hello all. Has there ever been an article or discussion on casting plane or tool bodies in brass or bronze. Questions I would like answers to. 1. if I make a wooden pattern what percentage over size do I need to make it (if at all) 2. is the cost per weight of finished casting (in its rough state). what are the chances of F/W doing an article on plane making as there seems to be a following for original hand made planes.
regards Teabag.
Replies
You will definately have to make it over sized, but you will need the proper shrink rule to make your woodin pattern. And that where my pattern making knowledge ends.
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Bruce S.
I've personally done bronze casting from a sculptural process so you don't need to worry about shrinkage for the most part. I've also had stuff cast locally by a small bronze plaque making shop.
. You should find a local caster who will tell you how to make the pattern. Things to know are the draft and shrinkage. Making a part too thick will affect a neighboring part thats too thin. There's a certain element of balance required. Look at cast stuff in your shop for some ideas. There's plenty of old trade school books on casting. Also many casting forums out there. Way too advanced for a wood magazine. You local caster should tell you what he needs to do the job. Make it difficult for him and it will cost you more. Work with him and you will learn. I've got some shops that still do it the old way with a wood pattern and sand casting. Other shops will make a master from a dxf file and snad cast it as well. You are beyond the wood forums for this. Seek out the casting forums. Metal is even more diverse than wood. You have machinists, ,metal casting, sheet metal and more so target your search.
Shrinkage allowance for Bronze is 5/32" per foot. Make the pattern with draft of 1/16" per foot so you can withdraw it from the sand. Cast it in bronze #63 is Leaded gun metal bronze. It has fair machining qualities.
John
If you are going to get into pattern making for casting try to find a pattern makers rule it is marked in various metals with the appropriate dimensions to allow for shrinkage etc..It simplifies the pattern making process you pick the metal of choice and use those dimensions for your pattern,bit like a funny scale rule.
Regards from Melbourne OZ
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