Re: Ballscrews/linear drive

No, because this will be two doors pressed together in the center.
How
would I tilt the doors? And worst case, in smoke and fire I want this
to be intuitive to open. Too bad, as Acme screws are much cheaper
than
ballscrews. I had thought about this, too, even considered having a
lever that you'd lift to tilt the nut.

Steve

--- In CAD_CAM_EDM_DRO@egroups.com, "Smoke" <gordonr@r...> wrote:
> Ah...but you CAN use an acme screw. If you suspend the door from a
split
> nut similar to those quick adjustment nuts used on wood vises (and
some
> machine fixturs), all you'd need to do it tilt the door to move it
along the
> screw.
>
> Smoke
> -----Original Message-----
> From: Steve Greenfield <polymorph@p...>

> >I know this isn't directly connected with the primary purpose of
this
> >group, but I don't know where else to ask this:
> >
> >I have been commissioned to build an automatic sliding door. It is
a
> >very custom design, that is why the client isn't just buying a
standard
> >off the shelf door.
> >
> >I'm figuring using a Ballscrew would fit the requirements, with
direct
> >drive from a servomotor. I can't use an Acme thread as I want to
have
> >the option of being able to force the door open if power goes out.
> >
> >I don't care if the ballscrew and nut are used and aren't accurate
or if
> >they have lots of backlash. As long as they aren't so worn as to
cause
> >problems like sticking.
> >
> >I need two of them, this will be a two piece door. Does anyone
here
have
> >used ballscrews/nuts fitting this description, or know where I
might
> >look for this? Trying to save a bit of cash without compromising
the
> >integrity, obviously this isn't a need for high accuracy.
> >
> >The other option I'm considering is something I found in the Small
Parts
> >Inc. catalog. I can't locate my catalog to get the name of it, but
it
> >sort of "climbs" a smooth rod as though it were a ballscrew.
Anyone
know
> >what I'm talking about?
> >
> >Any help is appreciated. Especially names of suppliers in the
> >Tacoma/Seattle area, places that don't have a "3 question limit".
:')
> >
> >Thanks,
> >Steve Greenfield