Mike Rambour wrote:
> What I need to figure out is how to make a 90degree turn and turn a
> shaft with some gears. I have a 1/2" shaft coming out of a I-beam that
> goes into a frame about 4 inches, it needs to turn a threaded rod that
> is at 90degrees to that shaft. I have browsed and searched the net for
> hours and hours, I have found some small gears that would do the job but
> they are pot metal and the threaded shaft is going to be supporting
> nearly a 1,000lbs, the shaft actually does not support the weight but it
> will move the weight on casters in a "lipped channel" so the small
> gears I found being pot metal probably would not work. It can even be
> geared to make it easier to move if that can be found.
Get the lower unit of an old outboard motor. They convert a vertical
spinning shaft (from powerhead) to a horizontal one (to propellor). They
also hold their own oil (or grease) and are sealed oiltight on both shafts.
They have some gear reduction as well (about 3:1 depending on the
model), and can be purchased up to handling hundreds of horsepower engines.
...and a big bonus that might help you, they have forward, neutral,
and reverse shiftable on the unit. (a little shaft needs to be turned,
you could weld a little hand on it and make it downright pleasant to use.
So without knowing what you are doing, you could leave your motor
running all the time and use the gearbox to switch the threads spinning
one way, the other way, or not at all, to position your load. Or just
leave it in forwards if you'd rather do that eletrically.
> Next item on the list is the threaded shaft, I was going to use simple
> all-thread but I found references to ACME threads and that sure sounds
> like a Wiley Coyote disaster waiting to happen to me but they are
> supposed to be better, are they ?
Acme threads are designed to be turned under load. Good for things
like jackposts, vices, etc. So if something is going to have to be
turning the thread to move something that is under force, you'll want an
ACME thread.
(basically big flat square threads, look at the shaft of any decent
quality vice or C-clamp or anything really)
If your load rolls back and forth easily you may not need this, but
it would never hurt.
--
Trevor Boicey, P. Eng.
Ottawa, Canada, tboicey@brit.ca
ICQ #17432933 http://www.brit.ca/~tboicey/
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