know if you have any suggestions. If
} > > prefer to email me, remove "whatapain" from my address. Otherwise,
} > > simply
} > > post.
} > I'd look at the bearings, bearing "race", and bearing plate (the
} > turntable). Take a look at a lazy-susan for details. Is the plate
} > "housing" the bearings (at the same level as the centerline) free to
} > as the bearings roll? Are the upper an lower plates metal, so that the
} > bearings don't "embed"?
} > If you remove the turntable, does the clockwork mechanism operate to allow
} > the weight to fall?
} > I would concern myself with the bearings that end up supporting the
} > weights. The first driven shaft will be under tremendous strain.
} > Thats my first pass. Hopefully others will have other good ideas.
} > David A. Smith