V4 Product Design – Furniture
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.
@v-varella 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.
@leonheld , The testing does not have to get overly scientific. You just need to be able to repeatably and safely apply a measurable load in a way that’s meaningful to the joint you are considering. I made some suggestions in the joinery topic. https://davehakkens.nl/community/forums/topic/injected-joinery-for-modular-construction/
Your first picture in the July 15 post shows the issue you are dealing with. The beam second from the left, with the high void content will behave differently than a solid section beam and the joint evaluation could be skewed. You have several basic questions, first does the extruded material have the typical strength properties published for that plastic. Second, if you are borrowing woodworking designs, does the plastic have comparable strength properties to wood when grain orientation is accounted for. Third, if the wood equivalent joint is bonded, does your heat bonding technique create a joint as strong as the base material.
Each of these can be tested with a fairly simple compression or tension test configuration. I think you have enough shop press type frames available that this is a capability that could be set up in PPHQ. If you have any mechanical engineers joining the group, they should be familiar with the techniques.
Without a way to get quantitative data, it gets difficult for users to adopt your results without doing a lot of prototyping.
That said, thank you for your work, I really like the peg friction weld technique.
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!
Hey @ramm thanks for the contribution.. nice take on using the flexibility of the plastic, instead of cutting so much a big sheet could even be heated and bent into that form. We’re currently doing quite a bit of development with bending, perhaps we can prove your concept and inspire another workspace somewhere out there to take your design into reality 🙂
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..
@timslab , nice progress. Could you explain the right hand photo in image 1? How are the two rods anchored into the PP? That is a large void. Is the left image as extruded?
For cutting the slot, a low cost XY cross vise and an endmill or router bit in the drill press could make that easier than the chisel approach.
Hey @s2019, oh.. a large void in explanation too! haha
I’ve used barrel nuts that are commonly used in furniture. One 10mm hole allows the nut to slide into the piece which can then accept 6mm thread. I’ve used two in that case because the cavity was so large.
Yes, left is as extruded.
As for the process, I set the blade depth on the table saw to 10mm and made multiple cuts. The chisel was for fine finishing. Our in-house hand router has a set speed that just seems too high and melts the plastic, leaving a nasty finish.
I want to share with you some designs ive been working on.
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!
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