For those of you interested in making your own castings but don't have CAD or NC equipment here is a good example of what can be made with wood working equipment.
Obviously the skill requirment is high and the time expended is massive.
Don't feel too dissapointed if your first attempts don't look so nice as this, this is really exceptional fine work for wood pattern making.
FYI, doing it in CAD and CNC would cut the time in half or more.
http://www.dmdaustralia.com.au/block1.html
Woodshop pattern making
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Re: Woodshop pattern making
[size=150][url]http://www.SportsCarDesigner.com[/url] [color=deeppink].... You [u]want[/u] to design your own car... so go ahead.[/color][b] Sports Car Designer [/b][color=deeppink] is the answer.[/color][/size]
What else can you do with that gift card you got?
What else can you do with that gift card you got?
Just realized, after seeing this picture...
... that if you step it just right, a single simple core box for half a cylinder pair can generate all the cores ( i.e. 8 for a V8 ) for the all the bores and crankcase bays...
... that if you step it just right, a single simple core box for half a cylinder pair can generate all the cores ( i.e. 8 for a V8 ) for the all the bores and crankcase bays...
[size=150][url]http://www.SportsCarDesigner.com[/url] [color=deeppink].... You [u]want[/u] to design your own car... so go ahead.[/color][b] Sports Car Designer [/b][color=deeppink] is the answer.[/color][/size]
What else can you do with that gift card you got?
What else can you do with that gift card you got?
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Yes mostly, except the end cores on V8s have more length to make space for the thicker counterweights and most crankcases aren't left/right symmetrical so that matching half cores doesn't work out too often.that if you step it just right, a single simple core box for half a cylinder pair can generate all the cores ( i.e. 8 for a V8 ) for the all the bores and crankcase bays...
That clay looks a lot more fun than using a mouse and keyboard.
Hmm... maybe a spacer or insert in the core box...
[size=150][url]http://www.SportsCarDesigner.com[/url] [color=deeppink].... You [u]want[/u] to design your own car... so go ahead.[/color][b] Sports Car Designer [/b][color=deeppink] is the answer.[/color][/size]
What else can you do with that gift card you got?
What else can you do with that gift card you got?
Thanks for finding and posting up that picture series, very helpful in getting a feel for what all is involved in low volume casting development.
With complete wood core forms like shown above, is there a way to ball park the finished cost of a simple casting? Perhaps based on weight of metal in the casting or are the setup and core forming steps too unique from case to case to even ball park costs.
In a machine shop envirionment, you can usually get an educated estimate for a one off part, based on the cost of materials plus a fudge factor for how complex the machine processes will be.
Larry
With complete wood core forms like shown above, is there a way to ball park the finished cost of a simple casting? Perhaps based on weight of metal in the casting or are the setup and core forming steps too unique from case to case to even ball park costs.
In a machine shop envirionment, you can usually get an educated estimate for a one off part, based on the cost of materials plus a fudge factor for how complex the machine processes will be.
Larry
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Sort of, weight is a small portion of the cost. The main cost is in the time required to fit all the sand pieces together. For example the tunnel rams you see in Jegs that sell for $200 cost about $145 from the foundry using high volume tooling. There are only three pieces of sand involved and two of them are soft sand (green sand) and one is hollow (a sheel core)is there a way to ball park the finished cost of a simple casting?
The manifold I make has 6 pieces of sand, all of them hard chemical bonded sand (like they used on the engine block) and the combined size of the sand is 2 or 3x bigger. This is so the plenum can be cast with the runners. So this part costs about $400 from the foundry because it takes a lot of time and skill to assemble all the sand pieces without damaging them.
Most low volume heads can be done for about $400 each.
Blocks run about $1800 to 3,000 depending on complexity.
These prices are at a good foundry that knows automotive racing castings.
An aerospace place will cost 2 to 3 times more.
So if you are making about ten castings, the cost of the castings are trivial compared to the investment in tooling.
To give you an idea how something like the block pattern would be done with CAD CAM; instead of making all the small shapes and glueing them together, I would just glue up a bunch of wood into a big block and cut the entire shape into it. About the only time I measure anything is when I am sawing the wood before glueing it together and thats with a tape measure.
Now I'm getting away from using wood. I'm cutting a negative of the pattern I want into large blocks of machinable wax then casting eurethane patterns from them. The wax costs the same by volume as aluminum or eurethane, the difference is that I can remelt the wax. Right now I'm working on a system to do that more efficiently, I bought a big 60 gallon steam kettle and I'm making some molds for different size wax blocks. This has delayed progress on my V12 but I am sick of the wood dust in my shop.
If you want to try the wood method, try MDF (yeah the stuff at Home Depot) it is really cheap and so far I dont see any disadvantage to it. I have done some hardness tests on it and I think it is harder than any Mohagany I have in the shop not to mention no grain and almost free in comparison. Use poplar or ash for the structural parts and birch plywood for the big flat parts that need to be strong.
If you don't have good woodworking equipment, lots of Community colleges do. Where I live Coast Line College has really primo stuff and no one uses it much.
That said if someone just wanted to make patterns they could buy a CNC router for about 4K and make patterns in their garage on 220 single phase. Guys who will square-up manifolds and put holes in them for $50 are common.