[Geof]

Hi Geof

Do you want it to be a solid or just a thick wall I did mold some ball's at one time around 1.750 dia after molding they were tumbled & polished they came out to be with in .0001 no machining needed a lot of hour's in the tumbler to size them

Rather than totally hijack this thread I started my own:

http://www.cnczone.com/forums/showth...964#post543964

[plastibob]

Hi Geof

Do you want it to be a solid or just a thick wall I did mold some ball's at one time around 1.750 dia after molding they were tumbled & polished they came out to be with in .0001 no machining needed a lot of hour's in the tumbler to size them

What material did you use? Did you use nitrogen or a chemical blowing agent?

[plastibob]

for those interested in building a homemade injection molding machine: on Ebay there is a Simplamatic (you can search it) that is for sale for $600. I medical company that I worked for had a couple of them, they were pretty good for small parts, prototyping.

[burnthills]

I have a CNC machine and software to design the mold I need but would like to stay away from the high prices as I will be doing low-volume items.

Does anyone have advice on materials that can be (what I believe is called) pour-molded and baked in high temperature ovens? Industrial or home ovens would be my options.

I have an idea for a product that would be about 4" thick maximum and tapered down to about 3/8" in certain spots. There are no tight tolerances, it's more of a 3D model (like an action figure toy) than a precision mechanical part.

I'm trying to research what my possibilities are so some questions are:

1. Are there problems with having such diverse thicknesses when molding (what comes to mind is trying to cook a thick pizza together with a thin one - the thin one will heat up faster and burn if left inside for the full time)?

2. What cheap raw materials that can be molded are available? I'm only interested in pastics that have 400 F or below melting points.

3. Once I have the die made and the material to use, how hard is it to pour-mold something?

4. What are safe ways to dye the plastic if it is purchased in white/black/clear colors?

If anyone out there has good references for me to read or has experience with pouring molds, I'd very much appreciate hearing from you. This is not a business idea for profit but more for hobby and making some things for friends as gifts.

Thanks!
You can email me direct burnthills at gmail dot com.

[airpro_1]

Try looking at this web page sounds like what you might need. I have seen demos of this product at several tradeshows and can vouch for how easy it is to make a mold and make parts.

Smooth-On, Inc. - Mold Making & Casting Materials Rubber, Plastic, Lifecasting, and More

Good Luck!

[jimmy111]

Try looking at this web page sounds like what you might need. I have seen demos of this product at several tradeshows and can vouch for how easy it is to make a mold and make parts.

Smooth-On, Inc. - Mold Making & Casting Materials Rubber, Plastic, Lifecasting, and More

Good Luck!

It is ok however quite expensive.

[billt681]

gun powder is also explosive and people use it every day....we do things in our daily lives that are possibly dangerous ,use chainsaws,grinders,ect but we still do it because thats what we choose to do in our past time, we take the safety into concideration and build things at our own risk and liability

[nighthowler]

I have actually just finished building a homemade benchtop plastic injection molding machine, based on a small picture I found on the internet.
The total cost of the build was £200, but my next project is to find the best product I could use to make moulds that can be used to inject molten pastic into and withstand temperatures up to 300 degs C at the injector nozzel, because the cost of buying steel or aluminium and then not having access or the expertise to use a CNC or Milling Machine and having to have someone make the moulds I require is a ridicules amount of money.
So if anybody has any ideas of a heat resistant product or who can make fairly cheap two part moulds that can be used for injection molding please contact me. ( [email protected] )
Also has anybody any advice on the best nozzel size to use

[Rob_M.]

I have actually sort of gave up on the idea for the moment, actually years ago. I ended up getting a CNC Machine and have opened up my own little shop. So if anyone is looking for some molds to be made let me know.

[mactec54]

Rob_M.

You should post some photos of the molds & what you make, this would create more interest

[nighthowler]

I have posted the pictures of the machine I made

[mactec54]

nighthowler

My reply was to Rob_M. said in his post

[jimmy111]

I make molds. It is a tough business. If you cant also heat treat and polish them you will be in big trouble. The polishing cost more in time and materials than the mold itself.

[Rob_M.]

Rob_M.

You should post some photos of the molds & what you make, this would create more interest

The last real injection mold I made was several years ago. It's actually at an injection molding shop in new york, I haven't seen it since. I do have some molds that I made that I used to just pour silicone into, let cure, then take apart. They aren't very sophisticated but they made a nice part.

[nighthowler]

I will take some pictures of the parts that I need someone to make the Molds for and post them asap, please forgiveme for not thinking i would get much if any responce.
I will be truely gratefully for any help in my quest

[nighthowler]

These are the type of parts I am hoping to replicate with my plastic molding machine.
These picture were taken from the internet but are a true representation of just a few of the parts I am looking to have molds made for.
I have no idea where to start giving the true measurments (dimensions) of these parts, all I can say is that they are spare parts for a small model radio controlled helicoptor.