Printing a Mold with a 3D-Printer

Rtechguy · Post by **Rtechguy** » Tue Jun 26, 2018 7:51 pm

It should not be impossible to MAKE a full scale 3D printer. All you would need to do is buy a 3D print head. Build a full scale track. Write the code to allow the 3D printer to travel the track. You could control it all with a raspberry pi. I would print in wax. Once you have the full wax print, you can make a plastic or whatever mold from that positive and then melt the wax out for re-use.

neutrino · Post by **neutrino** » Tue Jun 26, 2018 7:53 pm

philpw99 wrote:Thanks everyone! This thread is very informative!

One question: after a positive head is printed, can we use laser engravers to generate those detail skin texture and wrinkles? I am a total newbie at this, but I am very interested in custom doll making.

In theory it might be possible, but I would not recommend it. First of all, those laser engravements would only be of benefit if you first sand off all the print lines from the positive print. If just a little bit of print lines are still visible, then they will be visible in the mold too. Sanding perfectly takes a lot of time and many different grades of sandpaper will be needed. Also, once you make a mistake with the laser engravement, there is basically no turning back.

Much easier is to do a casual sand to remove most of the print lines. Then make a mold of it and pour in Monster Clay. The clay positive will show some print lines but removing them is super easy. Then add the fine details with precision sculpting tools. If you make a mistake, you can fix it easily. Then make the final mold, which will show no print lines and all the fine details that you added. Don't feel so bad that the perfect clay sculpt is destroyed after making the final mold. Once you have the this final mold, you are set. You can always make an identical clay positive again using that mold if you feel sad about losing the original. But most importantly, you can make that perfect silicone cast.

Here's a nice video of making the clay positive from the first (imperfect, but geometrically accurate) mold:
https://www.youtube.com/watch?v=n-Hqzlrx2Zk

neutrino · Post by **neutrino** » Tue Jun 26, 2018 8:26 pm

Printing the eyeballs is very, very helpful too.

rubherkitty · Post by **rubherkitty** » Tue Jun 26, 2018 9:05 pm

Thanks neutrino.
I agree w/ you. Even though I do a lot of work w/ Bondo (polyester) body filler, I think they only way to get lifelike detail is clay. Trying to cut or scratch wrinkles into anything hard will probably have the cracked porcelain doll look. Depends on how much patience a person has to cut and sand, blend, etc.

I will probably buy a mannequin head I like then make a mold of that then cast a sculpt head out of monster clay.
I may also have to get the mannequin head scanned and have it 3D printed in a reduced size then go from there as I want to make dolls in the 145cm range. Another consideration is to have a expert in 3D design and printing do the head from scratch via a pic.

neutrino · Post by **neutrino** » Tue Jun 26, 2018 9:23 pm

rubherkitty wrote: I will probably buy a mannequin head I like then make a mold of that then cast a sculpt head out of monster clay.
I may also have to get the mannequin head scanned and have it 3D printed in a reduced size then go from there as I want to make dolls in the 145cm range. Another consideration is to have a expert in 3D design and printing do the head from scratch via a pic.

Good point about rescaling. That is another reason why it is a good idea to have a 3D-image of the head and then make the clay positive from that, over sculpting a clay positive from scratch. You can resize a 3D-image as much as you want (and 3D-print it as many times as you want until the size is spot on). But if you sculpt a head from scratch, no matter how beautifully, and realize that the size is wrong, you have to start all over (and then probably still not get the size right).

By the way, if you have the sculpting skills to make a new face from a mannequin prototype, then you certainly have the skills to sculpt your desired face using software. You just have to learn the steps in the software, which would only take a couple of days or so, and then the rest is the sculpting just as with clay.

rubherkitty · Post by **rubherkitty** » Tue Jun 26, 2018 10:57 pm

Yeah, I downloaded Blender and something else last fall, but am still a little overwhelmed trying to figure it all out. I watched a lot of youtube tutorials too. Maybe this winter I can try again.

Re-scaling head. One of the criteria's that TDF looks at when considering legal dolls is head to body proportion.
They prefer a smaller doll to have a proper scaled adult head to match. A person could probably fudge a 85% body and 90% head. Kind of depends what you have to start with.

Some of my doll art work.

philpw99 · Post by **philpw99** » Wed Jun 27, 2018 2:49 pm

neutrino wrote:
philpw99 wrote:Thanks everyone! This thread is very informative!

One question: after a positive head is printed, can we use laser engravers to generate those detail skin texture and wrinkles? I am a total newbie at this, but I am very interested in custom doll making.
In theory it might be possible, but I would not recommend it. First of all, those laser engravements would only be of benefit if you first sand off all the print lines from the positive print. If just a little bit of print lines are still visible, then they will be visible in the mold too. Sanding perfectly takes a lot of time and many different grades of sandpaper will be needed. Also, once you make a mistake with the laser engravement, there is basically no turning back.

Much easier is to do a casual sand to remove most of the print lines. Then make a mold of it and pour in Monster Clay. The clay positive will show some print lines but removing them is super easy. Then add the fine details with precision sculpting tools. If you make a mistake, you can fix it easily. Then make the final mold, which will show no print lines and all the fine details that you added. Don't feel so bad that the perfect clay sculpt is destroyed after making the final mold. Once you have the this final mold, you are set. You can always make an identical clay positive again using that mold if you feel sad about losing the original. But most importantly, you can make that perfect silicone cast.

Here's a nice video of making the clay positive from the first (imperfect, but geometrically accurate) mold:
https://www.youtube.com/watch?v=n-Hqzlrx2Zk

Thanks for the detail answer!! Very helpful!

neutrino · Post by **neutrino** » Wed Jun 27, 2018 5:15 pm

rubherkitty wrote:Some of my doll art work.

Very pretty face. The eyes are asymmetric, but perhaps that was your intention. That's one damn tiny nose you have there, by the way.

rubherkitty · Post by **rubherkitty** » Wed Jun 27, 2018 9:40 pm

Yes, the eyes are off, but not by me. That is a mannequin head that I fixed up for a plastic BJ Doll. I noticed how off the eyes were when I was painting the eyebrows. I've done some Bondo body and head mods on cars and dolls, but have never actually sculpted a full head yet. I made all the jewelry (except for the beaded necklace) and bra.

I'm looking at doing a partial open mouth that shows a little bit of upper teeth w/a hinged jaw skull.

Here was the base mannequin head from the sales ad and you don't notice the eyes are off! LOL
I do notice it slightly now in their pic.