Right, bare with me. Noob with couple of questions.

Before I delve into research i'd love a couple points clarified to save disappointment and wasted cash.

I'm looking to use a reprap machine to create reusable moulds, what I pour into said moulds depend on the quality of the material extruded right. I cant exactly go pouring molten plastic into plastic, but what about rubber or concrete?

Secondly, i'm mathtarded, I've seen on the construction directions a lot of equations, and that's a non starter for me if I need to be able to do that. I'd like to build my own rather than buy it ready to go. Is that gonna be a problem for me?

Much love Martin.

You can build your own easily once you have tracked down the parts. The equations are easy to understand as there are step by step instructions floating around.

Bear in mind the print bed is roughly 200mm square (8 inches)

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Experimenting in 3D in New Zealand

It all goes down to nothing is for free, and you get what you pay for. no one can promise you anything but a painful learning process to get reprap working from scratch. for many people the challenge is welcome and the rewards are great...

I think this person will be better off and less frustrated purchasing a kit that is completely assembled from [www.makerbot.com] or [www.bitsfrombytes.com]

they don't want to waste time or money, and don't want to need to think about it. Actually this is the benefit of paying >15,000$ plus for a commercial 3d printer like from [www.stratasys.com]

many others on the form like the up printer [pp3dp.com] i am actually impressed by this one, and it is a market changer.

anther option this person may be interested in is [www.fabathome.com] the site is not as detailed as reprap but focus is mainly on extrusion of liquids and silicon gels.

abs, and pla are reactive to many resin mixes and temps reached by the reactions. hdpe will warp with heat reactions from concrete or resins.

if your goal is to make an original and then create a mold from that using a box mold out of silicone, then reprap has a lot to offer. but direct molds are going to be difficult. there has been lost molds created, where you vaporized the plastic , and then fill in the cavity with metal, but the original mold is lost.

I believe that when makeup artist makes a cast from a mould they line it with a substance that stops the poured in substance from sticking, if that works for moulds printed then I don't see why you couldn't use any substance in the moulds.

If you want to make molds with RepRap, and I assume you already know how to create proper 3D models for these, then it's just a matter of printing and treating them in such a way that you get the desired surface result.

Look up acetone vapor bath elsewhere on these forums. The technique involves suspending the part to be smoothed, by string, in a large coffee can or other suitable container with a lid, pouring about a tablespoon of acetone in the bottom, and heating it with a blow dryer for 30 to 90 seconds (or more).

The acetone softens the sufaces, and allows them to pull smooth. The results are often very slick. Before pouring the cast material, you will need to brush some mold release onto the inside.