The following photo
tutorial will describe how to prepare, turn, finish and assemble
an EPR Egg-Scope. First, you'll need an EPR egg block, available
exclusively through Arizona
Silhouette. You'll also need a Kaleidoscope kit, adjustable
pen mandrel, bushing set, a 13/16" drill bit,
wet sand paper, various hand and power tools, eye protection
and a dust mask of some kind.
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 First,
put on your safety glasses and dust mask. Then secure
your EPR block in some kind of holding fixture.
I'm using a 10" wood clamp to hold the block
securely while drilling. Mount your 13/16"
Forstner bit in the drill press so that at
least 2.5" of drill shaft is exposed below
the chuck.
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.
 Now
drill a hole through the center of the block. Clear
out debris and shavings often. When getting close
to the exit point, drill slowly and preferably into
a sacrificial piece of wood under the EPR block
to avoid blow-out. Alternatively, you could drill
just short of the exit point and sand or band-saw
off the excess.
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 At
this point, your EPR block should be about 2.5"
long. The length needs to be reduced to 2.25".
I'm using a 6" belt sander to take the block
down to its final dimension. Be careful to leave
a little extra length on the block until you are
sure that the block's ends are true and 90 degrees
to the hole.
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 Assuming
your 13/16" hole is centered on both ends,
you could use a square to check that the ends are
90 degrees to the block's sides.
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 This
photo shows an adjustable # 2MT pen mandrel and
a pair or bushings, purpose made for this kaleidoscope
kit. Note that the mandrel's length has been shortened
so that extra bushings are not required.
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 Also
note that the EPR block has been sanded down to
exactly 2.25" in length and that the ends are
flush and snug against the bushing's outer lip.
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 Here
you can see the mandrel mounted in the lathe's #2MT
headstock. There is a live center in the tailstock,
that has been snugged up to the end of the
mandrel. Place your tool rest as close as safely
possible to the turning and about 1/4" below
the center line. Also note that I've got a vacuum
hose set up close to the turning...avoid breathing
that dust!
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 EPR
turns best with a skew, requires a light touch and
light shallow cuts. You can also use a flat or round
nosed scraper, but not as effectively as a
skew. Parting tools can also be used successfully
under some circumstance. Experiment with your hand
tools to find what works best for you.
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 Here
you can see that the basic egg shape has been
rough turned. I used a 1/2" round-nosed scraper
with the burr removed for this operation. You'll
need a very sharp tool and take light cuts to avoid
dig-ins and a "shattered glass" look.
If you do encounter the "shattered glass"
look, switch to another cutting tool and try again.
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Here, I'm using a sharp 1"
straight-edged skew to clean up the rounded surface
of the egg. Again, note that the tool rest is very
close to the turning. It needs to be close to avoid
chatter and dig-ins
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 .
The best way I've found to approach a turning with
the skew is to lay it on top of the piece, then
gently bring the cutting surface down until the
tool's bevel meets the piece and begins to cut.
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 A
thin parting tool is being used to finish a hard
to get to area.
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|
 So
now we're all done with the cutting and ready to
sand. Always wet sand plastic. I've put a towel
on the lathe's bed to keep it dry and rust-free.
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 This
is Silicon Carbide wet/dry sand paper cut into 2"
squares. From left to right, I'm using 240, 400
and 600 grit papers.
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 Get
your sand paper good and wet and turn the lathe's
speed down as slow as possible. You know you've
got the paper wet enough if you're getting
a nice slurry and not dust.
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 At
this point, we've gone through each of the three
grits of wet sandpaper while the lathe is running.
Next, I'll turn the lathe off and hand-sand the
piece for a minute or so in the direction of the
headstock, with the wet 600 grit paper to remove
fine scratches.
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 From
here, it's a matter of personal preference as to
how to finish the piece. Some turners will use wet
micro mesh. Others will use a compound like Novus
2 plastic scratch remover.
|
 Novus
works reasonably well and will remove any remaining
scratches from properly sanded plastic pieces.
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 However,
I prefer to buff using the first two wheels of the
Beall system (Tripoli and White Diamond) immediately
after wet-sanding. A robust Tripoli buff will
remove 100% of any residual scratches and the White
Diamond is a very effective final polish.
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 Here
is the finished egg turning and the components of
our kaleidoscope kit.
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 Elements
of the kit, from top left to right are: three mirrors,
threaded mirror retaining tube, plastic color
bits, paper ring, two clear flat lenses, color bit
threaded retaining end-piece, lens retaining spring-ring,
clear curved lens and threaded peep-hole end-piece.
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|
 Remove
the protective plastic covering from the curved
clear lens.
|
 Place
the lens into the peep-hole end piece, curved side
facing down. Drop in the retaining spring-ring.
|
 Use
the head of a finishing nail to position and "pop"
the retaining spring-ring into place, so that
the lens is held firmly in place.
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|
 Now
set the peep-hole threaded assembly aside and collect
the parts for the color bit threaded retaining end
piece assembly.
|
 Remove
the protective plastic film from both sides
of the clear-flat lens.
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 Drop
the lens into the color bit threaded retaining end-piece.
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 Next
drop the paper ring into the end-piece, making sure
it is seated firmly against the first clear lens.
|
 Now
you still have one clear flat lens and the colored
plastic bits awaiting assembly.
|
 Remove
the colored plastic bits form the bag and put all
but 2 to 5 of the bits into the end-piece.
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|
 In
this example, I've held back three of the larger
pieces. If you use all of the supplied colored bits,
the container will be too full and your kaleidoscope's
color pattern will not change when rotated.
|
 Remove
the protective plastic film from the second clear
flat lens.
|
 Now
place the second lens into the threaded end-piece,
sealing the colored bits in the color wheel chamber.
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|
 Screw
the threaded mirror retaining tube into the end
piece. At this point, the colored bits should be
secured and will not fall out of the assembly.
|
 Holding
the threaded mirror retaining tube parallel to the
floor, place the first two mirrors into the tube,
making a V. Note that each of the three mirrors
has a black line marked on one side. The black lines
should be facing out.
|
 Now
slide the third mirror into place, making a triangle.
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|
 Invert
the assembly and tap it lightly on a table so that
the three mirrors come out of the tube about half-way.
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 Make
sure the three mirrors are each extended the same
distance.
|
 Using
a 1.5" long piece of common Scotch tape, wrap
the three mirrors so they will only move as a set.
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 Here
you can see that the tape has been wrapped around
the three mirrors.
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 Gently
but firmly, slide the three mirror assembly back
into the threaded tube. Some amount of force may
be required to push the mirrors into place, but
be gentle.
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 Ready
for final assembly...slide the colored plastic bit
assembly into one end of the egg's hole. Then thread
the peep-hole assembly onto the mirror retaining
tube from the other end.
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 And
you're done...
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