If I was casting a cylinder and with the shrinkage would the ID get bigger and the OD get smaller
Mike
Casting a cylinder
Casting a cylinder
When life gets tough, remember: You were the strongest sperm 
Re: Casting a cylinder
probably end up with shrink tears in the wall, with something as thin as a drum shell but then its hard to tell what the metal is going to do untill you pour it. I would think that the way to pour would be to run the sprue down the center and have runners that go from the sprue to the shell so you can feed it in four or five places, with one BIG A#$ Sprue probably have to be three inches in diameter.
But I don't know how big Latz is wanting to make it. might be one of them little tiny drums like 6 inches high by 8 inch diameter but I kinda have this feeling thats not what he's wanting
But I don't know how big Latz is wanting to make it. might be one of them little tiny drums like 6 inches high by 8 inch diameter but I kinda have this feeling thats not what he's wanting
David and Charlie aka the shop monster
If life seems normal your not going fast enough" Mario Andrette
If life seems normal your not going fast enough" Mario Andrette
Re: Casting a cylinder
What I was going to make was a round 6 inch air cleaner can pattern for a mates Harley and I was just wondering which way it would shrink, even tho I really don't think shrinkage will be a issue
Mike
Mike
When life gets tough, remember: You were the strongest sperm
Re: Casting a cylinder
Mike, shrink is overall I believe so the ID would get smaller along with the OD. Really though unless it is a critical part I dont think you are going to see enough to worry about in that small of a part, if you do then add a little to the outside of the pattern if you can using a high build paint. Oh yeah and use a good alloy to minimize shrink in the first place.
I'd rather laugh with the sinners than cry with the saints the sinners are much more fun...
Muller
Muller
Re: Casting a cylinder
The shrink won't be a problem Harry, I was just wondering which way a cylinder would shrink as in ID bigger OD smaller so wall thickness would be less. I'll make and measure it and see which way it goes
Mike
Mike
When life gets tough, remember: You were the strongest sperm
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latzanimal
- Posts: 408
- Joined: Wed Jun 01, 2011 10:58 pm
Re: Casting a cylinder
I am glad to see I've stoked some fires... 
While I have no idea what shrinkage will happen, my plans have been to account for shrinkage in all directions. However, the drum shell is possibly a bit more critical on final size than your air cleaner. I may be wrong.
I, as well as others, are curious to you results Mike. Please keep us informed....
While I have no idea what shrinkage will happen, my plans have been to account for shrinkage in all directions. However, the drum shell is possibly a bit more critical on final size than your air cleaner. I may be wrong.
I, as well as others, are curious to you results Mike. Please keep us informed....
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latzanimal
- Posts: 408
- Joined: Wed Jun 01, 2011 10:58 pm
Re: Casting a cylinder
Dave, do you think it would start to cool too fast using a sprue outside the pattern or would it just make for a more even pour running from the inside?
Re: Casting a cylinder
by pouring with the sprue in the center you will get a more even faster pour, as long as the runners are big enough and the sprue has enough melted metal in, it it will feed the casting "drum shell".
if you pour from the outside you run the risk of a short pour if the metal isn't really hot. this is one of those pours that the bronze is going to have to be at around 2300 so it will run like water.
The other thing is that I just don't see any fast way to pour this without putting the sprue in the middle with say four runners into the shell that way the metal fills from the bottom all the way around but with it being 13.8 in diameter I would use 5 one inch runners from a large tapered sprue, possible that some shrink bobs would also need to be throwed in also.
To gate it on the outside you would have to have a pretty good size runner around the part into at least three points for it to fill close to evenly.
Mike I think the biggest problem that you will have is getting the melt hot enough, what happens is that when you pour the metal into the mold it starts to cool from the thinnest part. or the part thats the longest distance from the sprue where the hottest metal is, also shrink tears are caused when the metal cools in a thin part but can't pull metal into the area from the rest of he part it will tear. HD air cleaner is about 7 inches in diameter if you make it an 1/8 inch think you should be good to go just pour it hot, use a good degas procedure so it will polish up nice, harley owners are known for their love of chrome polish, some even put it on their toast.
if you pour from the outside you run the risk of a short pour if the metal isn't really hot. this is one of those pours that the bronze is going to have to be at around 2300 so it will run like water.
The other thing is that I just don't see any fast way to pour this without putting the sprue in the middle with say four runners into the shell that way the metal fills from the bottom all the way around but with it being 13.8 in diameter I would use 5 one inch runners from a large tapered sprue, possible that some shrink bobs would also need to be throwed in also.
To gate it on the outside you would have to have a pretty good size runner around the part into at least three points for it to fill close to evenly.
Mike I think the biggest problem that you will have is getting the melt hot enough, what happens is that when you pour the metal into the mold it starts to cool from the thinnest part. or the part thats the longest distance from the sprue where the hottest metal is, also shrink tears are caused when the metal cools in a thin part but can't pull metal into the area from the rest of he part it will tear. HD air cleaner is about 7 inches in diameter if you make it an 1/8 inch think you should be good to go just pour it hot, use a good degas procedure so it will polish up nice, harley owners are known for their love of chrome polish, some even put it on their toast.
David and Charlie aka the shop monster
If life seems normal your not going fast enough" Mario Andrette
If life seems normal your not going fast enough" Mario Andrette
Re: Casting a cylinder
I mostly have Vegemite on my toastdallen wrote: harley owners are known for their love of chrome polish, some even put it on their toast.
And the way the damn weather is here at the moment its going to be awhile before I can do anything
Mike
When life gets tough, remember: You were the strongest sperm
Re: Casting a cylinder
http://hyperphysics.phy-astr.gsu.edu/hb ... thexp.html
Here's some equations for thermal expansion, shinkage is the same amount as it cools. A hole in a plate will become smaller as it heats, but I believe a cylinder will have a larger ID when heated, like a bearing race you heat so it will fit on a shaft. I think you treat a cylinder as a flat surface plate.
Here's some equations for thermal expansion, shinkage is the same amount as it cools. A hole in a plate will become smaller as it heats, but I believe a cylinder will have a larger ID when heated, like a bearing race you heat so it will fit on a shaft. I think you treat a cylinder as a flat surface plate.
