Exact match. Not showing close matches.
'[OT] Motor gears and a mechanical demultiplexer'
This is completely OT but I'm planning on using a PIC to control the motor
(excuses excuses ;).
I guess the best way to explain what I'm trying to do is to explain the
application. This is for a HO scale engine shed for model trains. The shed
has 6 pairs of doors and I want to use a single stepper motor (one I have
from an old floppy drive) to open and close all six.
Really all I want is 6 mechanical control arms that have a linear motion of
about 1 cm each. I was thinking of a mechanism with a single motor and
solenoid. With the solenoid activated, the stepper motor can select the 1 ~
6 door to open and close. With the solenoid off, the motor gets engaged to
the doors of the selected shed and opens/closes them.
I'm open to other ideas as well. Would like to keep the motion of the doors
as prototypical as possible. Anyone knows of any mechanical assemblies like
It may be cheaper to a motor per door. I was just looking thru a catalog
that had 5V toy motors for $0.50 each.
>Really all I want is 6 mechanical control arms that have a linear motion of
>about 1 cm each. I was thinking of a mechanism with a single motor and
>solenoid. With the solenoid activated, the stepper motor can select the 1 ~
>6 door to open and close. With the solenoid off, the motor gets engaged to
>the doors of the selected shed and opens/closes them.
Use a model airplane servo. Very easy interface. http://www.fmadirect.com
Andy Kunz - Statistical Research, Inc. - Westfield, New Jersey USA
|I guess the best way to explain what I'm trying to do is to explain the
|application. This is for a HO scale engine shed for model trains. The shed
|has 6 pairs of doors and I want to use a single stepper motor (one I have
|from an old floppy drive) to open and close all six.
For hobby applications, you may be best off using seperate
cheap motors for each door. If you look at some VCR's, etc.
you'll be amazed at how far they go to economize on motors:
my old Samsung VCR (which worked very nicely until it started
having problems with the tape sensor) used one motor to spin
the drum head, and used one motor to:
load/eject the tape cartridge
pull out/retract the tape (wrapping it around the drum)
propel the tape for fast forward/rewind
move all the other wierd little doodads
The trick they use is to have the motor turn in one direction
to select a function and turn in the other direction to actually
do it. Neat stuff.
>From your description of what you're trying to do, that degree
of unification might be excessive but making the thing work with
the stepper plus one solenoid might be quite workable. There are
two approaches I'd suggest:
 Have the motor shaft run past all the doors, and have six
"partial" gears on it, each with teeth on 1/6 of its surface
(staggered). Have the solenoid shift the shaft slightly (al-
ong its axis) to cause those gears to disengage from the
doors. To select and open a door, then, engage the solenoid,
rotate the shaft so the gear segment is lined up for the right
door, then release the solenoid and turn the motor in the des-
 Although this approach might be a bit much for 6 doors (it'd
work better with, say, four) it'd have some advantages: rig up
cams so that as the stepper rotates, the doors open and close
in every possible combination. Make the door linkages a bit
springy, however, and have the solenoid lock all the doors in
their current position. To set the doors to "1, 3, 4 open;
2, 5, 6 closed" you would engage the solenoid, rotate the motor
to that position, and then release the solenoid. Maybe a bit
tricky to build, but you'd be able to operate all six doors at
More... (looser matching)
- Last day of these posts
- In 1998
, 1999 only
- New search...