3D Printing Rookie Questions (for a jointed doll)

[SazzaBee]

Hi there exerts!

I am at the start of what I hope will be an adventure in 3D printing and am seeking advice. I want to find another way to manufacture (and refine the design of) a project I’ve modelled by hand, and cast in a really laborious process in my workshop.​

The project is an articulated doll in 33 separate parts. The doll is only 14cm tall. The parts fit together by hinge joints, (based on a sphere in slices with a rod through, and ‘swivel’ where one cylinder fits into a cylindrical hole (sorry but I don’t know the tech terms for this). I’ll send a photo if you need one but don’t want an un-invited image to filter out my email You can have a look at Twelvemo on my website to see images: http://www.sarahbeare.com/page4.htm

The parts have to ‘grip’ and fit together tightly so the figure holds its poses. The material I want to use for casting needs to be strong and not brittle. It should be pale ivory, or white-ish in color. And I like the idea of clear resin, but some printers (daylight ones) don’t offer clear resin.

I like the idea of solid prints, not hollow, because the weight of the object in the hand is part of its charm. I know this will put up costs of material, but by how much? The complete figure weighs 33 grams.

I need the surface to be smooth and very highly detailed. I don’t mind applying colored or other finishes to the parts but I don’t want to have to sand or fill to smooth them.

I think I probably need an SLS / DLP system, for the high detail and smooth finish, but maybe an FDM machine would be able to do the job, if I can get the right specifications and material to print with!

A budget up to about GBP 2500 or USD 3000 might be about right. I have been offered help to fund this and need to do the research and show my esteemed patron what the options are, and be sure I get the right thing for my purposes, both in terms of the technology of the machine, the design software and the materials I can use.

I am reasonably competent and computer savvy, got my own laser cutter (Epilog) and use both MAC and PC laptops. Am currently learning the basics of Blender and Sculptris for my project, and would quite like to stick with these progras to build if I can. Will obviously want to design other things but they’ll all be pretty small in general. I’m based in the East of England.

Any advice you can give me would be very much appreciated.

[ryandir]

Just to clarify, you’d like advice regarding which printer to buy for this job? Also, you can attach images to your post here, might make things easier

[AGPrototypes]

Hi SazzaBee

I’d be happy to have a look at the parts for you, to see if it’s something I can help with.

I’m based in the south of England.

Best regards

Adam

AG Prototypes

[SazzaBee]

Thanks Adam, it’s really advice about buying a printer (what sort, size, resolution, and resins I can use) that I am after. I still have to build the design in Blender. Have started learning that but getting my own machine would sure motivate me!

[SazzaBee]

Thanks. Yes please, advice about what machines I should look at specifically. There are so many options, even within my budget range. I’ve edited the post and the pic has come up rather small but gets the idea across ok.

[cobnut]

Hi @SazzaBee did you get the advice you needed? Have you made a decision on which route to go with 3D printing (if at all)?

Jon

[SazzaBee]

Hi Jon, my thinking so far is that I want the following;

• an SLA printer, for the high resolution and smooth surfaces
• one that works with lcd light not laser light, so the machine is cheaper
• the resin is for these is also cheaper
• the choice of resin is limited but the white, cream, grey, black and green available is fine, as long as the hard, firm or flexible options do the job for me. Haven’t had the chance to handle a sample and see what it’s like yet.

There are at least a couple of choices, but if you know of any more please tell me.

• LIQUID CRYSTAL 10″ SLA 3D printer
• NOBEL 1.0

The other option might be a Formlabs SLA but that uses laser light, so is a lot more costly to buy and run though.

Any more advice would be much appreciated. I don’t want to rush this decision and I really have to get the right one!

[cobnut]

Hi @SazzaBee, SLA will certainly get you a smooth finish and can avoid some of the problems with FDM printing curved parts but it’s not only a lot more expensive to buy, it’s a lot more expensive to run, and does involve some cleaning up of the printed parts (as they’ll come out covered in the resin), so you may need sinks, chemical disposal, etc.

Modern FDM machines are able to print at a very high resolution, if the parts are oriented correctly and appropriate supports used. You might find that a good quality FDM dual printer using something like HIPS (soluble) and ABS could produce the parts practically as well as an SLA machine but at a much lower ongoing cost.

A lot depends upon what your plan is. How many of these dolls do you intend/expect to make? How many per week/month?

Don’t get me wrong, I think SLA is great technology and can produce fantastic results, but it’s not something I’d recommend for a beginner to 3D printing and it may not be necessary. You really need to eliminate FDM before going down the SLA route.

Jon

[SazzaBee]

That’s very useful info thanks.

Hmmm… I didn’t know about the washing. Could you tell me more of what it entails? I’ve got a good big workshop, with water available up in the house nearby, but not right on tap there. I don’t work in an industrial estate with chemical disposal facilities.

I am a beginner with Blender, but have a very knowledgable (uni lecturer) friend who is helping. I don’t mind some trimming, if it’s still required with the 3D printing process, but I don’t want to have to smooth the finish of every item I’m making and I do want really fine detail, like eyelash level if possible.

As to numbers, if I could sell a couple a month I’d be pretty pleased, and it’s something to aim for. I know there’s a market for what I make because it’s rather different to what else is out there in the miniatures/doll enthusiast world. In the last 4 years I have sold 20 or so, at £250, so it’s got to be possible to increase the rate!

Another advantage of the SLA printers is that they are less available where I live still. When I have learned my stuff I can offer it out as a service to go with the laser cutting services I offer.

I’m really appreciating your help here Jon, so keep it coming if you have the time!

[AGPrototypes]

Hi SazzaBee

It sounds like you’re after a higher resolution than most SLA machines, which usually build at 0.1mm layers. I doubt you’ll get the quality with FDM. I use an Envisiontec Perfactory, which has amazing quality for small detailed parts, like figurines, jewellery, etc.

A few images on my Hub.

Regards

Adam

AG Prototypes

[cobnut]

Hi @SazzaBee prints coming from an SLA machine are still covered in the uncured resin and this needs to be washed off. Rather than explaining, FormLabs have this very nice visual explanation of finishing:

https://formlabs.com/support/finishing/basic-finishing-steps/

To be honest, it looks like more work than you’d need to do in many FDM prints! I’d question @AGPrototypes assertion that SLA machines lack the definition - the Form 2 can print down to 25 microns and a good FDM printer can go down to 50 microns (and some lower still). To put this in perspective, a well made print at 50 microns is going to feel practically smooth. The Envisiontec machine is very nice, but at almost £10,000 is four times your budget and hardly practical for just starting out and with an uncertain income. According to the spec sheet it’s also got a minimum resolution of 50 microns, so the Form 2 is higher and FDM can match that.

The argument in favour of SLA in terms of them being rarer is difficult to prove. In my (albeit limited) experience, most of the orders I get demanding the highest quality don’t really need it. For example, I’ve had orders asking for 100 micron prints for objects with flat sides and surfaces and/or where the part was a draft and it’s really not necessary in those situations. SLA is a must for some objects, partly because of the difference in how the objects are actually formed and partly because it can avoid the problems with isotropy (FDM prints are usually weak in a certain direction, due to how they’re built layer by layer). SLA can produce amazing prints, but personally I wouldn’t put much weight in it being a better bet in terms of ongoing customer orders, especially (as I’m sure you would be) you’re going to give honest advice on whether that extra cost is actually necessary.

As I said before, I think you really need to eliminate FDM by a practical test; at the moment there appears to be no strong case for either technology (when considering costs, clean up, etc.) so if you can prove a good case for not using one, it leaves you with a stronger case for the other.

If you’d like to send me a sample file to print, I’ll happily do my best with FDM and send it across. While I can’t guarantee I’ll be the best FDM printer out there, it should at least give you something you can hold in your hands and look at as an example.