Printable View
Hi,
my final year university project consists in the realization of 4 pelton buckets (e.g. in attachment). I have to realize these buckets by sand casting process butn i don't know how to achieve the ellipsoidal shape with cores. Do you have any suggestion?
Thank you very much
I don't believe that you would need separate cores to achieve an "[COLOR=#333333]ellipsoidal shape" as long as the deepness of the feature is parallel to the casting molding separation direction. The thin wall between the [/COLOR][COLOR=#333333]ellipsoidal shapes as well as the lack of radius blends are problematic.
Be aware that it may not be necessary to achieve the final geometry with sand cast. As-cast geometries are commonly post-machined to achieve un-castable geometries, mechanical tolerances, etc..
Have you consulted your casting manufacturing job shopper or equivalent professional?[/COLOR]
I know that final geometry can't be achieved by using sand cast; i can't also use CNC machines so how can i realize a similar geometry (including the ellipsoidal shape) and then post-machine it using traditional tools (hobby mill,hobby turn,drill, etc..)?
Sand casting will require at least wooden molds, which can be made easily by wood shop methods. The actual curve can be specified with patterns if automated equipment is not available. The patterns can easily be constructed with any CAD system. Talk to whom ever is going to make the molds for the sand, typically called a "pattern maker".
Timelord
[quote][COLOR=#333333]i can't also use CNC machines[/quote]
Can you 3D print the pattern (most of it anyway)? Some casting organizations are creating the cast part pattern from 3D printing...[/COLOR]
The core is held in position by supporting geometry called core prints If the design is such that there is insufficient support to hold the core in position, then metal supports called chaplets are used. The chaplets will be embedded inside the final part.