foot-note:
of the same simple ultra design as the precedent, this Stirling engine, thanks
to its diameter of cylinder a little more important, can turn easily starting
from heat sources moderated such as for example that
of the hand, or that produced by the radiation of a small halogenous lamp,
and of course under the
solar radiation.
__
On the image of
left, one sees it turning enlightened by a halogenous lamp of 50W (12V) to
approximately 60 rpm. For that, the engine is equipped with a solar collector
very rudimentary, made up of a simple aluminium foil thickness 0,6 mm, cut out
with the form and painted in black chechmate.
On the image of
right-hand side, in full sun (55.000 luxes), equipped with the same sensor,
turning with 85 rpm.
Although its
manufacture does not pose particular problems, it asks for all the same a
little more detail than for the preceding model, in particular for all that
relates to geometry (parallelism, perpendicularity, etc). If it acts of your
first realization, I would rather advise you to start with you to make the
hand on the
simplified model.
Description:
plan scale
1
overall
picture
slide and
slide
roll and
piston engines
Materials:
- cylinder: melt sheet aluminium ep 0,8, side rhodoοd ep 0,5
- spacers: cylindrical Ψ 6 in Delrin or similar stem
- deplacor (piston inside the cylinder): piece of flagstone for expanded
polystyrene ceiling (approx. 9 mm thickness), laminated ep 3
- drive roll: packing of film 24 X 36 (translucent)
- membrane of the operating piston: piece of disposable vinyl glove (possibly
thermoformι in half-torus)
- gantry: profiled plastic 10 x10 X 1
- rods, axes, crankshaft: piano wire Ψ 0,8
- stage, slide and slide of adjustment: tube brass Ψ int 2,5
- any other business: screws and bolts, discs, shots glass Ψ ext. env. 2,3 -
Ψ int env. 0,9// adhesive cyanoacrylate, thermal adhesive, adhesive neoprene,
cement silicone
- wheel of inertia: well coloured CD, it is prettier...;o)
Construction
of the principal structure:
1
- on an aluminium foil thickness 0,8 mm, start by tracing the
contour of the higher plate (A). Then trace a
central axis (b), and from there, the axes of the
clamp holes of the spacers (c), the contour of
the drive roll and its cutting in half-moon (d),
and finally the position of the feet of the gantry (e). 2 - using a shear cut out the contour of
the plate, then bore all the holes. The half-moon could be easily cut out with
a cutter saws few mm of Ψ (model making), if not, bore several tangent holes,
which you will open with a small file or a small cylindrical cutter. 3 - in tube brass of Ψ 2,5 mm interior,
cut a piece of 32 mm (f). 4 - with a drop of Cyanoacrylate adhesive
stick at each end a glass shot, which will be selected presenting a set of 0,1
mm maximum compared to the diameter of the piano wire Ψ 0,8 mm. 5 - stick to epoxy the tube
thus prepared in the center of the plate, by checking that it is perfectly
perpendicular. 6 - after having crossed, to 20 mm on the
basis of the top of the stopper, a packing of film 24 X 36 (h),
stick it in place on the plate, either with cement with silicone applied
rather largely, or, which is better, with adhesive cyanoacrylate "Super
Plastic" of Loctite which seems to adhere rather well on polypropylene
(in condition, however, of dulling it with the emery cloth - on its
models, N Vivet uses successfully of the Macaw metal). 7 - cut out the elements of the gantry (e)
in a plastic section of 10 X 10 X 1, and assemble flat with the adhesive
cyanoacrylate. Then a few minutes, when it is sufficiently rigid, to later
stick it in place on the plate with epoxy adhesive, by controlling squaring. 8 - cut a piece of 48 mm in tube brass of
Ψ 2,5 mm interior (i). 9 - with a drop of
Cyanoacrylate adhesive stick at each end a glass shot, selected to present a
set of 0,1 mm maximum compared to the diameter of the piano wire (Ψ 0,8 mm). 10 - stick to the thermal
adhesive the tube thus prepared in the center of the bracket, by checking that
it is well centered, quite horizontal and correctly aligned. 11 - trace then cut out in a sheet of
rhodoοd ep 0,5 mm, a 17 mm broad band by 560 mm length (k).
Connect the two ends with cement silicone by making them overlap of 20 Misters
Laissez to polymerize several hours by maintaining the joint tightened by a
clothes pin;o) 12 - once it solidified joint stick the
band places from there under the plate, using a continuous cement silicone
cord smoothed with the wet finger, or a potato section. 13 - screw on the higher plate
both spacer in Delrin Ψ 6 mm X 17 mm (m).
Manufacture
of the deplacor:
1 - in a piece of flagstone for expanded
polystyrene ceiling 9 mm thickness cut out with a hot wire a disc of Ψ 165 mm
(n) 2 - in plywood ep 3 mm, cut out a disc of
Ψ 40 mm (o). 3 - hollow out the site corresponding in
one of the faces of the polystyrene disc, and in the other, to make a small
cylindrical hollow to leave the place at the end of the guide tube (Ψ 5 mm X
3 mm for example). 4 - stick in place the plywood disc with
epoxy adhesive 5 - hot cut out (for example with the nose
of a thermal glue gun) the two lights (p)
allowing the passage of the spacers, by guiding you on the edge of the plywood
disc.
Manufacture
of the lower plate:
Trace and cut out in
an aluminium foil ep 0,8 mm the head the cylinder (q),
without forgetting the small inspection door (r)
which will enable you to intervene thereafter on the fixing of the slide (and
possibly its replacement)
Manufacture
of the wheel of inertia:
Nothing private individual to be announced, if not that it is necessary to
find or manufacture a plastic (s) part returning
without play in CD (t), and to stick it to the
thermal adhesive. Bore well then a hole of 1 mm in the center, and a second,
to 3,25 mm of the first, intended to receive the axis where will come to cling
the rod of the deplacor.
Manufacture
of the axes, rods and slide:
Nothing private
individual either, if not that these elements are worked starting from piano
wire Ψ 0,8 mm which it will possibly be advisable to rectify, if, like me,
you bought it conditioned in roller.
Manufacture
of the membrane:
Initially, it will be simply cut out in the finest part of a disposable vinyl (u)
glove , and pinch between two discs Ψ 16
mm by a small bolt of Ψ 3 Misters Plus late, if you want to improve a little
the output of your engine, you will be able rather simply to produce a
thermoformιe membrane - to
see FAQ - which will have a little the pace of two concentric half-tori
(see in the following page).
Assembly
of the slide and the deplacor:
(to facilitate
future balancing to you, you can, before assembling them, to weigh the
coulisseau/deplacor unit on a mechanical letter balance, or better digital,
giving the 1/10 of G - note the weight of the unit, and while you are there
weigh also the membrane with its screw and the discs)
Deposit (important)
a fine oil film over the entire length of the slide (v),
except on the last centimetre which is intended to be stuck in the plywood (o)
disc . To introduce the slide into the slide (f)
since outside so that it exceeds approximately 2 cm in the cylinder, then
insert the deplacor on the slide until it comes resting against the bottom.
Move back a little the slide so that it levels the higher face of the deplacor.
Center well the spacers in the center of the lights, and direct the ball of
glass according to the principal axis. When all is aligned, immobilize with
the thermal adhesive, let cool completely and check that the whole moves
freely.
Closing
of the cylinder:
You can now close the cylinder. Screw the lower plate (q)
on the two spacers, then stick it with cement to silicone. Smooth and let
polymerize. (stick the inspection door (r) only
in all last place, when you carry out all the adjustments)
Last
assemblies and adjustments:
1 - stick to the thermal adhesive CD (t)
on its axis, by holding account of the dephasing of 90° between the crank of
the deplacor and that of the operating piston. During cooling, check that CD
runs smoothly. As long as the adhesive is not completely cold, you can still
perfect his alignment. 2 - assemble the rod of the deplacor (w)
and regulate to have 5/10 mm of play at the point died high and the point died
low. Fix it on the axes with a small piece of electric sheath. 3 - grip the membrane (u)
between the hollow lid of limps of film (h) and
the body of the case in order to leave a clearance from 1 to 2 mm higher than
the travel of the crank. To pass the rod engine (x)
on the crank and stick it to the thermal adhesive on the screw (y)
passing in the center of the membrane. Fix the rod with a small piece of
electric sheath. 4 - to stick the inspection door (r)
with adhesive neoprene, in order to be able to dismount it where necessary.
Let dry completely while not touching more with the engine!
Static
balancing:
If you weighed the various elements before assembling them, it is enough for
example to balance the deplacor statically to make the total of all that is
suspended on the axis of the crank, and, by then submitting the report/ratio
of the arms of lever you will calculate the weight easily (and outdistances
it) mass of balancing which will be naturally placed contrary to the axis of
the crank - to
see FAQ -
More simply, the
moment due to the runner of balancing must have the same value, and to be
direction opposed to that due to the weight of the moving element of the
deplacor. For example: if the deplacor + the slide + the rod weigh 10 G, if
the crank has a total clearance of 7 mm, and if one wants to use a runner of 1
G, one will place it at 10 * 3,5/1 = 35 mm of the axis of CD.
And you will not have any more but to make the same thing on the side of the
rod and the operating piston.
ADVISORY: With any
technology, you take a high risk to invest significant time or money
unless (1) independent testing has thoroughly corroborated the
technology, (2) the group involved has intellectual rights to the
technology, and (3) the group has the ability to make a success of
the endeavor.
All
truth passes through three stages:
First, it is ridiculed;
Second, it is violently opposed; and
Third, it is accepted as self-evident.
--
Arthur Schopenhauer (1788-1860)
"When you're one step ahead
of the crowd you're a genius.
When you're two steps ahead,
you're a crackpot."
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