[navnav2006]

Hi

Does any one have experiance of making plaster molds for parts like this????

[esscasting]

sure. I have lots of experience in producing plaster molds and plaster mold castings. are you looking for advice on making the mold, or are you looking for a casting source?

[navnav2006]

Hi esscasting

I am looking for some information or journal or litrature which explains the process. I thought of making the mold out of plaster but now i am thinking to make it out DFS (dense fused silica) and heating it in a furnace. DFS because it has the properties required for my experiment.

I also thought of making the pattern out of ABS instead of wood.

[esscasting]

well, without knowing too much detail about your project (part geometry, quantity and tooling life) and priorities (time vs $ invested vs metallurgy requirements), it's difficult for me to provide any advice. I'm not particularly familiar with DFS, but I'm under the impression that it is used to make a semi-permanent mold which it typically done for production quantities. Depending upon part shape complexity and size, this could result in significant greater investment in tooling compared to prototype/low-volume methods like traditional sand casting or plaster mold casting.

for information on a variety of casting processes, there are several books on Amazon that are fairly cheap, my guess is they are useful for the hobbyist only. If you're experiment is for a high precision, complex-shape then, I'd recommend starting at the American Foundrymen Society, www.afsinc.com. there is a searchable library in their technical section, but I'm sure you'll have to pay considerable $.

[beone]

millions of parts like this are cast in green sand molds

[Kipper]

Forget casting...what you need is a 36 axis cnc machine...Or go with what the previous poster recommends...Simple sand casting! :KISS:

[navnav2006]

Yup its a simple casting but I need a material which could give me unidirectional solidification and more over instumentations on this mold is much complex to use sand mold.

I dont have much data regarding Plaster mold its expansion coefficients, Thermal shock absorbtion capability etc...

[johnc2309]

use lost foam casting on this it gives very nice finnish and you could machine this from foam very easy

[bbox]

Navnav2006:

What are the basic dimensions? I can't read you drawing.

We investment cast A356 in-house all the time from patterns run on our own RP machines, but we have size limitations. How many do you need and what are the tolerances? Surface finish requirements? Do they need to be x-rayed or dye penetrant inspected? Need certs?

Bill Box, Mark Two Engineering, Inc.

[Kipper]

use lost foam casting on this it gives very nice finnish and you could machine this from foam very easy

Huh...Seriously? Is "gives very nice finnish" the same as French kissing? It's OK I knew you were kidding.....You "were" kidding

[johnc2309]

well its better than sand casting, if you dip your pattern in plaster first and support it in loose sand

[plastipack]

Try plaster of paris, mixed with equal parts of powdered pumice stone, which makes a find mold for casting fusible metals. Alternatively you may use dental plaster if economical.

[pointcloud]

Well thats not to complex for a sand mold....

[Kipper]

well its better than sand casting, if you dip your pattern in plaster first and support it in loose sand

Would you accept a challenge?

You make the part with lost foam and I'll cast it in sand....Let the viewers decide the winner....You get to choose from Brass Aluminium or Copper as the metal.

Personally when going the plaster route I'll stick with wax and commercial casting plaster....btw the plaster is cheaper than the sand.

[johnc2309]

i know that sand can give a very nice finnish, i cast in sand often. but i dont need a core with foam and my patterns dont need any draft. you can glue the foam into designs or cnc mill it just like they do wax but you dont need to burnout or expensive investments to deal with. but it wont get the detail of wax. we could cast something in aluminum, its fast and easy

[Kipper]

i know that sand can give a very nice finnish, i cast in sand often. but i dont need a core with foam and my patterns dont need any draft. you can glue the foam into designs or cnc mill it just like they do wax but you dont need to burnout or expensive investments to deal with. but it wont get the detail of wax. we could cast something in aluminum, its fast and easy

Lets cast the part described in post No1 then? I'll scale it so the ID is 20mm...No draft on the pattern.

Looking forward to it

[johnc2309]

Lets cast the part described in post No1 then? I'll scale it so the ID is 20mm...No draft on the pattern.

Looking forward to it

are you talking about the elbo shaped peice. i dont have time to make that from foam, and i dont need one. i will cast something i need soon and post it

[Kipper]

are you talking about the elbo shaped peice. i dont have time to make that from foam, and i dont need one. i will cast something i need soon and post it

Oh....

[pointcloud]

I