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Mould Design Community, what if…???


This topic contains 122 replies, has 39 voices, and was last updated by  Gustavo Merckel 1 year ago.

Dario Zanon dzspain

Mould Design Community, what if…???

10/05/2016 at 12:16

Hi everyone! I’m absolutely excited with the idea, it’s a great one and with a big set of tools to go on but I just find a “weak point” about all this stuff when we pretend to recycle and reuse the plastic on Dave’s machines… MOULDS!

There is nothing to do with an extruder machine without a mould… so I’m wondering how can it be fixed and it is not a simple matter.

The first “pain point” is about mould design. It is not only a matter of shape but also a question of architecture as the final product should be “nice and useful (durable)” so I want to invite everyone on a discussion about “design inteligence”. My point of view is that the “designers knowledge” should be implemented on the project and maybe to create a “Plastic’s Design Market” where any producer could buy or borrow a plastic mould design to made.

On the other hand, once there’s a mould to be made, we should talk about aluminium recycling for greensand casting or CNC milling; so there’s a need about aluminium casting techics, technical knowledge and technical skills to provide.. but also CNC machines building, stepper motors control and CNC software for mould designs making.

I think that it could be great if we find the way to merge design knowledge, mould design libraries and a mould makers list to give this project a “ready to go” state.

About mould casting, I would like to advice about how useful and efficient could be a “mould makers network”, as it is needed various requirements to produce quality moulds for long lasting use and production such as machinery, knowledge, space, and so on… maybe to arrange a regional clustering could be a must in order to maximize start-up speed and reduce production expenses to someone’s project.

Do you want to join the discussion?

Thank’s for your attention 🙂

Edit, Moved to PreciousPlastic forum

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31/05/2016 at 23:23

Hi @dzspain!

I’m glad to hear your excitement and also your enthusiasm about moulds. I have been thinking the same thing.. My partner and I have just had an injection moulder made and now we are thinking about moulds.

She plans to inject PLA into temp-resistant silicone encased in plaster, or even two-part moulds. The issue comes with attaching the bush that threads into the end of the machine’s pipe.

I am considering the machine for more general component use and am thinking of testing moulds made from wood (easier for me as a furniture maker) but would also like to get some metal moulds CNC’d.

I’d be interested to know the difference in finish of the plastic from wood and metal. I imagine metal would be smoother. However, I don’t have much CAD knowledge.

Anyhow, I’m definitely interested in your Mould Makers Network and it would certainly be useful to pool our knowledge for everyone’s benefit!


ps – where in Spain are you? We’ll be in Barcelona in a few days..

01/06/2016 at 09:40

Looks like someone has to turn a few toasters or a grill into a vacuum former.


01/06/2016 at 14:16

Hi @birdynamnam and @uaneme, thank you to join this discussion topic.

I’ve been studying the mould making, just in the theoretical level, and I agree with birdynamnam about the use of thermal resistant silicone as a possibility but I haven’t made any test at all, on the other hand, what I have seen the most of the times in the plastic production manufacturing is aluminium moulds and I guess it is about two very important things:
1. It is hard enought to guarantee a long lasting use, and
2. It can be cooled easily as it has a very high thermal conductivity (a characteristic that silicone has not)

The problem about handling the aluminium to create moulds, even by can recycling, is that you need a foundry to cast the moulds… also when we’re talking about a very low tech requirements (refractary materials, sand, coal…) maybe to produce aluminium blocks to process with a CNC machine… there’s several questions to consider as energy consuming, tools, security and facilities… nothing that can not be solved but something to consider seriously.

On the other hand, there’s a technical knowledge required to produce solid, useful and productive moulds. This knowledge is avaliable on Industrial Design’s profesionals and students and so I think that the key point is to build a Mould Designers’ community and plan how they can participate in the production profits… maybe a fee for each mould made…

In my point of view, if there is a few moulds avaliable for basic items production, it would help A LOT both the producers and designers start-up. If there is also a considerable number of mould’s manufacturers around the world, a very low fee per mould design could mean a very attractive revenue for designers and a very accesible cost for manufacturers, what means, finally a very competitive cost for final users.

I’m just wandering if my thoughts makes any sense and could be helpful for the Precious Plastic project.

By the way, I’m in Valencia but unable to move to anywhere as I’m attending some courses for professional training. Hope you enjoy Barcelona, birdynamnam, it is one of my favourites cities in Spain.

02/06/2016 at 05:46

@dzspain, @birdynamnam

how would simple clay perform for simple molds? (very basic shapes)
Is there anyone who has played with this already?

press a shape in soft clay, make it in 2 or 3 parts that can be taken apart, let it dry (or bake it), but how to connect such thing to a nozzle…

put it in a iron cylinder or box with nozzle?

unbaked clay could be made wet again and reused?

Having a few cilynders os rboxes with nozzle that gan hold clay molds would then be key so that a series can be injected in one run.

any other ideas of solutions that don’t need metal would be very interesting to me, i have no experience with this and it would be very educational to see what options are available.

If anyone comes accors a video with options then please post it here or elsewhere on the forum!

02/06/2016 at 09:55

Hi there,
I have been looking in to making moulds for a while and think a mould makers network is a great idea.
The easiest and cheapest option I have found is to post on a CNC forum like the one below and see if anyone in your area is keen to help.
Scrap aluminum engine blocks can be machined to make large moulds or a DIY furnace can be built to recycle cans into a machinable block.
Free 3D design software like easel is perfect to help make any product imaginable.
I hope this is of help.


02/06/2016 at 14:03

I believe it might be a great idea to create a mould design community, but you seem to be forgetting that these machines are intended for building and use in 3rd and 2nd world countries, where cnc-machines are not readily available, and neither is green sand-casting.

I’m currently doing a study in machine building, and moulds not made with high precision machines, are something that has been bothering me as well. BUT conventional milling machines and/or other conventional tools are available in those countries, so is wood and all that. I believe that making these moulds out of wood would help the intended user more.

designing moulds to be made with cnc or casting techniques is no problem but it would only help out users in 1st world countries, who probably can figure out these things on there own as well, because they have got more people around them who might be able to help…

Might be a good idea for a dev or mod on the forum to create a new topic-collection aimed purely on the moulds.

02/06/2016 at 20:48

Welcome @paulenglish and @redgurrillia to the topic and thank you for your help and ideas.

@uaneme, there’s a lot of tutorials and other stuff about green-sand and aluminium casting on youtube and other sites, as Paulenglish shown to us (thanks Paul, I didn’t know about . I want to suggest you to visit this guy’s channel, he’s very active on home-made casting https://youtu.be/GXSCx50LlNo.

Redgurrilia, I have no information about plastic contamination in the so called “third world” and I neither know about if Dave Hakkens was thinking precisely about this part of the world when decided to launch this project but… anyway, the so called “first world” is the main plastic consumer and consecuently the major plastic trash producer. Maybe the original idea would been focused to “under-developed countries” but there’s a lot to do in our, so called, “developed-western-first-world”.

On one hand, sand casting is a very ancient technique far beyond 60 centuries back in time, babylonians, egipcians or greeks used both in art and militar fields so I think it could be easy to keep it in use anywhere as sand, like aluminium, is one of the most common materials on Earth.

On the other hand, sand casting technique is enought to build a long lasting mould with a very low tech materials as wood, wax and others so I think it could be definetely used anywhere… also in the “western world”. The “pain-point” of the process, to me, is about the technical specifications for aluminium casting and it’s handling through the casting process. Extraction temperature or the right percentaje of flux aditives are very important for high quality aluminium production from recycling, but it has no real effect on a home-made basis production, here or there.

Finally, I guess that maybe we are making a mistake when thinking about the “third world” as “helpless”, “unable to do somethings” people. Let’s see one of many examples from Africa, for instance. As they’re, unfortunately, receiving the major of our electronical waste there’s a huge electronic components availability that they transform in amazing machines and high-tech solutions http://hackaday.com/2013/10/13/3d-printer-made-from-e-waste-in-africa/

They’re also connected to the Internet, there’s also a large number of NGOs cooperanting on the field like “Engineers without borders” http://www.isf.es/ an many many others that could link every part of the puzzle.

02/06/2016 at 21:38

What is the general consensus with coating wood moulds in a resin? Or maybe just coating the mould being used in a wax.. I can see why plastic doesn’t adhere to metals, but is there not a way to create a similar surface over wood?
This may not be ideal for injection/compression moulding, but it might work wonders for extruding over a shape.

03/06/2016 at 19:03

Thanks @timslab to join us. I have no doubt that wood could be a really useful material to build moulds but I’m not sure about its behaviour if directly used as a mould itself… Some one has tested? Could it work as a long lasting mould?

As the ignition temperature of wood is from 300ºC to up to 350ºC to soft wood or from 315ºC to 395ºC to hard wood, I guess it could work with PVC (melting starts at 160ºC), PET, PEAD, PEBD (85ºC to 130ºC), PP (150ºC), PS (85ºC) or POLIAMIDES like nilon (120ºC to 150ºC) but I’m not sure about TEFLON (260ºC).

What I don’t know is about wood-pastic adherence, as wood has a porous surface maybe it should be treated previously… but I have no idea.

I guess that mould materials could be a great question to another topic in the forum.

What about to involve industrial designers into the project?

04/06/2016 at 14:43


that’s why i thought clay may be an option,
-is easy to shape
-does not melt
-available all over the world

when left to dy instead of baking then you can recycle the caly, just add water

-shrinks when baked
-sticks to plastic
-a bit less smooth surface

So is it really an option? Is there anyone who has experience with the clay/plastic combination?

04/06/2016 at 15:03

Great idea. I think it is posible to make some sort of library. The only thing is you should just share are the plans of it. Make it so that you can read some info about it. Include a few pics from a few different angles and then if you like it you can just download the CAD file. There is free CAD software avialble so there is no problem with that part.
The best way to do this is to make a another page here under the Community tab. Make it a bit like the homepage with like the bloks of info but a bit more structured. Then if you click on it you will be guided to the page that contains all the information. A few pictures, some info about the mould and the product you can make with it. Bit like thingyvers or the libary of Sketchup.

06/06/2016 at 21:01

Found this cheaper/faster method of creating a detailed mold for injection molding, or most other plastic forming techniques for that matter:
Epoxy Mold
A hard epoxy is used for the actual mold which is housed within a stronger aluminium shell.
I’m thinking one could build a similar shell with some sheet metal and create an attachment for Dave’s injection molder.

@dzspain, yea I’m looking to test some wood with a resin coating, hoping the surface will be smooth enough (Assuming that’s what plastic requires to not adhere). I’ve read that polyurethane works with plastics though, will test that too…
and about finding some industrial designers for the project.. I’m currently in my final year of studying industrial design ^^. This project is something I’m really interested in pursuing!

07/06/2016 at 17:34

That’s nice, thank’s for your ideas!

@uaneme it is a cool sugestion the use of clay, in fact I’m thinking that maybe it could be not a great material to work under presure directly on a compresion machine as, if it’s not baked, it could peel by use, but it is really easy to work with, it’s cheap and there’s worldwide. Good point!

@n-w-b, you get it! I think that there are many designers that could find a professional career within this project, and making a big contribution to its development at the same time. I’m agree with the idea of to give designers a space to show their work to the mould builders it’s a must. What about to spread the project over the design schools and over the general population to help them find each other on the project website? Does anyone knows how this website is managed? To whom should be directed this proposal?

Welcome to the topic @timslab. I’m very trusting in the epoxi potential and wood… but also worried about how temperature could affect the mould when working arround 250ºC. Can epoxi ignites at this temperature, could it be safe to human’s breath while using? I guess that these are questions to solve on the ground by testing the materials. Good for you studying design! There’s a lot to do yet in this area! How can we involve your colleagues into the project? As designer, what do you think about the idea of a “Designers Community” and a mould designs marketplace to feed the mould makers worldwide? The idea of to receive a little payment for each mould maker could it be attractive to a designer?

Thank’s again for your feedback on this topic

07/06/2016 at 18:06

Hi again! I just find a topic about moulds, materials ans so on here About an injection molding machine and the mold maybe we can keep discussing about all that stuff there and let this topic to talk and discuss about how to create such community and how could it work.

Is it OK to everyone @birdynamnam, @uaneme, @paulenglish, @redgurrillia, @timslab, @n-w-b, @Mohee?

07/06/2016 at 18:12

There’s a large discussion about materials for moulds here molding material

08/06/2016 at 00:52

I think we need some input from area’s where there is a LOT of plastic. And what materials and what TOOLS they have available.

We can make fancy CAD designs but over there Autocad is a bit too expensive, CNC not available. Juts to name a few.

This is also why i find it a bit odd to see the designs of the machines in flippin Autocad formats.

If you want machines to be made around the world then at least release the drawings in a non restricted format. I tried to open them in FreeCAD but that didn’t work.. 🙂

Sketchup is also not very compatible.

I had some succes with .STEP files Allthough that’s also not an open file format. But at least it’s more compatible then the files that Autocad spits out.

All that aside. I think it would be nice to have a repository (hopefully in 100% compatible when it comes to CAD files)

But even better would be low-tech solutions. Analog methods to make items
How to make a mold with the least amount of tools?

Clay, Gipsum? Plaster, wood, aluminium

How much pressure is there in the injection? And how to keep that pressure under control.

What are the most common tools found globally? Drill-press, chisel, hammer, anvil, saw, …sewing machine 🙂
What other (higher tech) tools would be interesting? Metal, Welding machine,
What even more high tech? 3d printer, CNC,

08/06/2016 at 17:12

@uaneme you are definetely right! Cad files are just not enught and maybe blueprints should be added to the repository.

About tools worldwide, let me introduce the Global Village Construction Set from The Open Source Ecology group. There just amazing when talking about machines.

Many thanks to share your thoughts about CAD file limits 😉

09/06/2016 at 04:14


Would .ODF (open document format) be usable for any of this?
Or is there a better open format foe Blueprint material?

What CAD format is most compatible? STEP is best compatible between AutoCAD and FreeCAD. But i don’t know about other CAD programs. Sketchup also has horrible output when it comes to compatibility. My CAD skills are still very basic and FreeCAD is the only application that’s is actually usable to me.
Blender i also can manage but thats less intuitive when it comes to exact measurements. For more organic shapes blender seems to be the better tool.

OSE has a a nice set of machines, mainly for farming and building. There should be a project like this for smaller scale production (desktop size)

Also have a look at this
There are many interesting little machines on that list as well.

Is it possible to export the AutoCAD files as STEP? That might eventually draw in a few FreeCAD users. Then the designs can be discussed on the FreeCAD forum. etc. And the then the compatibillity from .FCStd could become an issue. And then AutoCAD users can be enlightened about how flippin annoying it is when you are forced to work with non compatible file types.

I’m currently playing with paper-pulp to get an idea about making molds in a low tech style. and it tuns out to be way more difficult then i expected.
But very educational 😀 and paperpulp is a nice material to work with.

Its a bit like plastic, but doesn’t need heat, and a lot more time for the water to evaporate.

09/06/2016 at 11:54


So heat resistant silicone definitely works, my partner has used it with in an oven melting PLA. I’ll check how high it went and the brand of silicone she used. For injecting with it, I think coating it with plaster or using some wrapping would be necessary, bicycle inner tubes for example.. let’s see, as the lack of conductivity might well be an issue.

Aluminium would be better for repeat making and with higher levels of details. This is something I am going to explore, whether directly getting a pattern maker to fabricate via cnc or sand casting. @paulenglish that technique is really cool and is another thing we want to explore. More hours in a day needed.

Getting several patterns made at one time would certainly reduce costs and allow people who don’t have direct access to such facilities to be involved and receive moulds. I will certainly post up any moulds I plan to have made before I do so to see if there is any interest.

@uaneme I think clay might not be strong enough, but it is worth exploring as it would be able to be reused if rehydrated and reworked correctly. Another option would be to use a strong plaster, this could be effectively done as two part mould around a master and also has the bonus of being able to sink a bush (which connects to the thread on the machine) directly into the plaster.

One thing that might need consideration is escape vents for air as the plastic is injected. I have asked Dave about this directly and he says he hasn’t needed to use them with his moulds, but I imagine as pieces get bigger it might be problematic.

I have test injected onto plywood (not into a mould) and certainly it sticks to it @timslab I didn’t use a release agent however, but polyurethane or a resin coating might work, the only issue being the heat of the melted plastic as it hits the mould.. @dzspain as you say, using a resin mould could end with a mess of melted resin and plastic!

@uaneme Regarding CAD and file formats, I don’t have much to offer as I use sketchup, which is fine for my needs, but as you say rubbish for exporting to relevant file types for CAD.

I also agree that to maximise our labours and recycle the most plastic possible we need input from those which plastic at their disposal but who lack the means to convert it – due to problems with moulds for example.

Fusion 360 is something I’ve played with a bit and is a great, FREE, program which may be of help..

Thanks to everyone for the links, I’m going to check them out. When I have a bit of spare time and our injection moulder is completely ready I’m going to make some tests with timber and resin-coated timber moulds. Will be sure to let you know how I get on!


09/06/2016 at 14:24


thanks great feedback! plaster and sink a bush option sounds interesting. Maybe a different techniques can be combined,

plaster part with bush to connect to the injection
Clay for parts that need less detail
heat res. silicone for detailed stuff

this way pressure forces also can be distributed a bit?
Intertube as tool is also a nice idea

maybe using a lot of clay may make clay strong enough. But it will take up a lot more space and might be impractical. but if you have clay and space in abundance then it still may be an option?

Unfortunately sketchup still does not work on Linux based OS. (or at least i can’t find an option to use it yet)
Maybe we should do a poll somehow to see what other software is being used, i’m a bit of an odd-ball i guess, i refuse to use windows and mac. And that severely limits the options. However in some area’s people simply might not have mac and windows, and use recycled computers and free software (just like me)
So i can recommend Debian Ubuntu Mint to those people. in combination with FreeCAD. FreeCAD runs great even on older hardware.

Dave, when you are at remote locations on the planet, what hardware is being used there? What kind of computers (if any) are being used? Pentium, Core2, i3?
what is available??
I mean i see you on a beach, or at a dump in rural africa, but not a single computer in sight. Still you release CAD files in a Autodesk format.

WTF? 😀

Have i missed something here?

Should we have an IT section?
How to recycle a PC and turn it into a 100% Freedom respecting CAD machine.

Or is that out of the scope of this project?

09/06/2016 at 20:04

@uaneme, about plastic waste areas… we’re in! The so called “first world” is the main plastic consumer. What’s going on arround our recycling facilities? Here in my village there’s a big company that placed the containers in the streets to collect urban waste selectively but, at the same time, there’s another little recycling company working in industrial plastic waste and recycling. They clean the materials and chop all unuseful container, what is still in good conditions are on sale.

Most of the plastics on the so called “third world” are exported from our recycling facilities that also works as waste compacters. You’re right when talking about how deploy this project THERE… but I can’t stop thinking how easy could be to implent HERE and stop waste export (electronics, plastics, chemical, nuclear… waste).

So I would like to focus on our local enviroment, (as the project itself is… what about pieces from laser iron cutting?) where there’s also tools, energy, computers and all kind of materials to start. As you can see on the picture (per country ranking of plastic ocean’s waste, notice that this is about OCEAN’S WASTE, not mainland plastic waste where the top ranking is China, India, USA, Russia, Japan, Germany, United Kingdom, Mexico, France, Spain…), this is a developed countries problem mainly. I’m totally agree about to let designed moulds in a variety of file formats and also directly drawed as traditional blueprints because not anyone who has the knowledge to make a mould should have enought computer skills to work with digital files but also because it will make the moulds more accesible to anyone, anywhere, worldwide.

That makes me think about to propose too a mould makers’ network able to feed ateliers over a wide area, I think there should be a greater number of opportunities in South America’s countries, as there’s a huge recycling activity developed by a non formally organized structure. For instance, Brazil is in the top of the list #1 aluminium cans recycler, and it’s done by thousands of individuals who collect it from the streets to get a little cash. Make the plastic waste valuable makes things goes smooth and easy.

So, to my point of view, the first step is to make people watch the plastic waste as a source of useful things, bottles (water, shampoo, detergent…) but also bags, food trays, razors, electronics covers… and the whole plastic packaging’s life style we’re living in. If I can exchange my collected plastics for anything that I need or can be useful to me… plastics will have a value, or if I get payed for its harvest.

About the use of paper, your comment makes me remember this video where a girl makes strong artisan woks with white glue, toilet paper, wheat flour, cardboard, egs, vinegar, vegetal oil and a microwave (that gives the super-strength-harder-finishing, as the girl said).

@birdynamnam, thank you so much to share your experience with us with heat-resistant silicone, I was so trusted on this material for molds development… and about your resine mold experience too!

I guess that heat-resistant silicone could not be an adequated material to crystallize plastics as fast cooling is a need but it’s nice to know that it could work with a large number of items that don’t need to cristallize. Thank you so much to share the plans of your molds. I’m planning in to go into sand casting too… I’ll tell you once I’ll get.

And thanks for the software link too!

09/06/2016 at 20:06

The picture!

10/06/2016 at 03:44

Lots of discussion about mould design, I just want to add a different perspective.

Once a good method is developed for mould design, the next issue I see is how the mould is connected to the injection machine. Currently its screwed on, this is fine for experimentation but if you actually want to produce some product to sell in an economical way you need to increase the speed at which you are injecting into the moulds. So I think some thought needs to go into making a quick release/attach method for connecting the mould to the injector. Also the time that the item is in the mould needs to be considered. I have some limited experience with injection moulding, but some things I do know is there is a certain amount of time the part needs to stay in the mould otherwise if still too soft it can deform when being pulled from the mould, it can also deform once outside of the mould if its still too soft.

So I guess the plastic needs to be heated only to the point it needs to be for a good injection so that cooling time is reduced and mould turn over is increased.

10/06/2016 at 11:12


@richoz27 here you have another video of a home-made plastic blow machine sopladora de plastico casera. Notice how fast the plastic jar is taken… it should have a cooling system and so I pointed about the benefits of aluminium for production.

10/06/2016 at 12:12

Dave, when you are at remote locations on the planet, what hardware is being used there? What kind of computers (if any) are being used? Pentium, Core2, i3?
what is available??
I mean i see you on a beach, or at a dump in rural africa, but not a single computer in sight. Still you release CAD files in a Autodesk format.

haha well @uaneme the main reason for not sharing pictures of computers is that those places don’t look very…inspiring. Obviously they have computers (windows) but old ones. We made them in Autocad because its quite an industry standard. So far most people seem to be able to open them. But we are definitely interested in a more open standard. We just don’t really know which one that should be..

11/06/2016 at 02:25

Good video to watch…

11/06/2016 at 03:17

I thought it’d be great to consolidate and organize this info on the wiki. So I added a Mold section and used most of the info found in this post. Feel free to start adding more content.


I also went ahead and started a group on Thingiverse for Precious Plastic. Not sure what the process for joining is, yet. I wish I could just make it public, but not quite sure how. Maybe you’re able to submit a join request or something. Or, hopefully it is public. Check it out at http://www.thingiverse.com/groups/precious-plastic

11/06/2016 at 20:11

Hi everyone! As @birdynamnam mentioned, we’ve build an injection moulder and today I finished the first mould that we’ll try (see pic). I’ve use heat resistant silicone rubber wrapped in plaster bandage and a strong stone plaster on the top to set the bush. I know already that the rubber will take the heat as I’ve been testing this for months in a lab oven before the injection moulder was ready. The question is now whether we’ll need to add vents, if the ‘bush set’ will be strong enough and also if we’ll get it right with the temperature and pressure.


11/06/2016 at 22:09

Yeah! You go! Congratulations @birdynamnam and @paulaortega!!!

@robksawyer, I didn’t know about the wiki 🙁 and it is fantastic to have one! Thank you so much for taking care of the knowledge in this topic!

Thank you @richoz27 for this comprehensive video! It’s very illustrative!

And thank @davehakkens to honor the topic with your participation.

By the way, I’ll start with the furnace for aluminium casting. I have some metal barrels, sand, paris gypsum, fireclay… not for the whole thing but enough for a good begining.

I’ll take some pictures tomorrow.

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