Ed's Polyester Resin (EPR)
 

Egg Kaleidoscope Tutorial 

yoyo@yoyospin.com

The following photo tutorial will describe how to prepare, turn, finish and assemble an Exotic Blank Egg-Scope. You'll 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.



Exotic Blank Egg-Scope blocks measure approximately 2" in diameter and 2.5" tall, giving you about 1/4" of extra length required for the finished scope.
 

Click on each photo below to view a larger image.



First, put on your safety glasses and dust mask. Then secure your Exotic Blank 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 Exotic Blankto avoid blow-out. Alternatively, you could drill just short of the exit point and sand or band-saw off the excess.

 

 



At this point, your Exotic Blank 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.

 

 

 

 



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.



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.



Also note that the Exotic Blank has been sanded down to exactly 2.25" in length and that the ends are flush and snug against the bushing's outer lip.



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!



Exotic Blank 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.

 



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.
 


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

 



. 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.

 



A thin parting tool is being used to finish a hard to get to area.

 


 



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.

 



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.

 



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.



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.



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.

 



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.

 



Here is the finished egg turning and the components of our kaleidoscope kit.

 

 

 



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.



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.



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.



Drop the lens into the color bit threaded retaining end-piece.



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.

 

 



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.

 

 



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.

 

 



Invert the assembly and tap it lightly on a table so that the three mirrors come out of the tube about half-way.



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.
 



Here you can see that the tape has been wrapped around the three mirrors.


 



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.



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.



And you're done...

 

 

 

 

Have a question or comment? Send Ed and email.


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