Flat Pack Chair

I’m entering a competition, “Going with the grain” http://www.design21sdn.com/challenges/15

The goal is to design something out of plywood that is cut by a CNC router. We can also use a given connector form ecosystems furniture.

I am designing this chair. It’s based on the idea of two forks coming together. When the user sits down, the spokes generally form to their body contour. The material is 1’ thick plywood so it’s not going to bend a lot. Hopefully it wont break. What do you guys think?

I still need to add the counter-sunk screw-heads in my assembly…

the good:

the cantilevered seat and back are interesting.

the bad:

that’s pretty ugly. it looks like an electric chair or a toture device.

if you want to use 1" plywood, you are going to have a LOT of cnc time to cut those out.

the hardware looks like it will slice your leg open. if you’re going to incorporate that much machine time, you might as well rabbit out the wood for flush hardware.

if you use a simple arm that connects between the back and the seat, you can reduce the thickness on the plywood and make a more efficient cantilever that wont be require to carry so much stress. a thinner plywood can be laser cut.

consider fewer tines in your forks

the lateral brace in the front/mid area is probably unnecessary.

Their called ‘tines’ .


It does look a bit like an electric chair, so I would play that up, or figure something out to work around it.

Interesting concept. However in my experience building furniture with plywood, I would caution you that it is not very strong as long thin parts. If any of the “tines” were unevenly loaded, they would most likely break.

I suppose I could add a lateral support to the back forks, so it would restrict their bend, but then I might as well close the end of the ‘tines’ and make it like a deck chair. Maybe I could try with less tines, but the more they are spaced out the more gap there is for your butt / back to rest on.

i’ve read the contest brief and i’ve done some CNC furniture using plywood and i think those tines might be ok. the contest specifies 1" appleply plywood, which off the top of my head is like 15 layer plywood so its modulous of rupture is probably high enough to be on the safe side.

looks good, though i too would see about getting those bracket dealies off of the external corners of the chair. maybe specify some rabbits in the plywood so they are flush mounted? i dunno, that could compromise the plywood in a whole other way too, hmm…

Yes, and the competition only allows us to use those 1 inch brackets, which couldn’t be sunk in because the gap in the bracket is 1 inch. Perhaps a pillow could be added to mitigate “leg scraping” , but that would destroy the aesthetic…

whoops i guess i didn’t read into the bracket constraints, nevermind that part

If you have to use these big brackets, why don’t you just move the brackets to the inside and fasten from below? Are the counter-sinks already drilled or could you specify that they go on the opposite side for these four brackets?