Building a working test model
In exploring the solar system with propellers
I present a “tongue in cheek” description of a closed system mechanism that can
create propulsion without expelling mass (reactionless propulsion), here I
present instructions for anybody to construct a working model.
I understand that you do not want to spend time and money building
something you are convinced (according to your acquired knowledge) will not
work, therefore the enclosed instructions will permit you to build the model
(that WILL WORK) with little expense.
You will need:
A LEGO MINDSTORM rcx brick.
Assorted LEGO parts.
Epoxy Putty.
You don’t even have to build the thing yourself, just show this page to
a kid (hopefully with his own MINDSTORM) and he will have it “up and running”
in no time. (IT’S THE TESTING OF THE DEVICE YOU HAVE TO SUPERVISE CAREFULLY to
avoid “false positives”)
I assume the persons building this have a working knowledge of the rcx
programming, if not Email me for instructions
Fig 1
Fig 1 illustrates the main parts.
1- MINDSTORM rcx brick as control.
2- 2 LEGO electric motors.
3- Assorted LEGO parts for structure.
4- 2 Propellers, made with balsa wood positioned on a LEGO gear with
Epoxy Putty.
5- Aluminum base.
Those five elements make up the movable “ram mass structure” that is
position on rollers (aluminum tubes Fig 1-6) on aluminum rails (7).
The movable “ram mass structure” must be as lightweight as possible so
it may move by means of the breeze generated by the propellers.
(1 pair of counter rotating propellers mounted on 1 axis is MUCH more
efficient, but more complex to build. This model will work and is easer to
construct, see footnote)
Fig 2
Fig 2 shows what the finished model will look like, including a “all
involving lightweight airtight enclosure” (Fig 2-E), but first we will examine
the movable “ram mass structure” and its parts.
Fig 3
The “ram mass structure” must be free to move easily in ether direction
supported on its rollers, to the right (in Fig 3) there must be a boundary (Fig
3-11) that the “ram mass structure” will “bump” or collide.
To the left the “ram mass structure” must be able to travel unhindered,
no restrains or boundary.
The LEGO motors are connected to one of rcx’s output ports (Fig 3-9),
invert the connection on one of the motors so they will rotate in opposite
directions for stability.
If you try to use only one powerful propeller the results will be
unsatisfactory because of torque.
How it works.
You activate the rcx with the “ram mass structure” assembly some
The rcx gives 100% to both of the propellers LEGO motors (remember they
rotate in opposite direction), the breeze must be strong enough to propel the
“ram mass structure” towards the boundary (Fig 3-11).
When the “ram mass structure” bumps
into the boundary, a contact switch (fig 3-10), connected to one of the rcx’s
sensor inputs will command the rcx output port to “reverse direction”, blowing
a breeze in the “right” direction pushing the “ram mass structure” in the “LEFT” direction.
NOTE: the touch sensor included in LEGO is NOT ADEQUATE (excessively
stiff), you must construct one with a pair of cooper wires
The “ram mass structure” moves
unhindered in the “LEFT” direction until a LEGO light sensor (Fig 3-12) detects
a color strip (Fig 3-12) that command the rcx output port to “reverse
direction”, blowing a breeze in the “left” direction pushing the “ram mass
structure” in the “RIGHT” direction.
The idea is that the “ram mass structure” moves “RIGHT” until it collides with the spacecraft’s
structures and reverses direction, but moves in the “LEFT” direction for a few
centimeters a reverses course WITH MINIMUM INTERACTION WITH THE SPACECRAFT.
Fig 4, Fig 5, Fig 6 and Fig 7 will explain the cycle.
Fig 4.
As illustrated in Fig 4, when we activate the rcx the LEGO motors are
turned on, creating a breeze in the “LEFT” direction pushing the “ram mass
structure” in the “RIGHT” direction.
Fig 5
The “ram mass structure” moves
towards the “RIGHT” until it collides with the boundary (Fig 3-11) attached to
the spacecraft’s structure (represented by the color purple), transferring
momentum in the “RIGHT” direction.
Simultaneously the contact switch (fig 3-10) will command the rcx to
“reverse direction”, blowing a breeze in the “right” direction.
Fig 6
As the “ram mass structure” is
blowing a breeze in the “RIGHT” direction, it will travel in the “LEFT”
direction.
Fig 7
The “ram mass structure” will
travel unhindered in the “LEFT” direction until the LEGO light sensor (Fig 3-12)
detects the color strip (Fig 3-12) that command the rcx output port to “reverse
direction”, blowing a breeze in the “left” direction revering the “ram mass
structure” course WITH MINIMUM
INTERACTION WITH THE SPACECRAFT. (Purple colored structure.)
TESTING
Friction between the spacecraft (purple assembly) and the test table
(brown colored structure) must be minimal, if not you may easily create a
illusion of propulsion crated by a slip sliding effect (false positive)
A inexpensive method to minimize fiction is the separation of the table
and spacecraft structure by means of SMALL aluminum rails and aluminum tubes.
A better method is to make a “sandwich” of ball bearings between two
glass panels between the table a the spacecraft structure, other methods are
more expensive ant I will not try to burden you with them.
All the structural elements must be as lightweight as possible.
The table MUST BE REALLY LEVEL. (Not as easy as it sounds)
Fig 7
As what we a trying to prove is the possibility of a closed system, we
(well you) must construct a “all involving lightweight airtight enclosure”, I
recommend cellophane. (Fig 7)
Fig 8.
The lightweight airtight enclosure’s “backwards” dimension must be of
sufficient length as to allow the breeze to dissipate, if it is to short the
demonstration will not work.
Well, best of luck, feel free to mail wjeconsultant@gmail.com
Return
to exploring the solar system with propellers
1- You can make a pair
of propellers counter rotate on the same axis without complex gear assembly (not
even that complicated) if you position the motors facing one other. (Fig 9)
2- All illustration show
the propeller connected directly to the motor, but you will need a reduction
gear, depending on the exact size and shape of the propeller.
