16. Wildcard Week¶
Task: Wildcard Week Design and produce something with a digital process (incorporating computer aided design and manufacturing) not covered in another assignment, documenting the requirements that your assignment meets, and including everything necessary to reproduce it. Possibilities include but are not limited to wildcard week examples.
I did other trial based on digital process in my NDA folder for the next generation seat.¶
Research¶
I am designing next version of FABLAB.able Seat with half bamboo material such as swinging frame parts.
These parts are currently made of CNC milled Plywood and assembled with Glue.
Since it takes time to operate CNC for all parts from 2 and a half board of plywoods, I wanted to develop half handmade manufacturing method for Global South FABLAB such as Kenyan FABLAB Winam.
It might also solve the high unemployment ratio of young people there.
Bamboo bending for Designed shape¶
I wrote the design of my developing seat in NDA folder due to it’s confidentiality.
Trial of Tube Bamboo bending¶
I visited bamboo forest near my house by asking the forest land owner to cut several pieces.
In Japan, Bamboo forest is everywhere, and they are spreading dramatically.
In the following situation is very common in those bamboo forest, that grown bamboo make the forest very dense and they can no more get enough sun light to maintain themselves so that the forest will die not growing anything whatsoever…
I chose some young bamboo (year 1.5 to 2 years old) for the seat frame parts.
Cut some of them.
Brought them in my car.
Firstly, I tried Tube bamboo (diameter 37mm) using shaft and burner (fire) by installing sand in side of the tube.
Cracks were happening around 20-30 degree bending.
This angle must be the limit for this method.
Did several trial.
Still 30 degree bend is the limit…
Then, I decided to go for stripping them into thin layers and bend and laminated with glue.¶
Trial of Stripped Bamboo bending¶
Visited the bamboo forest for getting the thicker bamboo such as more than 80 to 100mm as diameter.
Chose thicker bamboo.
Cut them for then next trial.
Prepare Borax and Boric Acid for the treatment.
Make 10% of Borax and Boric Acid (same amount for both) combined water.
Pour the 10% of Boric Acid and Borax water into Bamboo Tube.
Tape them and keep for a week.
Small piece were prepared for the Youngs Modulus Test.
Stripping them.
Stripping them until around 5mm thickness.
Designed and made molds for bamboo bending in Toyota.
Iron Mold were chosen this time for possible burner bending.
Putting wood blue on the surface of stripped bamboo to laminate.
But it was too hard to bend both bamboo at the same time…
I had to go for one bamboo bending at a time…
Setting stripped bamboo between the mold with ratchet belt system.
Gradually pulling ratchet belt by heating the stripped bamboo with heat gun.
Pouring hot water helps bending.
First Bending Trial
Result of the first bending trial
For the 2nd trial, I placed them a night in the water.
]
2nd bamboo bending with clamps
Then added one more layer of stripped bamboo with glue to compressing.
composite trial with bent wood¶
I wanted to try the composite manufacturing trial with bent bamboo and wood to reinforce.
I visited local furniture maker who produces Bio based fast epoxy resin.
They were making an objet d’art with epoxy.
This table was made by reinforcing used wood box from Harley Davidson transportation with epoxy.
Beautiful table with epoxy reinforcement
I purchased their “Bio Fast Resin” for my composite trial.
A liquid : B liquid = 2 : 1
Takes 30 minutes to start heating and getting hard.
Mixing amount for both A and B liquid
I tried with 100g as a total at first.
Pouring A liquid for 67g
Pouring B liquid into A until total weight gets 100g.
Putting two layers of linen on the surface of the bent wood.
Having a strong recommendation and warning by Rico whom I followed about the composite trial in his FAB Academy Wild Card,
I worked at the exhaust gas vacuuming system in our facility (Toyota Technical Center) just in case.
Painting resin on the surface of bent wood with brush.
I found it very difficult to place linen following the steep curve with resin…
Then, I had to tye at the sharp corner…
Which might spoil the appearance…
It was difficult to get special Vacuuming Bag for composite process, so I purchased Futon Vacuuming Bag instead at the DIY shop.
It says the material of Futon Vacuuming Bag is PE and Nylon.
Result after 2 days of fixing
I had been worrying about vacuuming plastic bag (PE and Nylon) might be firmly fixed against the epoxy surface, but it didn’t.
The surface seems like vinyl by exactly copying the vacuuming bag surface.
The vinyl strap also easy to remove.
Measurement of Epoxy reinforcement stiffness¶
Here is the measurement tools for the bending reaction force measurement;
laser displacement sensor
force gage
* belt
* bar fro applying force manually
The result of Bio Fast Resin epoxy reinforcement
It shows 1.8 times stiffer than without epoxy.
Having not enough time to go for the additional opposite side layer epoxy fixation with linen, the result was not that hard as I imagined.
I should try the both side covering later, but I would get rid of the side covering by linen which is very difficult to make the smooth surface.
Considering the aesthetics, I have to design proper molding with breathing fabric with compression force in addition to the vacuuming force.