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V4 Product Design – Furniture

Tim Slab timslab

V4 Product Design – Furniture

21/05/2019 at 11:08

Hey people!
We are now embarking on the Product Design phase of the project. There are several ‘topics’ we are tackling and this one will be focused on Furniture design. We will share our thinking along the way and are open to your ideas and suggestions.

has created a topic about Product Development in which he speaks of the core “values” that Precious Plastic products should hold. We should strive for Precious Products to:
1. Change the perception of recycled plastic to a valuable and versatile resource.
2. Engage with new audiences by building excitement around the material.
3. Produce with techniques that encourage local high quality output.
4. Embrace the unique qualities of the material.
5. Share accessible tools that enable the community to overcome challenges.
6. Explore the world of possibilities that the machines can offer.
7. Commit to circular economy principles and not contribute to other problems in the long term.

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21/05/2019 at 11:22

With these values in mind we have put together this brief:

Design furniture or pieces of furniture with recycled plastic mainly using Sheets and/or Beams (The use of injected parts is not preferred but we are up to proposals). The materials that can be used are PP, HDPE and PS. The main goal is to help workspaces around the world to make profit with these products. 
The challenge is to make a product/products that meet the industry/market high quality standards (aesthetic and stability through repetition) without compromising the price of the end product. The material is already expensive enough so the process has to offer appropriate speed and production costs to compensate. Aesthetic and function are very important aspects.. If it doesn’t function and look good it won’t sell. 
In order to guarantee the replicability of the product around the world the product should be easy to manufacture and use accessible tools and techniques: Table saw, jigsaw, bandsaw, chisel, drill, drill press, polishing… Therefore the use of tools like: CNC milling, bending machines, planners, etc. has to be very justified or preferably avoided since they are very specific and expensive tools.

List of requirements:
1. Shift Consumers perception about plastic (from problem to value)
2. Engage with furniture makers
-Using similar equipment / techniques
-Show capabilities / versatility of the material
3. Jump from DIY to Production
-Consistency through repetition – Stable quality across same pieces. ie: Process divided by stages, Specialized Jigs etc..
4. Take advantage of the material properties
-Bending-Translucent-Good with Tolerance
-Water resistant-No polishing? (Polishing makes micro plastic and not advised for PP/HDPE)
5. Enable Workspaces to make profit
-Not everybody will have all machines
-Minimize process and steps: (making parts, assembly)
-Minimize the time of making it / Economy of time
-Minimize the amount of plastic used
6. Take into account circularity of the product
-Think about the whole life cycle
-Plastic is forever

28/05/2019 at 18:47

There were some experiments lying around, so put together some quick mockups to get a sense of visual properties. Just playing with arrangements and ideas

23/05/2019 at 15:29

Here are some new and old exploratory sketches. There are currently more of chair concepts, but we will diversify that soon. My initial thinking was that chairs are a bit more consumer friendly, but reflecting on that now, it may not be the case. You will probably notice I have an itch to use these new angle beams. I explored a bit of the potential for one or two simple moulds to produce various components / arrangements of products (chairs in the cases below.
Seeing as we are still exploring which furniture type to focus on (chair, table, lamp, coffee table, etc), it would be great to hear from you guys what you gravitate towards or what you think would sell best 🙂

22/05/2019 at 11:51

Hi, Here are some sketches on the High-End-Furniture. Basically, we are going to have Big Sheets and Beams in Version 4, therefore, the goal is to build a structure quick.

First, it is about mortise and tenon as plastic is good with tolerance (HDPE and PP). Mortise and tenon can be achieved by either Sheet or Beam but the downside is requiring a bit on hands-on skills.

Secondly, about injecting joinery parts as I was injecting plastic all day ;D. Injection parts are accurate and fast, you can make 4-5 identical parts within an hour. However, making and design of the mold are expensive and complicated as we usually use CNC aluminum in Precious Plastic Community.

Third, furniture like chairs and desks can be built by joining big-angle-beams together. Whether is it possible to make such a big-angle-beams is still a question to answer but it would be the easiest way to make.

Lastly, there is an idea to make table light, making use of the Translucent property of plastics. By casting a square tube and drilling a cylinder void, lights will pass through the four sides but not the corners. However, it is not easy to drill such a big circle.

The sketches are below. Welcome to give comments and better ideas.

15/08/2019 at 12:31

Quick update in the time that has long since past..
With the idea of creating an outdoor bench, I’ve moved into the first prototype made out of plastic to test the strength of the beams and the joinery method. This prototype is only a single seater made from the bulk plastic and scrapwood. It feels very sturdy and there is hardly any flex in the thick beams. Each leg assembly weighs just over 5kgs and I used HDPE for one assembly and PP for the other, both result in same weight but behave very different on the inside.
You can see in image 1 how the PP has cooled and left a large cavity through most of the beam, where the PE legs are far more consistant and dense. It’s also interesting to note how much more the HDPE has shrunk than the PP. The cavities in the PP meant that two rods were needed as opposed to one.
Image 2 shows the process of cutting the slot, drilling it and assembling it to the other beam. Bolts will then be used to pull the one part into the other.. this process allows for great versatility should there be any unexpected surprises inside your beam. It is also very strong if your groove tolerance is tight. Drilling the holes was also fairly straight forward taking care to mark holes properly and set the angles accordingly.
Image 3 shows the assembled peice from various angles. The surface texture differs slightly between the PP and HDPE beams, but the actual extrusion follows surprisingly similar pattern. The idea is to keep this piece relatively simple, making use of mechanical fasteners and easily available machines and tools..

24/05/2019 at 07:09


Open Source is ‘free as in Speech’, NOT ‘free as in beer’.

For open source to be ‘free as in beer’ it needs to be licensed as such.


Not many people undestand this.

Once they downloaded the (open sourced) CAD-file they don’t read the license because they assume using the design is also free.


Only listing ‘enable workshops to make profit’ just strenghtens this believe.

Also demanding the design to be CC-ed ‘free as in beer’, if only for Non Commercial use, would at least acknowledge the ownership and value of the design.

This is also why the open source machine files always include a (CC/MIT) license file.


A word of warning here:

Any design NOT specifically licensed or of which the rights are NOT specifically transfered are actually covered under regular copyright and by definition pirated(!) when you use them.

If you make money of these designs, the rightful owner of these copyrights  (the designer) could sue you for damages…


This is a serious matter, that can’t just be ignored.

So let me repeat:

Open Source is ‘free as in Speech’, NOT ‘free as in beer’.
For open source to be ‘free as in beer’ it needs to be licensed as such.

23/05/2019 at 18:32

I would like to hear of one workspace that is making a profit once reasonable salaries and payback on capital expense is accounted for…If it exists, they should post the secret.

I wonder if an application there the obvious recycled look is a great benefit would be to make recycle bins (for sidewalk collection?), maybe 100l, some frame and slat design using the V4 extruded beam techniques.

22/05/2019 at 14:56

Below are some existing pieces of furniture that highlight attributes we are looking to achieve and also to avoid.

10/06/2019 at 16:41


So we want to make good quality products that uses easy to reproduce/ interesting processes to make the output apealing for the consumer eyes.
One of the processes that I’ve been digging in since quite a while it’s Bending since it uses one of the peculiarities of the material. You cannot bend metal or wood that easily. But a bending machine it’s expensive and quite especific to consider it accessible for people. What makes us think about another way of bending. The process it’s similar to thermoforming but instead of using vacuum to shape the piece we use a simple two-sided mould that presses the piece after being heated in a conventional oven.

*A little bit of an overkill for such a simple bent but honeslty the accessability makes it worth it.


In order to proof the concept we just described we desided to test a simple stool that implies bending in order to see how does it feel the end result.
– Is it strong enough?

– Does it look good?
– How easy is it to actually make it?
– What things went wrong?

– Can we use it in other materials than just PS?
We wanted to answer all this questions before deciding this is the direction we want to follow. And if we follow it what that actually implies. How much time would we need to refine the process, what is the scalability of this specific method…



02/06/2019 at 20:00

A cabinet
A simple cabinet that could be made with variations in height and with/without doors. The two sides are cut and bent to become the structural part and the shelves (min 2 – there could be more) ‘passed through’ the sides. The idea is to avoid screws here and do all the joinery with the material itself (still not fully designed).

Both sides can be made out of 1 sheet.

The way I see it, it could be rather nice if the sides were made in speckled, multicoloured plastic, and the shelves and doors (if any) in translucent plastic, so when you put stuff in it, that changes the colour of the cabinet.

—Machines needed: 2 (sheet press & bending)
Number of pieces/parts: 5 (7 with sliding doors)
Steps: 1.Make plastic sheet, 2.cut&router (router only if sliding doors) 3.bend 4. assemble
Tools: Bandsaw or router, sander.

02/06/2019 at 18:54

Another simple idea is making a stackable stool. I’m calling it the ‘X’ stool
Initially, I thought of making it in one piece in order to avoid extra steps/parts .. however, if we want to make better use of the plastic sheet it might be better to do it in two stripes, overlapped.
Both designs are stackable by rotating 45degrees one on top of the other.
At the moment, the stool is a bit too tall (at 45cm) for the 1200 sheet once flattened… but I think we can get away with a 43cm stool and that would solve the issue.

Machines needed: 2 (sheet press & bending)
Number of pieces/parts: 1-2
Steps: 1.Make plastic sheet, 2.cut, 3.bend (4. mechanical fasteners if made of 2 parts)
Tools: Bandsaw or router, sander, (pillar drill for hole in the middle)

28/05/2019 at 11:29

Follow up for the previous post I made. I have a Pinterest board with some references I found: https://pin.it/qteyqrgqtvyryb

The reference are mainly about “joinery” and “mortise and tenon”. 


27/05/2019 at 10:02


Sorry this message is not following the Topic of profitability and open source philosophy that lately is being posted here but I have some designs I wanted to share with you.
Sorry I had no time to read all the coments and contribute in that manner but I’ll do and try to give my perspective too.
General path I’m following to design:
‘m focusing on a stool for now. Exploring different ways of making it. With sheets, with sheets + beams, only with beams… And also different ways of assembly it: screws, snap in fits or solvents (in the case of PS) After exploring several ideas I want to analize them and decide which technique will be the most accessible to reproduce by the comunity and the most profitable to invest in. Having selected that I will proceed with further iterations on the design but based on a selected range of techniques + tools and I will explore other typology options like chairs, tables or shelves.

Pic 1 – So my idea is to make a bending machine to use the properties of the material and make the structure lighter while still strong and stable. I briefly defined how many pieces will be needed and how will they be made to have an idea of how much accessible it is.

Pic 2 – Trying to reproduce same design with beams with an L shape. USing a big heated mould for the extruder and or cutting into the right shape for the legs. At this point I already decided that the stool seat should be two thick plates that helps the joinery.

Pic 3 – One idea is to weld PS plates with acetate or d-limonene to make the structure (up-left corner). But another idea that I explore (up-right corner) is to use the angle beams from @timslab to make the structre 😉



24/05/2019 at 21:16


A big difference between producing a ‘product’ and producing a ‘design’ is that the product is simply something somebody buys because they need it, however ugly it is, but a design also adds aestethics.

A designs actually helps to sell the product and as such really adds value.


A Freeconomy can also include design, but once you start talking about profit (for the workshops) it no longer is a Freeconomy, it’s capitalism/regular economy. In this my designer friends are right.


Most designers I work with are sick and tired of being treated as if their work isn’t worth anything and should just be given away or taken anyway, while others make tons of money of of their work.

Mind you, I’m not talking about simple product design, I’m talking about people whose actual work it is to invent and design new products, which they can do after a long study and/or building years of experience.

Like architecture vs brick laying.


Of course the workshops do most of the actual producing/work, no argument there, just as a machine builder adds their wages to the cost of building the machine you could build yourself at cost, they also earned their fair share of the work done.

You ‘design’ your own products, great no extra costs.

You share them with others? Fine, you get other ‘product designs’ in return.


And a couple of months later you go bankrupt because nobody wants your ugly run of the mill products, and they have already donated…twice!

(yeah yeah, I exaggerate)


Most succesful (plastic) recycling busineses (in orders of revenue) are designer based, just look around.


If you want access to that ‘wealth’, for everybody involved (also the workshops), include the possibility of royalties over designs, and let ‘the market’ decide what this royalty should be.

A simple flat fee per download (like on a stock site), a percentage once succesful (e.g. 10% of profit, so after cost (including wages)) or even just a credit as the designer could do (recognising their ownership of the design, so they can keep building their brand).


NOT allowing a royalty will just mean most designers start their own workshops, producing limited edition designs and selling them at ridiculous prices and making a pretty decent living.

With royalties they could still make this pretty decent living, but from a small percentage of the millions made within the community, sales that otherwise would not have happened…

I know most would prefer the latter.

But they still need to pay the bills.


But okay.

For this project you are looking for free (beer and speech) designs to give away with the machines. Clear.

I’m sorry I can’t help you with this (besides pointing you to the existing public domain (lot’s of cool stuff out there)), but I did try.

On the plus side: If you ever want help building a “stocksite” for plastic design, just let me know. Might have already build it by that time though 😉

24/05/2019 at 16:03

Thanks for bringing that up @donald. For the purpose of this project and these products, the designs will also be under the Creative Commons or MIT liscenses. We will make it a point to note that when they’re ready.

It’s good to have this discussion, open design is not a new concept but I think it’s still in its early stages when it comes to the sharing of hardware and products. Software development has made great use of the open design ethos, but that seems to change when it gets to physical products and machines. The sense of ownership and the amount of investment when it comes to hardware seems to make it more difficult for people to share it (Big props to those who do!).
Precious Plastic as a concept still baffels a lot of people. I’m curious to hear peoples thoughts on how one would realistically go about honoring designs that have been ‘copied’. Whether that means actual royalties, or noting from where and who the design was taken.

23/05/2019 at 18:40


the secret is…

…Epic designs by great designers…

…or ‘won’t take no for an answer’ salespersons.


I prefer the first…


23/05/2019 at 16:12

I’ve talked to some designers and I run into one small problem:

5. Enable Workspaces to make profit


Not a problem, but there’s no mention of royaties for the designers….


10% royalty on nothing is still a ‘free as in beer’ design, but once the designs are getting used ‘for profit’, the designers should also get their fair share.

Or from another perspective: their added value should be theirs to do with as they seem fit.


This way they might even attach their name/brand to the design….

01/08/2019 at 17:26

Hey Guys!    This is Ram from Patagonia.


Youre doing amazing stuff. I’ve been following

since the beggining, and if it weren’t for some things i’d be there helping you years ago!


I want to be in for designing stuff. I do furniture, houses, anything. I’m a Sacred Geometry teacher

and i try to apply that to my designs always.  I’m giving you some work-in-progress seat. I hope you

can navigate it smoothly in sketchup 2018.  I’m interested in other stuff anyway. I’m working on some geodesic dome hubs, and a fog-water retainer, like Dwarka, but far better. Food dehidrators, simple housing etc..



Tell me what you think, and count with me always!

02/06/2019 at 19:13

A stackable chair
For this one, I have tried not to use the bending technique as I understand it means building yet another machine and expertise.
I have however incorporated the ‘L’ beams that @timslab has been working on. (although it could be done without i guess).
In terms of formal language, it pretty much follows a Rietveld’s logic (the way beams attach to each other etc..).
I has quite some pieces, but they’re all really simple to make (cutting beams to a size and rectangles of pressed sheet). I think could be a cool chair to have for Precious Plastic events & the stackability is definitely a plus as it can be put away when not necessary. Also, the contrast between single coloured beams and multicoloured (or translucent!) sheet could be quite nice.

ATM I’m using 2 different sizes of beams, but this could be reduced to just one size if necessary… anyway design is in the making but you get the idea

—Machines needed: 2 (sheet press & extruder)
Number of pieces/parts: 9 (2 sheets, 7 beams)
Steps: 1.Make plastic sheet, 2.cut, 3. Extrude beam (straight), 4.Extrude L beams 5. assemble
Tools: Tablesaw or hand saw(?), sander.

02/06/2019 at 18:46

One of the ideas I have been thinking about for furniture is that of making a ‘universal LEG’ or a table leg you can later attach to a table top or build a support structure with.
Simply a stripe of plastic sheet bent to an L or U shape. Using the bend as a way to mechanically strengthen the plastic sheet.
It would require workshops to be able to produce plastic sheets & bending but you can easily make all for legs and structure from just one 1200*1200 sheet.

Machines needed: 2
Steps: 1.Make plastic sheet, 2.cut, 3.bend (unions if making a whole structure)
Tools: Bandsaw, Pilar drill, sander,

27/05/2019 at 10:04

Hey following here.

Last idea. Snap fit joinery with thick plates (or double plates). Maybe too heavy but definetely easy to make.

Let me know your thoughts about this and which is (from your perspective) the most accessible and interesting to reproduce.


21/05/2019 at 19:39

Might be interesting to look at some of the design classics that have entered the public domain, and to see if they can also be make with plastic.


An other interesting approach would be to look into (open sourced) Ikea ‘hacks’ etc.


Just thinking out loud…

21/05/2019 at 18:04

Today I did some scetches about one idea that we discussed the other day during the first brainstorming.
In the two first pictures the idea is to use beams as a corner piece / internal structure very simple, just solid triangles that could be done easily with a couple of cuts in a beam.  The rest of the parts would be made with sheets following a pattern with the hand router and attached between each other with snaping joints.

In the third picture the pieces are bent in the corners so they don’t actually need any other attachment than screwing to the structural piece.

20/08/2019 at 23:27

Here is the sketchup file.

One more thing,   long ago i designed this Fog Water Captation System.
I´d love to see it tested or prototyped. I cannot do it so, im sharing it.
I love furniture, but im most exited about this kind of things.  Please keep up
being so cool, and inspiring us all.   Timslab, thanks a lot!



28/06/2019 at 11:18

Sample joinery 🙂

28/06/2019 at 11:13

Hi all,

We’ve been working on a simple, efficient and strong method to join plastic together – in particular beams and sheets. This is a prototype jig that has been made from scrap plywood and allows us to cut a mortise into a beam or sheet with a router and a ‘template bit’. Currently, the prototype only cuts a single profile, however I’m thinking of designing a system with interchangeable profiles and angles. The ultimate goal would be to attach any beam to any other beam at a range of different angles.

Let me know if you’ve seen anything like this and if you think it would be valuable!!

27/06/2019 at 12:02

Hey guys, here’s a little update on the proj:
We’ve been exploring the directions and concepts and have concluded that it would make sense to tackle sheets and beams in separate pieces. We think this would be beneficial because exploring both sheets and beams in one piece could end up looking and feeling unpleasant.So, below are a few photo’s of the developments and explorations that we’ve made in the direction of using angled beams in a piece of furniture. In the last few days a bunch of new designers have arrived at the workspace.. (@sarahg , @niky, @leonheld, @lucytheoffcutqueen) and they will be helping push these and other concepts to their completion!
The first image is the point at which we decided to push towards something outdoor related. There has been a long debate between creating a static indoor object (like a coffee table) and a more interactive piece (like a chair). We realize that what ever we create with a fair use of beams will be heavy.. making it less pleasant to be carried around. The decision to move towards the outdoor chair was taken because it can provide a better looking alternative to current recycled outdoor furniture, it has the potential to remain in one area and it highlights some of the properties of plastic. A brief exploration of the joinery can be seen in the second image and in the third is a mockup to get an idea of the feel.

03/06/2019 at 09:08

And to bring it back on topic, here is how EUIPO defines design:

Please also note the statement about the added value of design…


Their databases are also a good source for public domain / expired registrations.

This forum and one army are covered under EU copyright law, at least as far as the EU is concerned.


: registration of designs or proofable ‘prior art’ also act as lawyer-repellent. They are mostly used to prevent you getting sued over copyright infringements.

I work with copyrights on a daily basis, have registered and unregistered (but published) designs and have even registered my own Tradename. None meant to go in the offensive, all useful to prevent having to go to court 😉

02/06/2019 at 21:56

Those are some brilliant ideas.
Again I like the modularity.
Every part an optional colour.
no piece needs to be the same!

02/06/2019 at 19:15

Some references from furniture I have been looking at…

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