Casting Ruler

Home enthusiasts discuss their Foundry & Casting work.

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captainkirk
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Casting Ruler

Post by captainkirk » Mon Jan 06, 2003 7:03 am

I found a Lufkin shrink ruler a local Antique shop it's kind of expensive and I'm not sure how usefull it will be for making patterns. Can you still get these type of rulers and if so where/
What shrink values are used for the different types of metal
Aluminum, brass/bronze,iron, etc.

Harold_V
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Re: Casting Ruler

Post by Harold_V » Mon Jan 06, 2003 8:24 am

Hey Cap'n,

Yeah, shrink rules are still available. Starrett sells them and I'm sure others do as well. I bouught two of them a few years ago, one a Starrett C370, 1/8"/ft. shrink and the other a Starrett C375, 3/16"/ft.. These rules are a nice satin chrome finish and very easy to read. Current catalog price is $55 each. [img]/ubb/images/graemlins/shocked.gif"%20alt="[/img]

In general, proper shrink for iron is 3/32"-1/8"/ft., yellow brass 7/32"/ft., common brass 3/16"/ft., bronze 5/32"/ft., steel 3/16"/ft.. It appears that values are variable, which makes sense to some degree. Pouring temperatures would have a profound effect on the amount of contraction, along with other factors. [img]/ubb/images/graemlins/smile.gif"%20alt="[/img]

Hope this helps some~

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.

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captainkirk
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Re: Casting Ruler

Post by captainkirk » Tue Jan 07, 2003 6:44 am

Thanks for the reply, that's the info I needed

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JEB
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Re: Casting Ruler

Post by JEB » Tue Jan 07, 2003 2:03 pm

That reminds me of when I first went to work for the company that I just retired from. One of the tools I had to buy before I reported to work was a 6" scale. So I went down to the old time hardware store in town and bought what I thought was a 6" scale. I used it for several years until I happened to lay it down to another 6" scale. Hmmmm, why is mine a little longer than the other one? Took a close look and it read "shrink rule 3/16" / ft". Took a lot of ribbing that day. [img]/ubb/images/graemlins/smile.gif"%20alt="[/img]

Jim

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WSHBaker
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Re: Casting Ruler

Post by WSHBaker » Tue Jan 07, 2003 8:44 pm

That must have been about 1960 give or take. Right? [img]/ubb/images/graemlins/smile.gif"%20alt="[/img]

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GeneT
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Re: Casting Ruler

Post by GeneT » Tue Jan 07, 2003 9:41 pm

Anyone know of an economical source of rules *now*? I love my Starret stuff, but $55 bucks for a ruler seems a bit pricey, even with the Starret name. GsT

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GeorgeGaskill
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Make your own using an old-style triangular ...

Post by GeorgeGaskill » Wed Jan 08, 2003 7:06 pm

draftsman's ruler. Make a 1:1 drawing of a ruler using your CAD program, then print it out at differing scales such that you get the extra 3/8" per foot (or whatever you need) in the printed version. Cut it out and glue it to the ruler. You can have six scales on one stick.

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generic
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Re: Casting Ruler

Post by generic » Wed Jan 08, 2003 10:38 pm

There is a specific method taught in drafting class, well it used to be [img]/ubb/images/graemlins/smile.gif"%20alt="[/img]
A pic is attached (I hope).

A ruled line is drawn vertically, another is pivoted at a common corner(becomes center of radius) and lengthened to the proper radius.
Then equally divided (12 spaces.)
Then marked at these divisions which 'each' have their share of the total expansion.

Yes, its a manual method. But doable in cad and printable.

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GeneT
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Re: Casting Ruler

Post by GeneT » Wed Jan 08, 2003 11:18 pm

Doh! Cool, I hadn't even thought about making my own! I'm thinking now, that even without CNC a rule could be engraved pretty well with a manual machine. Another project! (#768)
Thanks guys,
GsT

coldformer
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Re: Casting Ruler

Post by coldformer » Tue Jan 14, 2003 1:16 am

hello
i just use a calculator and dual dim my drawings (doodles)
jerry

coldformer
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Re: Casting Ruler

Post by coldformer » Tue Jan 14, 2003 1:20 am

aluminum 8-12% + beer factor
jerry

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Rolly
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Re: Casting Ruler

Post by Rolly » Wed Jan 15, 2003 7:56 am

Thanks generic
Cheep was to lay out a scale. I use AutoCAD

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