Step 3: Plywood Finish Sheets

8. For this step, I used a LaserCamm rapid prototyping machine that uses a laser to cut sheets of flat material. This is where the pictures break down, since you can't really photograph the LaserCamm in action. This step can be done by hand, but thin plywood tends to chip and scar at cut edges – the laser leaves a clean, burnt edge and is also perfectly accurate. To avoid this, another sheet material such as masonite, could be used. Cut four pieces of 1/4” plywood or other suitable sheet material 17-3/4” across and 15” front-to-back. That leaves a quarter-inch of overhang to the front and back of each cushion, and 3/4” overhang on each side, which overlaps the steel frame.

9. Starting from the center instead of the sides, mark the same grid as you did on the MDF, 3” front-to-back and 3-1/4” from side-to-side.

10. Mark each piece with a number, one through four. From front-to-back, the balls will slant downwards. Starting with piece number one, which will be the bottom plate of the seat pan, use a hole-cutter bit to drill the following diameters of holes, each centered on the appropriate intersection on the drawn grid. The first row, side-to-side, should be 2-7/16” in diameter. The next row, again side-to-side, should be 2-3/8” in diameter. The following rows should be 2-5/16”, 2-1/4”, and 2-3/16”. If you want to save the time and trouble of all the contouring business, just make two pieces where all the holes are 2-7/16", and another two pieces where all the holes are 2-3/8".

11. Piece number two will be the top of the seat pan. From front to back, the rows should be 2-3/8”, 2-7/16”, 2-1/2”, 2-9/16”, and 2-5/8”.

12. Piece number three will be the back of the back cushion. From side-to-side, the balls make a U-shaped contour. This time, each column of holes will be the same diameter, instead of each row. Using a hole-cutter bit, drill a column of holes 2-3/16” in diameter on the outside two rows. On the two rows just inside, the holes should be 2-5/16”. The center column should be 2-7/16”.

13. Piece number four is the top plate of the back cushion. The two outside columns should be 2-5/8” in diameter. The two columns right inside those should be 2-1/2” in diameter. The center column should be 2-3/8”.

14. Sand, stain, and seal the pieces as desired.

The first picture shows piece number one, as denoted in the steps above, already screwed and glued to the substrate on the underside of the seat pan, and the balls sitting in there. The second photo shows the same, plus piece number two, the top of the seat pan, glued and screwed onto the top of the substrate, thus trapping the balls in place -- no glue or mechanical fasteners needed. The second photo also shows piece number three attached. You can just see the edges of the plywood behind , showing how the smaller holes make an internal ridge to retain the balls.

any issues with tennis balls wedged in you butt crack after prolonged use?
love the idea
Some new schools I've seen dont even have a wood shop class.
My old dog would've gone nuts over this...
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imagine gluing a ton (almost literally) of tennis balls together in hexagon patterns and having a chair that is comprised entirely of tennis balls. It would probably be pretty comfy too.
Hey I found this on google images... if this inspires you
lol send me a link please!
thanks! I'd completely forgotten about this idea!<br>
OMG you just gave me a great idea!!! if i do end up doing that i'll post an I'ble of it (and of course i'll give you credit :) )
ha me and my gifted class are gonna make this. any tips?
cool<a href="http://www.cinemaobzor.ru/" rel="nofollow">.</a>
This is very cool!
You can go to your local tennis arena/gym(?) and pick some up in the throw-away-your-old-tennis-balls basket. They're there for recycling so if you use them for something-- it's all good!
Scenario: Tell you're girlfriend to sit in it, when she does say ::sarcastic::"Hey! you're sitting on my balls!"::/sarcastic:: I was also thinking, instead of using two sheets of MDF put some form of mesh/fabric as backing so the balls actually conform to you're body's shape and distribute the weight. Kinda like a trampoline effect but the mesh acts as a firm buffer where the balls act like a soft buffer.
I like that idea... There's some pretty strong mesh materials on the market, nowdays.
thats AWESOME!
Great work!
What you need is a &quot;Do not fart&quot; sign to go with it, or keep a tennis racket handy :-)
okay is this chair comfortable
Almost looks painful to sit on........<br />
oooooooooo I like the black with the tennis balls =D<br />
na you just like balls<br />
im joking<br /> <br />
who's your model??? now that's a hot project!
she looks bored lol
I expected her to look far more excited about sitting in a chair.
Hahahaha<br />
Fun idea, but looks unconfortable.
It might sell to the kinky crowd. :D
Thats not me :-(
Not you in the chair or your not kinky? We can work on at least one of those. :)
Me. And you will have to find me before you un-kink me.
Un-kink? Why would I want to do that? :P
You said we could work on one of those...
I wasn't talking about un-kinking. I was talking about adding some kink. Haha
I'm all for extra added kink, though I'm sure a tennis ball chair never before surfaced in the list of ideas.
For the sports crowd ;) I'm a baseball girl myself but to be honest, neither of those choices are the balls I'm into HAHA
Actually, now, I have an AC/DC song stuck in my head... :)
Plus baseballs are hard and I'm guessing you'd want 'em a little softer.
Oh... <sub>my bad</sub><br/>
Awesome! Can't believe I didn't see it yet.
I'm reminded of the seat covers of beads cab drivers used to swear by. this idea is really a mind bender.
Still do swear by in China.
How many passes on the cutter did that take? This is awesome, good job.
looks cool wish i could try it
this seems nice,I oughtta make one

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Bio: Furniture hacker. Author of Guerilla Furniture Design, out now. Find me on Twitter and Instagram @objectguerilla.
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