Custom made Multi-Bit Set

Here is a snap shot from the sky copter displaying a pattern being set up with risers. The side with risers is known as the cope of the casting/pattern.

A riser or feeder is a reservoir built into a metal-casting mold to prevent cavities due to shrinkage. Because metals are less dense as liquids than as solids (with some exceptions), castings shrink as they cool. This can leave a void, generally at the last point to solidify. Risers prevent this by providing molten metal at the point of likely shrinkage, so that the cavity forms in the riser, not the casting.

This only works if the riser cools after the rest of the casting. Chvorinov's rule states that the solidification time t of molten metal is related to the constant C (which depends on the thermal properties of the mold and the material) and the local volume (V) and surface area (A) of the material, according to the relationship

t = C \times \left (\frac{V}{A}\right)^2.

Therefore, to ensure that the casting solidifies before the riser, the ratio of the volume to the surface area of the riser should be greater than that of the casting. The riser must satisfy two requirements: it must be large enough so that it solidifies after the casting (i.e. satisfies Chvorinovs rule) and it must contain a sufficient volume of metal to supply the shrinkage contraction which occurs on cooling from the casting temperature to the completion of solidification. This latter requirement will be more important for plate like shapes; the former will be more important for chunky shapes.

Because risers exist only to ensure the integrity of the casting, they are removed after the part has cooled, and their metal scrapped. As a result, riser size, number, and placement should be carefully planned to reduce waste while filling all the shrinkage in the casting.

That last part about reducing waste always induces a chuckle or two.

Sources
Wikpedia
Bay Cast
And ME

Velvet Yesterway

I am sure you all heard the quote... "Necessity... the mother of invention." by Plato. Well in my case its:
"Laziness is the bear necessities."
-PW
This little crude contraption(see figure 1.0) I rigged up in about 15 minutes saves me an average of two and a half hours per job. And as of now there are two jobs that need to be taken care of. This contraption uses space age hot wire technology to cut polystyrene patterns otherwise known to you lesser people as Styrofoam patterns.

When I say job i mean a rainbow shaped piece of polystyrene. (as seen in figure 1.1) It has a diameter, from outside edge to outside edge, of roughly 20 feet. Its height is 49 inches with a thickness of 16 inches.In figure 1.1 you see the pattern standing up, the view shows the thickness and length but not the height.

My mission whether I like it or not is to cut it down to a height of 29 inches. The given method of using a handsaw or a saws all takes anywhere from two and a half hours to all day depending on how I feel that day.

I now open the floor for Q & A.

Stalagmite pushes up with all its mite!

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Intro
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My sinuses are pretty much all f'd up and it is to bright outside.
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Story Line
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Yeah so its final the guy at work isnt coming back to work anytime soon, his doctor put him on disablilty. and his brother is retired and I heard that they are bringing an R Tard from the other plant across town to help ram up patterns.

I found out that in 2002, bay county ranked among the dirtiest/worst 10% of all counties in the U.S. in terms of total environmental releases. I.E. pollution producers. I am suprised Bay Cast isnt found in this website anywhere. There are other companies that i know have less waste than Bay Cast that are found there but not one word of them... makes me think a little bit about what is really going on.
click here to see how your community ranks.
www.scorecard.org
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Intermission
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After much anticipation i am unveiling my newest goal.
Traveling lower Michigan and visiting all the recognized cities and viliges as defined in the State of Michigan website. My goal is to have at least 60% done by the end of the year.

Remember if your looking for crystals look for stalagmites.
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Fin
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Large Swissman's Last Symphony

Yeah this guy at work went into the doctor this week and so far he hasnt returned and rumor has it the doctor said he couldnt work anymore and that he should be on disablity. This coming two days before his brother is to retire.

Its a good thing Bay Cast is really slow and that there isnt any castings that need to be rammed and poured now that half of the crew is going to be gone.