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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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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 21:48

I’m sorry, but you’re wrong.
This topic is a call for designers outside V4 to share.
And  more importantly @timslab has already answered my question.

He asked for more designer input. I asked my designer friends and contacts to help, but they ALL replied with “why are workshops allowed to make money, but we are not?”.
well, you need free designs to bundle with the machines. Fine. I can’t help with this.

what’s the problem?

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 23:17

ETSY has a summary of the intellectual property topic https://www.etsy.com/legal/policy/copyrighting-and-protecting-your-work/242644599081 . It is based on US copyright law. EU probably has different definitions. It is interesting how furniture falls into a murky area because of its utilitarian application.

03/06/2019 at 00:05


Copyright law is effectively Global, through treaties, just not enforced the same everywhere…


Furniture (or indeed any utensil) are indeed harder to grasp than e.g. literature or ‘art’.

The difference is however in the ‘design’.

Is it just meant to be functional, it’s an invention (a device to levitate thyne arse off the floor).
If it is however primarily aesthetic, not just functional, it is design, and as such copyright. An aesthetic variation on the invented utensil. You’d have the copyright over the variation, even though you might not have invented it.


Think Lego: they patented the blocks they invented. Patent expired after 20/30 years, oh sh*t.

Their little ‘man’ they however copyrighted. A lego brickhead is not just technical, it is also aesthetic (designed): copyrighted until XX years after the death of the creator.

Noticed how they are now marketing there ‘brickheads’ instead of bricks?

How a chinese factory got closed because of pirating starwars-lego, not the lego in itself?

03/06/2019 at 00:09

The Etsy summary is good – but I notice it skirts around details of the Design Patent (known as a Registered Design in other countries).

In the EU there is also Unregistrered Community Designprotection – which is shorter, but doesn’t involve the same cost as a Registered Design.

None of them are much use if you haven’t got the money to take any infringers to court. 😉

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 😉

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…



10/06/2019 at 17:02


Might seem off topic, but this reminds me a lot of techniques used to build PVC bows.

This guy has done a lot of pioneering on the subject.

So I don’t know about this specific technique, but plasticsmithing can also be used on other plastics. And yes, it is strong. The drawweights of the bows you can build this way are more than sufficient to survive any Zombie Apocalypse!

10/06/2019 at 18:13

Thanks for the reference @donald

For the upcoming week I’m going to research more in the process and see what can we learn from already used processes. Glass slumping, wood bending, plastic forming and all sort of different processes that might share some similarities in order to have a broader perspective of it.

I’ll keep updating!

10/06/2019 at 18:29

@donald , Thanks for the link…Just what I needed, another hobby rabbit hole to investigate. I did find it interesting how he picks the PVC for toughness in this video (1:45) https://www.youtube.com/watch?v=lTkNNbZk5Ms . I always thought of PVC as brittle, this may open up some options in addition to the obvious Zombie prep. Also the use of dry wall as hotbox liner is interesting. The actual specs are confusing. For example the fire rated drywall get a 3-4 hour fire rating but the manufacturer states to avoid prolonged exposure above 52 C.

10/06/2019 at 18:56


I have some of his books in Eindhoven, if you like to browse them. I could drop them by.
I’m also sure that if you contact him, he’ll be more than happy to share his skills in exchange for any info he could use. Bowyers are craftsmen, always interested in improving their skills!



The hotbox specs confusions are probably a ‘better safe than sorry’ scenario.

Our backyard bowyer is pragmatic (hey, my house didn’t burn down, it works!), while a manufacturer must off course be 100% idiot proof in their specs.

Selling these hot-boxes commercially, I don’t think so. Build your own DIY hotbox: Proof of Concept delivered!

10/06/2019 at 21:19

It was suggested I link this topic on Plastic Gridbeam here in case it might be of interest. Thanks.

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.

27/06/2019 at 12:38

i know from a popular chair maker that there are not many designs passing the needed reviews; the more critical eye is going on the joinery indeed. i guess bolts won’t do but possibly metal sleeves .. having a look around you (mcdonals, petrol stations, rest stations) gives you a good idea what sold. on the other hand, one has to be careful to copy proven designs; there is often IP involved and it can bite you back even after many years.

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!!

28/06/2019 at 11:18

Sample joinery 🙂

28/06/2019 at 11:41

i’d try simulating dynamic forces attacking the weak parts over a longer time; just to see how long this is holding up; even better chairs from wood don’t last very well; in case of a chair just keep smashing one leg on the floor … honestly; i’d skip all the attempts to make joinery from plastic; to me metal sleeves are still the best; a little more difficult to TIG weld tubing together but everyone will enjoy the outcome. there is so much stuff going to the trash because of broken plastic joinery …

28/06/2019 at 15:54

here is an excellent welder at work; possibly also a good way to start thinking to recycle cans.

28/06/2019 at 20:54

Do you plan to do any quantitative strength testing of the joints? It does not look like there is a lot of material left in the mortise part, or do you plan to heatweld the joint?

28/06/2019 at 23:08

for objects not being moved around a lot like shelfs that could do, assuming little to no dynamic forces. i could use a sh** load of these. if you can make them well interlocking (still, metal wins here), i would be also happy to build a shop table from that beams. wood or metal beams are stupid expensive, needs easily 10 m .. why they are so ugly btw… ?

28/06/2019 at 23:50

same as in the ‘bricks’ topic, would be great if you add at least some information about scope and context as well what support for the ideas is being involved. having ideas isn’t the problem. you need folks being able to get through the entire process; I know  just 1 or 2 you could relate to PP. There hasn’t been a single success story in this regards, fully documented, paper work, networking, licensing, certification, etc… nor any comment what happens to the content here posted. if it just ends up in static.v4.pp.dh.nl.pay.com it basically worth little to nothing. building up a shop is already a huge invest, keep one alive and sustainable (patreon and donations isn’t an option) is a complete new whole level and start throwing money at the complete product development and production cycle, yeah well … there are more promising things; til today we were more pumping $$ into PP than we actually got something out nor made a real next move …  far from that! in fact, one has to be kinda rich to get over 6-12 months hard core work, unpaid. plastic business isn’t exactly profitable; that’s a fact known in the industry.
i am really eager to know whether v4 is just like v3, a catalog of process documentation and immature machines and now a few more ‘ideas’ which have to be debugged and fixed on the community shoulders. if you ever worked in a professional startup/production under high pressure, you may understand. Having bots searching the entire internet around PP, there is little to no evidence that anything got ever out of the bazar; to local communities at best, more likely at -3 Euro the hour …

so please, enlighten us what v4 product design actually means to you, and what the outcome will be for the PP universe.

there are protocols, definitions as well standards to drive crowd based projects; I ‘d like to see at least some of these manifested & respected.

thanks in advance and – keep up the good work –

29/06/2019 at 01:10

here the shrink wrap variant, doesn’t affect the support material when broke, enables also easy fix. PP wise that requires a ~750W Extrusion with some addons, a 2Kw shredder, mostly semi-automatic. other than that, there are 3D prints. i guess the target audience is then well established studios or shops … I think I still have some catalogs on the subject; let me find it and check how it fits to v3 and v4 and the rest of the gang 😉

29/06/2019 at 15:36

I agree with @S2019 , Heatwelding might be the finishing touch on this kind of join.
These kind of joins come from green woodworking which is dependent on the fresh wood to ‘shrink’ as it dries out.
Short of plastic doing the same, some extra ‘convincing’ will be needed to keep the join steady.

Other joineries are also good options, but as the question was about this kind of joinery, my answers is limited to ‘yes, but weld’.

29/06/2019 at 15:43

actually hard to say not knowing the application and durability of the beams. learning a little from the past (re/up-cycle, broken joinery) shrink or metal sleeves leave the support/majority material at least intact and can be easily fixed; at least easier than a worn out joint like this which doesn’t look look well under long stress 🙂

30/06/2019 at 17:37

if you could manage making a joinery enabling cubes and rectangular objects; enough to make shelfs and an extendable work – bench (see beam addons mentioned in the ‘grid beam’ sections), we’d be definitely interested, in hope the v3 & v4 beams remain re-usable for something else. i’d order the first batch of 100 Kg right away – but please not for 10000 Euro again 😉

15/07/2019 at 12:52

As mentioned before by @michael95 we dug a bit deeper into the topic of joinery the last weeks at PPHQ. @s2019, strength testing is definitely on our agenda to generate a reliable database for future projects. Up until now, we focused on an experimental approach, as well because I’m not specifically proficient in scientific testing. So in case you have any suggestions for setup and method let me know and I’ll conduct some tests on our prototypes.

Anyways I’d like to share some of the approaches that seem promising to you, see photos attached from left to right:

Wedged mortise
works pretty well with the HDPE sheet used here, as it provides enough flexibility to get a tight pressure fit without cracking. It’s pretty important to make a small notch on the tenon’s side to prevent it from slipping through the hole and relieving the pressure. Besides that a straight forward process with jigsaw and chisel. The esthetic advantages are pretty obvious, but as well in terms of strength it’s convincing (again, quantitive data is about to follow).

15/07/2019 at 13:07

Friction weld
maybe my favorite so far and a true advantage of plastic! I extruded a very thin round profile (ø10mm) from PP to get some proper dowels. A simple pressure fit didn’t maintain at all, so heat needed to be involved. After shrinkage, the dowels got a diameter of 9.5mm, I cut them into pieces and chamfered one side with a pencil sharpener. Then I put them into a drill at highest speed and pressed it with the chamfered tip into a 7.5mm hole. Friction will melt and bond the materials together, you can even see a mixed color ring around the dowel. Make sure to let the material cool down before removing the drill from the dowel to ensureproper bonding! Then just trim of the excess (and make sure to recycle it!) and give it a smooth finish with a sharp chisel or knife.
In the second example I combined it with a mortise joint, the last example uses the same technique to join a beam and a sheet, both incredibly strong. Both for the sake of a circular economy and a better bonding make sure to use the same resin throughout all pieces!

mortise and tenon
third example is the only one made from PS and it’s another level of difficulty. The material itself is pretty strong and useful for structural parts of furniture, but machining is a hell of lot more difficult as it melts fast and sticks to the blades and bits. In terms of the joint it’s crucial to give it enough tolerance as there is no such thing as flexibility with PS. A good way is to avoid hammering the pieces together, it will result instantly in cracks. The heat gun did a good job in bonding together! In terms of strength, the torque is insane!

15/07/2019 at 13:28

To finish that series I’d like to share some insights on the postproduction of the materials. First and foremost we try to reduce it to a minimum as despite a very pedantic extraction we produce micro plastic particles (more on that to follow soon). Ideas on that so far is to use clean tools and a separate extraction for working with plastic in order to remelt the chips.

PP and HDPE work well with almost any tool and edges can be easily cleaned by shaving them with a knife. PS however is a bit more demanding. A good result was to use lowest speeds possible and cooling where possible, e.g. with a water cooled metal chop saw or spiral milling bits with compressed air cooling. In general metal tools are the right choice here, e.g. spiral drill bit instead of forstner bit.

In general I found it handy to heat up the surface to smoothen it and to get rid of discolorations from the mold.

15/07/2019 at 13:36


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