Any Sand Casting Drawing Examples

[aeromk]

I'm looking for link(s) to show examples of sand casting drawings and its corresponding machine drawing. To see how datum planes and points are placed. Since I have to soon begin my own drawing on a hollow circular part with an odd shape flange. Thanks for links.

 

[Cierpy]

hello

first thing, you need to find the machining stock and the tollerances you have to use on the sand casting.
applying this information it will be easy to define your drawing of the casting.
today many enginners are making "bad" drawings because they don't know the machining stock and the tolerances they have to apply

What you are looking for: aluminum sand casting or iron sand casting ??

regards

 

[aeromk]

The casting material will be aluminium, premium quality sand casting part for aircraft. Meaning, minimum amount of addition material to be added for casting.

 

[BillPSU]

If indeed, you need a sand casting you need a lot more information than just the machining stock. You need to determine the parting line and where to locate it. The draft angle needed to pull the pattern from the sand. The core requirements. The spots where shrink will be a problem. The gas level allowable in the casting.

Short run castings can be made with the rapid proto-typing process but casting quality may suffer due to poor gating and risering. You really need to talk to you casting provider and get him involved early in the process.

If the volume is great enough several other casting processes could also be considered including: permanent mold, die cast, or investment casting. Even within the sand molding processes there is there is different processes such as green sand or no-bake or shell mold.

 

[GRoberts]

I'll second the advice to contact the casting suppliers to have them work with you on the part. You know what you want your part to do and how it need to perform. You are the expert there. Your casting supplier is the expert on what they need in order to make the part as far as tolerances, manufacturability, etc. The earlier you get them involved in the process, the easer it will be to design a part that will be easy to manufacture.

 

[Cierpy]

I complety agree with the recomendations of the other engineers - I also like to recomend to contact your casting supplier ASAP in order to define the project and get all the information you need.

 

[arunmrao]

aeromk,
you have your component drawing and submit to the casting manufacturer. He shoud be able to come out with a casting drawing and pattern drawing.

Take care of any thick and thin section junctions, negative tapers, general machining allowances( sand casting needs more allowance than gravity casting).Any complicated cored hole paths and pressure tightness if needed. Also specify the NDT requirements ,methods,locations and acceptance before making the pattern.

These are some of the major guidelines while developing a new pattern.

 

[ewh]

The above are all good posts. You will also have to determine your datums. Since this is a casting, there probably will not be any good surfaces for them.
The way I have accomplished this on a complex aerospace casting was to 1) establish the primary plane, consisting of three spotfaces in the part, 2) establish the secondary plane with two spotfaces (perpendicular to the first datum), and 3) establish the tertiary plane with one spotface (mutually perpendicular to the first two planes). This gives the machinist a good foundation for any further work.
I hope that this helps!