Mounting / connecting the control surfaces:
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All of the control surfaces needs
to be connected to servos inside the hull. The two dive planes on the
sail can be directly mechanically linked to the aft dive planes, or
given their own servo with a pitch controller. This would allow them to
follow the aft dive planes when you give the orders, but, when left
alone, the pitch controller would adjust the submarines pitch using
these dive planes alone. In the initial stage, I choose to connect the
sail dive planes directly to the aft planes, and only later retrofit a
pitch controller if needed. Some subs tend to "dolphin swim" (jumpy
style) without a pitch controller, but not all. I'll wait and see what
mine does before adding the pitch controller.
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Here's a perfect view from the
pre-fitting face of the aft dive planes, showing that the fixed part of the dive
plane are
secured with a bolt. The bolt ensures that the control surface can not
brake loose and fall completely of the sub in the event of a collision.
The widest point of the entire sub are the aft dive planes, and they are
pretty exposed by the location as well, so thinking that they won't ever
take a hit, would be wrong. |
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This shows the stand including guide
lines drawn on it. The stand was used to ensure a proper location of the
dive planes, and gave a rather good fix too! The masking tape prevents
resin from spilling on the actual hull when gluing later on.
Note that the hull surface has been filed rough, where the glue needs to
go.
Before gluing: Drill the holes for
the bearings for the moving parts. There will be no space for this
later... |
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Now the fixed part has been glued and bolted on. Using a
cotton pick, I removed the surplus resin around
the structure, leaving an almost complete finish right of. Now the masking tape can come of again. |
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A nice front view of the now glued and bolted control surfaces.
The "middle" of the hull was found by placing a drawing tool in the
exact half height of the entire main hull ( 80 mm ), and then drawing a
line where the center of the dive planes should go on the aft ends
sides. This process involved placing the hull exactly leveled, so the
rudders would be fitted evenly with the zero-balanced hull. (Roll = 0
degrees) |
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Now it needs to be left alone for 16 hours,
allowing the resin to completely cure. The masking tape on the stand
ensures that nothing slowly slides any where. This is one of the most
visible areas on the sub, and any error would be nothing smaller than a disaster. |
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Ensuring that the fix is symmetrical is
important, which this confirms. The small gap between the stand and the
dive plane on the starboard side, is caused by a small deviation in the stand construction, not the rudder
location. |
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This is the port side nylon bearing for
the moving part of the dive planes. The actual shaft is used to hold it
in place until the resin is fully cured. The initial fix of the bearings
was done using superglue, followed by a complete fix in resin. Drilling
this hole for the bearing was done prior to fitting the dive plane, and
only slightly adjusted afterwards with a thin file, before fitting the
bearing. |
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The finished port side result! The
starboard is symmetrical alike, and the process result was a perfect
hit.
When the shafts have been connected internally, and the moving parts of
the dive planes has been fitted, then the vertical stabilizing fin will
go on to the end of the fixed half. The stabilizing fin will
"close" the hole made for the shaft, ensuring that it can not ever fall
out. |
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When it comes to the mechanical link of the aft control planes, there
are one major problem: We have three axis crossing each other in one
point. First, the rudders and dive planes need to operate without being
in each others way at all times, and the propeller shaft needs to go
right through the center line of the sub too. How do we do that? Well,
take a look at this image, which is from another sub builder on the internet.
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By looking at this blue print, and the four small
step-by-step linkage horns, you can get a picture of how the three
shafts that are crossing each other in one point. (And yes, the drawing
is for free...)
The 1st servo horn is the raw one.
The 2nd servo horn has had it's center hole filled with resin. (hole too
big otherwise)
The 3rd servo horn has been cut and shaped.
The 4th servo horn has been
shortened even more, as it's the one on the
far side. (see images below) |
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Here the linkage has been fitted, and
gives a rather good idea of how the control surface controls are linked.
Notice the masking tape on the right servo horn.
It's there only to protect the hole needed for the remaining linkage,
and will be removed once the resin has cured. |
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An out side view of the now linked
dive planes. They ride so easy in their nylon bearings, that the weight
alone pull them down when not supported. This is important to save servo
power consumption, thus battery life. |
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Here the vertical stabilizers has been fitted. The
small nail was filed down, after it had secured the component during
curing. Special care was taken to ensure that the two vertical
stabilizers was completely parallel, and that NO resin had got into the
dive plane shaft bearing at the outer ends... pretty important..
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This is the basic rudder components.
Seen from left to right:
The rudder with the brass shaft mounted, then the small Teflon bearing,
then the black (stationary) bearing that goes into the hull, then the
brass lock, and finally the servo horn. (Last two components not
finished.)
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The rudders are pretty much alike,
except for the light in the top one. This image shows the top one,
exposing the channels for the wires, and the hole in the rudder shaft,
where these wires will later run from the top light, into the hollow
shaft, and down inside the hull.
Notice that the hole is right below the Teflon bearing, which is now
secured within the rudder.
The lower rudder is as mentioned before alike, except for this wire
channel, and that the shaft on the lower rudder has been filled with
resin, giving strength. |
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The two black, fixed bearings was
fitted on the hull, and one long shaft held them aligned while curing.
The shaft diameter is 6mm (app. 1/4").
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The next day, the shaft was removed,
and any excess resin was removed. Now it was time to test-fit the
rudders, that had also cured over night.
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The clearance between the dive plane shafts, and the
rudder shafts, are just as it should be. The propeller shaft will run
right through the middle, thus leaving only very little room for
mechanical travel.
However, the maximum rudder movement are set by that fact that the
rudders and the dive planes can get into outside contact, if the angles
on either exceeds app. 40 degrees. This will be programmed into the
remote later on.
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This is the finished result.
The dive planes are angled down due to their own weight, as none of the
control surfaces has been linked yet. The rudders move just as easy, and
the overall impression is satisfying.
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Well... I HAD to see what it looked
like, with the propeller fitted as well.
It's pretty amazing that all three axis of the sub is controlled from
this relative little area on the sub, and it's going to be interesting
to see it work in it's real environment some day..
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This image from very late in the
building shows the fitted rods for the control surfaces, and the wires
for the aft upper rudder navigational light. |
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This image from very late in the
building shows the now complete linkage to the rudders. Space is left in
the very middle for the prop shaft, one of the next things that goes in.
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This shows the completed ridder shaft arrangement. The push rods go through holes in the bridge that also supports the oil-bearing for the prop shaft. This should give the push rods extra stability. |
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| Close-up of the support bridge for prop shaft and rudder rods. |
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| This is the overall lingage from WTC1 and to the props and rudders.
The small light brown block with three holes in it towards the very aft has since this been removed.
The metal thing towards the hull edge is the zink plate, preventing corrosion. |
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The dive planes on the sail are fitted
on one long shaft, extending all the way through the sail. Within the
sail, and on the shaft, a similar servo horn is fitted. As this horn is
supposed to point straight forward in order to make room for the
periscopes, the dive planes are angled so that the horn points straight
down while curing. This ensures that it will not slide around, and get
out of alignment.
The sail- and aft dive planes can be linked to the same servo, or
one of the pairs can be linked to their own individual servo, through an
automatic leveler control. |
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I choose to link it to the aft linkage
by mechanical means. (Circled in red in picture)
This images shows the magnet fitted to the pushrod from the dive plane
servo.
The magnet was glued to an ordinary 3-way rod connector similar to other
rod connector in the picture.
The magnet sticks above the center of the hull, so the magnet in the
upper part will not extend under the lower edge, as that might damage
it, when the top is put down normally. (E.g.. not up side down.) |
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This shows the inverted missile deck
with the counterpart. The blue tubing holds a long rather flexible
plastic rod.
The blue tube and the rod is called "Golden rod" and is normally used to
transfer mechanical force in planes, as not-straight path are often
needed.
Again, a magnet was glued to a 3-way rod connector. |
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This is the mechanism that goes under
the sail, transferring the mechanical movement to the sail planes,
inverted to the aft dive planes.
The arm on the far side will later serve as a fixing point for the wires
going to the light in the sail. |
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Here it's fitted, and the Golden Rod
is connected.
If looking into the sail (top half inverted in picture), you can see how
the longer of the two arms is attached to the servo horn on the dive
plane shaft.
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This shows an overall view of the
Golden Rod, and the entire mechanism.
The mechanism will not interfere with the scopes. (Not in picture.)
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