3D Printing Resin prototype as a regular head?

What type of resin? "Resin" is a term that simply means the liquid state of certain plastics before they are cured. To say a dolls head is made from resin is a little bit like saying a cup cake is made from batter. It's not wrong, but it doesn't tell you much about the finished item. The kind of dolls that are on topic for DoA is made out of polyurethane. What type of material does the printers you are looking at use?

 

3D printing UV resin is softer than polyurethane resin, but not so soft that it can't be used for a doll part, especially a head that doesn't really bear much tension. I printed these two on an Anycubic Photon, and they're primed and airbrushed and have been all together for about 5 months now. The one on the right does have a little "crack" in the paint/primer on the side of the neck, but it's pretty hard to notice and it happened in a spot where there has a weird layer/error in the model. They don't look or feel any different from any other airbrushed/painted resin heads.

 

Yea, a lot of people are really sloppy when choosing their words, making it uneccesarily difficult for beginners and oldies alike.

No need to appologize. In the doll making section the dolls do not have to be on topic for the rest of the forum. No head is on topic from tht start, after all. All starts out as some sort of original sculpture, either in traditional materials or in the form of computer models, but none are cast from the beginning.

By UV resin do you mean some type of acrylic?
Your heads look really cool, BTW.

 

I'm intending on printing a custom head in white using my machine and dying it to match a purchased body.

the kinds of resin you can get for a printer vary in durability, as I've learned. it's best to go off of reviews as to what prints are more sturdy or delicate with whatever resin you're looking at.

I have some 3d printed ball jointed animals, and I can tell you the ones that I used higher reviewed resin for don't feel any different from a normal bjd.

I hope this helps

 

@Lillith This is the resin that I've been using:
https://www.amazon.com/dp/B07FCLLNFY?ref_=pe_623860_70668670_dpLink&th=1

Casted dolls are made with a 2-part polyurethane resin, but resin 3D printers use a resin that hardens with UV light, like the resin that eye makers use. There are variations in hardness/brittleness for different resins, but that one is pretty similar to casted resin.

And thank you!

 

Yes. I know. And doll eyes is good exampel of why it is so important to be specific!
Some doll eyes are made using acrylic resin that is cured with UV light (often in small scale, hobby level production using nail art supplies). Other use a two part acrylic resin and others still use a two part polyurethane resin. All those eyes are "resin" eyes, but regular acrylic eyes are among the cheapest out there and polyurethane eyes among the most expensive.
The one in the link is called "photo polymer" and I don't know if that is just a way to say it is a light cure resin the same way the term "thermo plastic" is often thrown around describing any plastic that can be reshaped with heat) or if it says anything about what it actually is. The term "ABS-like" is also thrown in there, adding to the confusion as ABS is not a plastic that can be cast as a resin, as far as I know. I don't know enough about the product or 3d printers to decipher that. Can you shed some light?
"Casted resins" is not one material. There are many different plasics that can be cast in resin form, all with their own properties. One of those properies is the strength of the material, the very thing that OP asked about.

 

@Lillith I get what you mean! Sorry for not being more specific. I was referring to the "nail art" type hobby level UV resin that's become popular for crafting over the last few years. I haven't heard of that being an acrylic resin before - I thought it was an epoxy resin. Hobbyist eyes are usually made with opaque polyurethane for the whites and the clear UV resin for the domes, although some people also use mass-produced acrylic bases with the same UV resin for the domes. I don't know of the commonly used resin brands making an acrylic resin - they are all labelled either epoxy or urethane.

I do think that "photo polymer" is mostly marketing speak, as the printers themselves are called "photocuring". The "ABS-like" descriptor on that particular resin is meant to describe that it's hard and rigid like ABS plastic is, compared to other UV printing resins that have more flex.

 

I'm fairly sure both epoxy and acrylic is used for nail art. I don't know about brands, though, I've only cast two part resins myself.
If it is epoxy, unless there is some limitations specific to the 3d-printing process, I can easily see it used as a functional head, as epoxy is tough stuff when cured properly. If not, it may remain slightly soft and can deform or crack under pressure, but it should be possible to compensate for that by making the pieces thicker. Again, provided that there is nothing in the printing process itself that makes that impractical.
A few material tests before starting on the actual piece should clear that up.

Different types of plastic can be quite a djungle. I can't claim to be more than a happy hobbyist myself.
With all the fun materials becoming available to the general public, so does confusion and misinformation spread. It's one thing when hobbyists get a bit confused, that is understandable, but what really annoys me is when sellers barely give any information on the products they sell.
I don't care for pretty packaging or creatively named products, I want to know exactly what it is and I want a link to the MSDS/SDS right there on the sales page or I won't buy it.

 

@RedMoonlight Thank you! They are about 5 inches or FID (small-headed 1/4) sized. I printed them together. According to the slicer the heads used 64 g and the head caps used 25 g. I would have guessed around 100g but the measurement is probably about right. I did make one of them a lot thicker than it needed to be, especially in the cap area.