Creating molds from 3D Printing?

[navkram]

Or you can just print the mold directly with silicone.

Davo,

please tell/show printing the silicone mold. sounds interesting.

[Davo]

We've printed gaskets with RTV Silicone. We don't have a video, but I'll request one.

We are working on various fast-curing Silicones to speed the printing process - otherwise it's a slow print (waiting for each layer to set), or a sloppy print.

Our machines can print in just about any emulsifiable extrudable that is thick enough that it doesn't just run out of the tube and across the build platform. Essentially from the consistency of mayonnaise through precious metal clays. We have videos of our machines printing in clay, plasticine, plah-doh and sugru (rubber). The sugru is probably the closest consistency to RTV of anything we've filmed.

Anyway, the idea is to just print the mold, rather than printing a sample piece and then building a mold around it.

[cipher0]

I don't understand how you can use printed plastic molds and pour molten metal, etc. in them. Won't the temperature of the molten metal cause the plastic mold to melt itself?

[3dkarma]

There's an scad program you can download from thingiverse that will generate a two-part mold from your model. I've successfully used this to create something with sugru. The original designer has cast pieces with wax, Knox gelatin, Oogoo and chocolate and has made casting tips and notes on metal casting via lost PLA available.

Parametric two-part mold generator for OpenSCAD

[jzatopa]

IF you need to do a lot of molding you may want to check out this roto-mold that looks like it will be on kickstarter soon. RotoMAAK

[navkram]

IF you need to do a lot of molding you may want to check out this roto-mold that looks like it will be on kickstarter soon. RotoMAAK

thank you Jzatopa, for this link.

Being new to this forum but not new to 3d printing and mold making I did not want to make it feel I was only spamming the forum, and hopefully can contribute to this forum.

I am the creator and builder of the RotoMAAK, we have done lots of testing and prototyping to get a solid machine, we are finishing up the final info for the kickstart campaign.

this was developed out of a need that I had, a customer came to me and wanted a scale model sample of a large rotational cast plastic part to justify the change to a $80,000 mold, I printed a scale model of the part close to 12 hr print time for the first one, they past this on to their customer for the engineering department to show the salesmen what the proposed changes were going to be. once in the hands of the sales department they got the green light to make the changes. meanwhile the sales department loved the model and request 10 more "salesman" samples to allow the sales to show their customers since the actual part was the size of truck bed and it has been easier for them to sell the product if the customer can hold the part.

to reproduce 10 samples on my printer would take min. 120 hours of print time not including failed prints etc. so I made a silicon mold of the printed part and developed the rotomaak to cast hollow parts, I could have cast the part solid but that was just a waste of resin, 5 lbs of resin compared to a couple ounces.

I took the first machine to the detroit makers faire to just have sitting the running because it looks cool spinning. I got tremendous response from other makers on what niche this machine could fill. so with the support of a few key companies I proceeded to make changes and now we are very close for release.

[awerby]

Cipher, there are many things that can be poured into plastic and rubber molds that aren't too hot. Yes, most molten metals would be destructive to a plastic mold, but an indirect method can be used if one wants to produce metal parts. One of these is lost wax (assuming wax was cast in the mold). The casting is encased in an outer mold made from plaster and silica powder which is heated in a kiln until the wax is burned away, then metal is introduced into the cavity. Then the plaster is washed away, so the metal object remains. The "lost PLA" method mentioned above is a variant on this technique, with a positive PLA model used instead of a wax one.

Andrew Werby
www.computersculpture.com

[python]

excuse my english, i dont understand. Is there maybe a video of that process?

[3dkarma]

excuse my english, i dont understand. Is there maybe a video of that process?

Do you mean the mold creation process, or one of the others in the link? I'm not aware of any videos of the mold creation process, but the instructions on the thingiverse page are fairly detailed. If these aren't clear or you need further help, feel free to post your questions here or on the thingiverse page. I'm not the creator of the script, but I'll help where I can.

[python]

sorry. i didnt understand how the indirect method with wax or pla works.