Starting off this week I had some ideas but I wanted to do something that moves.
After doing some initial research online I found someone in the past years who made an
adjustable table
that I thought was awesome, although I wanted to add my own spin to it. So instead of a table I am going to make
a laptop stand and instead of having 1 degree of freedom I decided to add a second degree of freedom for the angle of the stand.
I started this week like I have started the other CAD weeks, by trying to sketch each part individually. That was starting to work
but I got to a stage where I did not know how to create on CAD, the steps for the degrees of freedom. I went to Alfonso for help and
he instructed me to restart but model it in 3D. So with that I started.
I made the first design in 3d not caring about what it looks like. While building I started parameterizing so that if there was anything I needed
to change I could do that easily. I started by building my first piece and I tried to do it with as many key binds as possibe. I learned that shift
two finger on the track pad moves around easily so I used that as much as possible. I also learned that by typing s I was able to bring up a menu
where I could type any action and it would bring it up. My goal was to use as little effort as possible so I decided to make each piece one time then
mirror it across a midplane I constructed. One of the biggest things I used was the projection function. This helped me make the model in 3D.
The projection function allowed me to see what the layer I was building on looked like and specifically what measurements I used. I then used the
extrusion function and extruded from a plane to an object which was a function that I didn't know existed. I made a bunch of mistakes with making new
bodies versus joining. One problem I had was that I was joining the wrong bodies. Another function I used for the first time was the circular repeat.
To make the holes for the top adjuster I wanted to be able to lock into an angle. So I made a triangle and rotated it and copied it on a 25% angle.
After that first iteration I was not very happy with what it looked like. So I decided I was going to re-model it and make it look as pretty as possible.
In the end it turned into something I was legitimetly proud of. This time I also measured out exactly how tall each piece would be. I really don't
understand millimeters and I didn't have a ruler so I was using relative things to measure and approximate heights. This was a fun part be cause I got
pretty creative. Once I finished I was able to sit back and bask in the beauty of my creation. This was the first time in this class I really proud of something
I made and it was because I spent so much time thinking about it and it ended up being almost exactly like I imagined.
Cutting out the wood was the next part. In order to mill each piece I needed to get the DXF each piece. To do this I projected the pieces and then saved that as
a DXF file. For the peices which I was making a pocket instead of a hole, I needed to make sure that I projected the pocket part as well as the entire edge so that I
can seperate them in Aspire, the software to make the G-Code. I was following Nathan's SOP. After uploading to Aspire, I made sure to dogbone the inner corners.
I needed to choose the order which to perform the cuts. I decided to do the pockets first then the inside holes then the outside holes. I needed to make the g-code
for each in that order because the shopbot takes in the code and does it in order so I wanted the inside pieces done before I cut out the entire shape. Even though I
was adding tabs to make the shapes not fly out of the wood I wanted to make sure the insides where done before there could be any issues. After highlighting each piece
I wanted to make a pocket of, I went in and changed the mill to the 1/8th inch drill bit we were using, slowed down the speed of the movement and kept the same spin
speed of the CNC per Leo's chipping calculator on his website. I then set the depth it was going to drill into the wood, I set that at .6 the height of the wood. Then I hit calculate.
Then I did the inside holes. For this I selected holes, same drill bit, inside cut and climb (compared to conventional). I added tabs to any insdie peice that was too large.
Then I hit calculate. Then I redid most of the steps for the outlines but instead of inside cutting I selected outside cutting. And I made sure to put enough tabs and put the tabs on
straight areas. Since I was using the small shop bot the wood pieces were 24 in by 18 in and they had taken the polymer nails to the shop downstairs so I used a drill to drill in
the wood peices to the sacrifical base layer. Don't put the power drill to drill backwards it will not drill in. I turned the machine on by flipping the switch,
then I zerod the CNC machine at the corner and took the key and ran a air cut. After I made sure the drill would not hit the screws I zerod the mill to the wood
and ran the Aspire file. In one of my runs I should have drilled nails in the middle as well because the wood was lifting up in the middle and it made the cut suffer.
I used the small shop bot so I cut three pieces of wood to get all of my pieces milled.
A couple stupid things I did in this step. I only saved one side of each of my pieces and at first I cut them as direct duplicates as one another. But while trying to assemble
I realized that I actually needed the inverse pairs. I also set the width of some of my holes incorrectly because I did not measure the wood before hand.
After I cut out all the pieces I tried fitting them together and the holes we slightly too small to fit, i think because I made them the exact same size, which
I thought would be ok but I ended up having to sand all the peices down just a little to make them all fit. In order to get the movement mechanisms to work and to fit all
the peices together I used dowels that I had measured before hand and added into my design. These allowed the parts that need to move a path.
In the end I was extremely satisfied with the work that I did this week. A couple future additions I would try to get better wood, I would varnish the wood for longevity,
and I would change the sizes of the holes for a more seamless fit.
