3D Printed Slip Casting Mold Larger than the Print Bed

How can we create 3D printed slip casting molds larger than the print bed? We need to split them apart! Here I build on ways to attach 3d printed parts together to be able to pour plaster slip casting molds. The outer shell is printed in several parts and assembled together using threaded inserts and foam gasket to create a strong plaster tight seal. That is attached to an inner mold (although I had a few bugs in my software that need to be fixed!) Pour in plaster and then disassemble. Once the screws are removed the outer mold basically falls off and the inner mold can easily be removed by making very cold. Best of all, all of the 3D models needed for this are automatically generated from a simple 2d sketch using my software.
If you're interested in trying yourself, sign up here shapecastmolds...
TOOLS and MATERIALS (affiliate)
PLA+ amzn.to/3QrWnnt
M3 screws amzn.to/3qensjc
M3 threaded inserts amzn.to/3OrJl6W
Driver amzn.to/44TsHDY
Foam Gasket amzn.to/44X7IAf
Soldering Station amzn.to/3KnlBiM

[@thehydroblade]

I've learned more from your handful of videos than everything else on YT. Thanks!

[@PotterybyKent]

Awesome, thank you!

[@theabristlebroom4378]

The new mold is a thing of beauty! So satisfying when the outer mold comes apart so easily!

[@PotterybyKent]

Thanks! Yes I'm really liking this new mold system!

[@nkans]

Amazing engineering. There is a lot of work. Glad to see progress with scalability not limited to 3d printer bed. Keep it up. There is definitely lot of opportunity on how we make molds in a much easier way.

[@PotterybyKent]

Thanks a lot!

[@marksstudio]

That was a terrific video! Well done man!

[@PotterybyKent]

Thanks!

[@dianestramacchia3616]

Very impressive trouble shooting with absolute minimisation of the finished mold. Well done and very interesting.

[@PotterybyKent]

Thanks a lot!

[@Bob-Is-A-PotterNow]

One feature of the cad software I use frequently is the ability to 3D print threaded holes. I do tend to use M5 to M8 bolts, but I am able to avoid having to deal with threaded inserts. Saves a little time and money. Of course,self-tapping screws would work too.

[@PotterybyKent]

Right now the backend of this isn't using CAD software. The 3D part is scripted in python with blender right now so adding threads might be a bit tricky. (However I don't know blender well, there may be some magic functions that do it). It would be nice longer term to simplify the system for end users!

[@MadMakerWorkshop]

@@PotterybyKent use openscad to produce the STL for the threaded hole insert and stick it in blender filling your holes. My 3d wokrfolw uses both OpenScad and blender. I do "creative" bits in blender and then do anything requing precison in openScad.

[@jeffmiller9902]

I'm very interested in the mold generating software you are developing . . . if/ when you decide to make it available to try and/ or purchase let me know. You could have have something that could be very popular with potters who want to get into slip casting but (like me) have had difficulty finding molds for waht the want to produce. many of the commercial plaster mold makers are out of business or have a very limiter selection. I'd be willing to pay for a software solution designed for "us".

[@PotterybyKent]

Great! Sign up on the waitlist in the description. I'm sending out updates there every now and then with progress.

[@evanildoazevedo9612]

Muito obrigado por compartilhar conosco este conhecimento.

[@PotterybyKent]

You're welcome!

[@pamelalaborde3763]

I don’t think I can use your ShapeCast site to generate STLs for the items I want to make because they have decorative features on the outside. Is it possible to add my own STL file and then have ShapeCast create the outer wall? Also, is it just the coldness of the alcohol/ice mixture that allows you to remove the 3d bowl from the plaster, or is the alcohol a necessary component? I am thinking it might be because you want slushy ice water rather than solid ice or just really cold water. Is that it? Regardless, I am thoroughly enjoying your videos!

[@PotterybyKent]

Correct - it isn't the alcohol specifically - you want the mixture to be liquid at freezer temperatures (which is a fair bit below the freezing point of water). That lets the 3d print shrink just enough to overcome the growth in the plaster and vacuum formed. Right now, Shape Cast does not support that. It is something I'm thinking about. However most features on the surface of the pot would require a multipart mold. It is also possible I could do a custom design for you.

[@dfhdez]

The plaster molds look great. I'd add handle wells to the sides to make lifting easier.

[@PotterybyKent]

Thanks! Do you have any examples of handles that might work? They could be added but I'm not sure what might actually help given how the mold needs to be moved around.

[@dfhdez]

I imagine just hollowing out small spaces about ½ inch on either side to aid in gripping the mold.@@PotterybyKent

[@PotterybyKent]

Most of them have a pretty natural place to grab with the way the slip well flairs out. But given that this one is short it doesn't have it so it can print without supports. Once I use them some more I might make some more tweaks!

[@mrbillheineken]

great job.. I been looking into making molds this way as well. BTW Where do you get that foam tape i would always use the mold soap You can mix whit vinegar and water 50/50 to remove the soap.

[@PotterybyKent]

Thanks! I get it from amazon - there's a link in the description. I've experimented with mold soap but at this point find it's not needed for just the 3d printed molds.

[@gabriellastahl9737]

Clay question: Why are my colored slips turning to pudding when i add the Mason stain. My regular white plain casting slip is fine but when i add mason stain it seizes.

[@PotterybyKent]

My first guess would be your deflocculant. Are you using Darvan? If you are, then you can add more. If not, I'd recommend darvan.

[@gabriellastahl9737]

@@PotterybyKent we used sodium silicate. What does that do to the stain?

[@PotterybyKent]

Sodium silicate is very touchy. I know adding too much will have the opposite effect which sounds like what you're describing. Darvan is much more forgiving, which is why I use it. I'm not an expert in slip chemistry, but it sounds like you're on the edge with sodium silicate and the stain is pushing it over. And/or the stain is messing with the charge properties of the clay particles with the sodium silicate in there.

[@gabriellastahl9737]

@@PotterybyKent Thank you so much!

[@Bob-Is-A-PotterNow]

I've "upgraded" two of my priners to 0.6mm jewelled nozzles (one diamond, the other ruby). Print times are significantly reduced, and decent resolution is possible I find very functional mold prints at 0.20mm resolution, and for exterior pieces (not part of the slip cast piece) work well at 0.4mm resolution. The last printer is still a 0.4mm nozzle, though also a jewelled part for longevity (I hope). So I am able to get down to 0.07mm resolution without issue; just takes forever to print...

[@PotterybyKent]

There definitely is a huge tradeoff between resolution and print time. One thing I am thinking of testing at some point is seeing how much of the 3d printed texture really impacts finished pots. For many glazed pieces I'm guessing it might not make much difference. If so, the high resolution is probably most important for anything unglazed and maybe there are some tricks to focus the print time in just those areas.

[@Bob-Is-A-PotterNow]

@@PotterybyKent I agree regarding resolution and print texture. I have generally determined that with a 0.04mm nozzle, the finished surface with a 0.2mm resolution prints work fine with a glazed piece. I really don't see the layer lines in the finished work. Unglazed requires getting down to 0.07. But 0.05 really doesn't seem to make much improvement, and really, really impacts print time.

[@PotterybyKent]

Good to know!

[@markfriedrichsen6303]

Kent do you use waterproof foil tap or regular duct foil tape?

[@PotterybyKent]

It is foil tape - I'm not sure it's specifically waterproof but it holds back the plaster long enough. (I've since moved away from using it though)

[@DT-gun]

As someone who knows not much more than what I've seen in this video, is it possible to make the slip casting straight from the 3d print? As in no need for the the plaster mould? This is so awesome, thanks for making the video.

[@PotterybyKent]

Thanks for watching! It is not - which is why the process has several steps. In short, the plaster is porous and transfers the water from the slip to deposit the clay. If you used a 3d print, it would be just like pouring the slip into a plastic bucket and back out. You'd get a dirty bucket, but no pot.

[@diegogutierrezdtv]

BEAUTIFULY DONE

[@PotterybyKent]

Thanks!

[@paulacooke4315]

Hi Kent are these stl files available to purchase anywhere, I'm on the waiting list for the software

[@PotterybyKent]

As of right now, everything is free. There are a handful of different designs I have on the gallery page (and you might be able to access those STL files already? I forget how my code works). Otherwise, I've been moving people off the waitlist pretty regularly so you shouldn't have to wait too long. At that point you definitely can get to the STLs on the gallery as well as make your own designs!

[@paulacooke4315]

Thank you Kent, I appreciate that and just sent you a super thanks 😁

[@PotterybyKent]

Thanks so much!

[@mpiercebgtek]

Nice work. Gives me some great ideas

[@PotterybyKent]

Glad to hear it!

[@malcolm7436]

Love this series, this is so clever and something I would definitely want to try, thanks for sharing your experience. I wondered why you made a smaller bowl out of the black plastic, if the smaller one is the ideal size then after the clay shrinks it'll be even smaller no? edit: Or did you say the software scales it up to account for it?

[@PotterybyKent]

Thanks! Yes, the software automatically scales the STL files for the plaster mold. The design proof is 1:1 so you can get a sense of the form before committing to plaster.

[@Tydwhitey]

I get that the exterior doesn't need to be pretty, so the rough texture and flashing isn't a big deal. But it seems to me you would want something better for the internal displaced object, yeah? PLA printers might give you better results. They're getting super cheap and their build trays are getting up there also. I've got an older Anycubic Mono X and absolutely love it.

[@Tydwhitey]

By the way, I'm super new to all this and really like your videos. Thanks for sharing your journey with us.

[@Tydwhitey]

....aaaand I just found your video about smooth 3D printed molds. So, you can ignore my question XD

[@PotterybyKent]

Indeed! There are ways to get smoother prints. Both higher resolution prints (so wait longer) or filler primer and sander are both options.

[@susan3156]

Excellent 👍

[@PotterybyKent]

Thank you!!

[@TAYSIROMAR]

اين اجد هذا

[@PotterybyKent]

In the description

[@paulacooke4315]

Thanks

[@PotterybyKent]

You're very welcome!!!

[@witchlive5579]

🥣🫖☕🥤🤌👍

[@PotterybyKent]

🙂