Creating Stainless Steel Prototype Parts: A Guide to Combining Techniques

[mikex24]

Hi, I have a question: I would like to describe how can i use a combination of techniques (numerical control machines excluded ) to produce a batch of a prototype part (approx 45 pieces) using stainless steel as my material and vacuum cast as the manufacturing process. Any ideas ? Thanks

 

[Fish4Fun]

mikex24,

Vacuum casting is well outside my experience zone; I assume you have the equipment and a rich knowledge of the processes, but in the event you do not, I found this on the topic:

http://www.metalcastingdesign.com/content/view/480/314/

Following is an excerpt from the above link:

This method of vacuum casting is used in the permanent mold, diecasting, investment casting and sand casting processes. Choosing the molding method for vacuum casting usually follows the same guidelines as choosing the molding method for typical gravity pouring.

“If it’s low volume, a part lends itself to gravity or vacuum cast sand,” Bumbar said. “If it’s higher volume, we’ll usually go gravity or vacuum cast permanent or semi-permanent mold.” In addition to quantities, the size of the castings also plays an influential role in determining the type of molding process utilized.

Hopefully someone here will be able to give you firsthand advice.

Fish

 

[brewnog]

Can you describe the part?

 

[mikex24]

Hi, Thanks for the help, the link description the process very well. The part is a solid circle with thickness 5mm and diameter 50mm which has a hole in the middle and a bush around the hole. It is one piece with the same material(stainless steel). I am not sure what is mean : combination of techniques (numerical control machines excluded ): so any help on this will be appreciated. What that means on vacuum casting process? Thank you again for the help

 

[brewnog]

No idea why you'd want to vacuum cast that component. For a run of 45 parts it sounds like you would be better off machining that from bar stock. It'll cost a lot to tool up for such a prototype casting run, and the part would need machining anyway if a bush is to be fitted. Material cost will be insignificant.

 

[mikex24]

not sure why to use this process but i was told to describe this combination of techniques to produce this part with vacuum casting. So am asking which are these techniques and why to use this combination of techniques. thanks

 

[Fish4Fun]

If this is a class exercise, perhaps the answer is as simple as my link/quote suggest. If this is an industrial project then the only reason I can think of for vacuum casting 45 such simple parts is "proof-of-concept" for a very large production run. If the latter is the case, then you should prolly explore "vacuum casting sand" molds, but I find it very odd that any large production run would gain much information from vacuum casting 45 parts, regardless of method.

Anyway, perhaps you should give a bit more background information about the question so that the right people can respond to it with helpful advice.

Fish

 

[mikex24]

Hi, It is a class exercise and the part is for aircraft use.

 

[brewnog]

Remember the thing you agreed to about posting homework questions?

 

[mikex24]

yes i understand but as you see at the beginning i don't want a solution to my exercise, but a guidance what that means and then to solve it by myslef.

 

[mikex24]

Hi again, I am trying to solve this question and i would like to help me on this. How can i machine a part who i created it on a 3D CAD system without using NC machining? It is necessary that the part have to be accurate on dimensions etc...

http://en.wikipedia.org/wiki/File:CAD_model_and_CNC_machined_part.PNG

check this picture. Here it machined by 6-axis NC. I wanted the same results but not using NC machining. What else can be used for this?

 

[Jasongreat]

Hi again, I am trying to solve this question and i would like to help me on this. How can i machine a part who i created it on a 3D CAD system without using NC machining? It is necessary that the part have to be accurate on dimensions etc...

http://en.wikipedia.org/wiki/File:CAD_model_and_CNC_machined_part.PNG

check this picture. Here it machined by 6-axis NC. I wanted the same results but not using NC machining. What else can be used for this?

I know its hard to imagine in the digital age but machinists have machined parts without NC for far longer than they have using NC. You could always machine the parts manually, but you will have more variation from part to part( if you are good they would be minimal though, a thousandth of an inch here or there), than you would using NC. http://www.toolingu.com/dept-150-manual-machining-training.html"

 

[pantaz]

Hi again, I am trying to solve this question and i would like to help me on this. How can i machine a part who i created it on a 3D CAD system without using NC machining? It is necessary that the part have to be accurate on dimensions etc...

First step is to generate engineering drawings. The drawings must call-out material specifications, dimensional tolerance, surface finishes, etc. For example, the description included with the image states, "The part surface was finished using sand blasting." That description neglects to point out the circular boss -- what appears to be a bearing shaft -- is not sandblasted. If left out of the engineering drawings, you would likely receive an unusable part.

 

[mikex24]

does the vacuum casting can produce that part (the wiki one on previous post) without using any machining, for example? My general question is to describe the CAE technques to produce a bolt with threads on the end of it and also an inside hole along the bolt at some length. I am not sure what the CAE techniques mean. I am thinking that describing the vacuum process to produce for that part it will be the solution to this. What are some examples of CAE techniqes which relates to a part which have to produced by vacuum casting and not machined by nc machines? (i have to produce ~40 physical prototypes). I just see a video of investment casting and it seems this is the best solution to produce my part. I have a question to this. Because i have to produce this part by a process which is a representative of the intended manufacturing process of vacuum casting, at what stage of investment casting, does the vacuum can be used?

 

[pantaz]

Given that you have not provided any specifications, I can only speculate, based on the appearance of the part in the photograph.
No, casting (investment, vacuum, or any other kind) will not provide a suitable finished part without machining.
Many of your questions about casting are addressed at http://www.metalcastingdesign.com/content/category/20/50/314/

 

[mikex24]

according to the question which given to me i have to use a representative of vacuum casting process. By what process which represents the vacuum casting can this product designed? Cheers