how to furnish your apartment with cnc tools: part 1 - stackable aalto stools

I recently moved into a new apartment with very little furniture.
Instead of shopping crazy at Ikea, I used CNC tools at Autodesk Pier 9 to decorate my new apartment.
I don\'t have any background in furniture design and have limited CNC experience, so I am also pursuing this project as a way to learn more furniture and CNC tools in Terminal 9 Store
At the beginning, I chose the simplest furniture: a stool.
Stool is a flexible and useful item for an apartment without furniture
Obviously, you can sit on the stool.
But it can also be used as a temporary bedside table and dining table.
In this Instructable I discuss the design of the stool, the water jet cut 0.
75 \"birch plywood, polished, dyed and assembled.
Thanks: a few quick shouts: Che-
Wei and Taylor\'s singleFastener Design.
They designed a flat package.
How to make fastener stools at MIT.
Josh Myers was great in general, very helpful and showed me how to use vacuum tables and router tables.
Martin Horn provides some good advice on how to use water jet cut plywood and how to dye the plywood.
Thank you all!
I considered several aspects of the design before designing the stool: material: I decided to use 3/4 \"5-
Ply birch, a sturdy, relatively machined, cheap ($50-
60 is 4\'x 8)
There are also ready-made plywood.
CNC furniture items often use it.
Manufacturing: in this project I decided to cut the Birch layer using a water jet CNC machine.
High water jet usage-
The pressure flow of water and durian, which can be worn through almost any material.
Water jet cut 0.
The 75 \"Birch layer is almost as fast as the large laser cutting machine (
For example, Metabeam of 400 watts)
But no burn marks.
Compared to the Shopbot CNC router, the water jet operation is faster, simpler, and can cut corners with a smaller radius.
However, there are two main disadvantages of the water jet in this project: the water jet only allows contour cutting (
Cutting all the way through materials).
Therefore, there is no possible countersunk hole or 3D profile.
Secondly, the water jet is cut by materials using pomegranate and high pressure water
Both colors can stain the wood.
Assembly: Finally, I want to \"flat\" the stool\"
\"Packaging\" that allows easy shipment, assembly and disassembly of stoolsassembled.
This eliminates the glue and screws selected as fasteners.
Instead, I looked into alternative Assembly options and ended up borrowing fastening techniques from my close friend CheWei and Taylor.
They designed a stool with a long bolt on it and pressed the legs against the seat above.
Look at their design.
I designed the stool based on the classic Alva Alto.
Aalto designed a simple three-legged stackable stool by fixing the curved plywood legs on the top of the round.
I like its simple and timeless design.
I designed the stool with Autodesk Inventor.
Inventor is a parametric solid modeling tool using 2D sketches> 3D Part -
> Assembly workflow.
Design an apartment
Plywood stool fixed with one bolt, obviously I need to use the pressure (Or interference)
Fit for connecting parts.
The size of the interference joint depends on the thickness of the material, and the thickness of each piece of plywood may be slightly different.
Therefore, it is crucial to update the geometry of the CAD model according to the thickness of the actual plywood used by each stool.
One way to do this is to set a parameter for the material thickness.
Inventor uses an Excel spreadsheet to create variables that can be linked to dimensions.
I created parameters for material thickness, stool height and width.
Use these variables throughout the part to inform the size of each sketch.
You can see the final design in the picture below.
Inventor and Excel files have been uploaded and I encourage you to download and use them.
Some additional features of the design: to increase the strength, I doubled the thickness of plywood for the entire stool.
I like the thicker and stronger aesthetics. looking stool.
I also have to assemble the bolts with two layers of plywood. In Che-
Wei and Taylor designed the bolts to settle on the seat using the Shopbot CNC.
The water spray can\'t drill the sink holes on the plywood, so I designed the top layer of the seat, installed the tight fitting on the head and bottom of the hex bolt, and installed the tight fitting on the shaft diameter.
For press fit, I used the same size for the female and male sections.
For example, in order to install a 3 \"square nail into a 3\" square hole, I designed a 3 \"square nail with two dimensions that are accurate.
The wood is a bit soft and a square nail of the same size as the square hole can be comfortably placed inside.
The OMAX software has been adjusted for the kerf of the water jet, which means that the 3 \"square in CAD should produce the actual 3\" square.
I used 3/8x3. 5” hex bolt (
Something like this).
I used this bolt because it was long enough to be right around the Pier9 store.
To prepare the cutting part, I exported the necessary faces in DXF.
All inventor files can be found in the attached zip file.
I imported each DXF into the Omax layout and prepared the tool path (. ord files)
For water jet cutting.
I set the quality to equal 4 (
The quality is the highest.
Higher quality = slower cutting speed).
In retrospect, it is wise to do a small test with each quality.
Each DXF is very simple, so preparing the file is like (1)
Set quality ,(2)auto-pathing, and (3)
Set the starting point.
Then I prepared the Dock 9 OMAX water jet for the cut with a set of standard activities :(1)
Start the charging pump ,(2)
Garnet Hopper pressurized ,(3)
Load plywood into a water jet ,(4)
Fixed on the bed ,(5)
Based on xy and z coordinates ,(6)loaded the .
The ord file created by the OMAX layout ,(7)
Set the material and material thickness in OMAX Make, and (8)
Check the range of the tool path to ensure that the spray head does not touch any fasteners. The one non-
The standard thing I do when operating the water jet is to lower the water level.
In the normal operation of the water jet, in order to reduce the splash and sound, the water level will be higher than the material.
I was worried that soaking plywood in the raised water bed would change color and distort the plywood.
Instead, I cut off the plywood as the water level decreases.
Despite this precaution, the water jet sprayed water, durian and \"water jet sludge\" onto the surface of the material, causing some discoloration.
After the cut was done, I removed the spray head from the plywood and removed the pieces.
Some surfaces of the incision are quite jagged, and the incision is obviously made by several degrees (
Typical of water jet).
The surface of the plywood is discolored due to the water jet process.
I dried up the pieces on the table all night.
The pieces were dry for about 16 hours in total.
Before gluing the pieces together, I polished each piece to remove the discoloration of the surface as much as possible and smooth the aliasing of the water jet cut.
I first used a hand held rotary sander to polish the surface of the plywood.
I used the vacuum bed at the 9 Wharf woodworking workshop.
I polish each surface with low sandpaper.
Until almost all discoloration is removed (4-
6 minutes per piece)
Then follow up with high sand sandpaper.
Overall, it takes about 45 minutes to Polish 9 pieces of surface.
Next, I polish the edges of each piece to eliminate the jagged shape when the water jet is cut.
For the legs, I fixed each leg with a wooden accessory attached to the wooden workbench, and then polished each leg low with my hand
High behind sandpaper. grit paper.
Each side needs 1-
Polish for 2 minutes.
I then use a sander to polish the curved edges of the legs and seats.
Finally, in order to provide a smooth surface to the top surface of the seat, I use high-
Sand paper (400-600 grit).
To stick these pieces together, I used Titebond wood glue and many clips.
Glue has about 5 minutes of work and I used 3-
4 clips per adhesive.
I had the glue set for 20 minutes before starting the stain.
Martin at the store suggested dirty plywood with boiled flax seed oil.
I use microfibers and rags.
I had the oil dry for about an hour before assembly.
Now, for simple parts: Assembly!
I ended up using a small mallet to make sure the top of the leg was once again flush with the seat.
I was very satisfied with the results of the first stool, so I decided to make two more stools to organize the stool.
For both stools, I performed exactly the same steps except for one change.
I decided to make rounded corners on the upper and lower edges of the seat.
I filled the top and bottom edges of the seat using the router table.
I chose a router bit with a rounded radius of about half the thickness of the material (3/8” radius).
Whether it\'s a seat on the top or the bottom, I make the sides of the wood look beyond recognition.
On a seaplane. Why?
In the process of water jet cutting, the edge of the wood facing down is jagged, while the Edge facing up is smooth.
The smooth edges should be relative to the reference surface
Bearings for drill bits-
To have a smooth fillet cut.
If the workpiece is flipped, the jagged surface of the edge will rub against the bearing, resulting in jagged, uneven fillet cutting.
After scraping the surface, I started to stain the stool with sand, glue and stains.
Before dyeing, I polished the film surface of the top seat by hand. That’s it!
This project is a good introduction to 2D CNC at Pier 9.
Please keep an eye on more furniture projects using other Pier 9 tools including Shopbot CNC router and 5-Axis DMS router.