Two weeks ago, Raeedah and I started building the box where we will leave all of our projects this semester! This is us with our new, finished box:

 

 

And this is how we did it:

STEPS: 

1. We first chose the wood from those available and used a tape measure or ruler to mark the lines where we wanted to cut the wood. Note, we left 1/8 inch between each measurement to account for the miter (or chop) saw’s thickness. These are the measurements used:
   1. 9 pieces of 1 x 4 lumber: 14.5 inches long
   2. 6 pieces of 1 x 4 lumber: 12 inches long
   3. 4 pieces of 2 x 2 lumber: 10 inches long
      

      Measurements made on wood to cut

2. We then used the miter saw to cut all of the pieces of wood. After that, we realized that some pieces of wood were not exactly the same length as the others, so we re-measured and marked the extra material with a ruler on some boards.
   

   Using the Miter saw to cut the wood

3. Then, we sanded the pieces in the following way:
   1. First, used the circular rotating part of the belt sander machine to remove the extra material from the marked wood.
      

      Using the circular rotating sander to remove unwanted extra material

   2. Then, we used the machine sander to sand down all of the pieces of wood on all surfaces with a sanding paper of 180.
      

      Sanding down the pieces with the machine sander

   3. After that, we hand sanded all of the surfaces with a sanding paper of 320.
   4. We then saw some splints and rough sides, so we used the belt sander to remove them, while being careful not to remove too much material.
   5. Finally, we used the machine sander again, with a 120 paper, to sand the places where the belt sander was used on.
4. After sanding, we started the assembly of the box. We used a corner clamp (which itself was clamped to the table) to put together the first of the corners from one of the three main box “layers”. The longer board went against the shorter one.
   

   Corner clamp used to hold pieces of wood together while drilling and screwing

   1. We first marked with a pencil and ruler where we wanted our screws to be in. All of the measurements for where we placed the screws can be seen in the images at the end of the “Steps” section. (The height of one set of screws (those that screw the four 2 x 2 pieces to the top and bottom boards – see step 6) were not specified, and this was estimated based on the position of the other screws as well as where the top ended for the top layer.)
   2. We used a 1/8 drill bit to make two holes on the wood. Then we counter-bore the end of the holes with a drill bit of a similar diameter as our screws, and then screwed these in. We followed this procedure for all of the screws added for the box.
      

      Drilling and placing screws

   3. We did this for all of the corners from the three main box parts and then assembled these with each other to make the three layers. We also screws a couple of two of the bottom boards screws at this stage.
5. After this, we selected a router bit that we liked (after testing on another sample of wood). We used this bit and the router to route all of the edges from the three main box parts.
   

   Raeedah routing the wood pieces

6.  We then were ready to finish assembling the box:
   1. We lined up the middle board from the three bottom boards between the other two and made measurements of where the middle was and where we wanted our screws, and marked these as well as the rest from the bottom. Before adding any screws, we also marked these for the remaining steps described below.
      

      Pencil markings for the bottom screws

   2. We finished assembling the three bottom boards to the bottom main box part. We used two screws on each short side of the box for each of the three boards and then we added an additionally two screws to join the two boards on the edges to the long sides of the board.
   3. We then joined the four 2 x 2 corner pieces to the bottom layer using screws.
   4. We used two pieces of wood of the same thickness as our boards to use as separators between the bottom and middle layer and then screwed the four 2 x 2 pieces to the middle layer as well. This procedure was repeated for the top layer.
7.  After the box was fully assembled, we sanded again:
   1. We used a machine to sand the full box with an 800 sanding paper.
   2. We saw a spot with a bigger splint-like opening so we used the belt sander to remove as much as we could.
   3. We then machined sanded again with the 800 paper.
      

      Fully assembled box, shorter side (not sure if pre- or pos- final sanding).

      

      Fully assembled box, longer side (not sure if pre- or pos- final sanding).

8.  Following this post-processing steps, we started the finishing of the box. stained the whole box with the desired color that we had chosen after trying a few out, using a brush and paper.
9. We waited for about half an hour, and then added a coating of cutting board oil. We had to coat all of the sides except one and then wait for a bit before coating the last side.
10. Finally, we covered the box with gloss protective enamel and let it to dry. This would allow for the wood surface to be sealed off.
11. That’s it! The box is done! The final dimensions of the box were:
    1. Width: 12 inches
    2. Length: 15 and 15/16 inches
    3. Height: 11.5 inches

Notes from the screw measurement pictures:

• Short side: we used ⅞-1 in to be save and make sure that we avoided the distance needed for the router (turquoise).
• Long side of box: 7/16 in from the bottom was chosen (red) because the board is 15/16 in thick, so the screwed would be a little less than half the board thickness, a bit closer to the bottom. 

Troubles and IMPROVEMENTS: 

When making the box, we faced some difficulties and identified some improvements, including the following:

• We had some difficulties when putting the initial boards together, because a pair of assembled corner boards would not match another one at exact right angles.
• We also caused some small splitting in some pieces of wood when making the counter-sinking holes. We later identified that this could mostly be avoided for this type of wood by going very slowly. A couple of times, we decided to turn the board around and repeat the hole so that the box would look better in the end.
• The turquoise measurement on the short side image above gives 7/8 to 1 in for the corner screws. This is because for the first screws, one of us used one measurement while the other one the slightly longer one. We realized that we had not been super clear with the measurement, and so for the remaining sides, we wrote them down and did this better so that we would have the same measurements.
• We also did not measure the bottom screws used for the four 2 x 2 boards properly, so these went very low through the 2 x 2 board at first and we had to redo them I believe this happened for two of the boards and then we realized and fixed it.
  

  Having to make a third hole because the lower one was too low

• Perhaps the most shocking (and kind of funny) thing that happened to us, is that instead of placing the separating wood for all of the layers first and then screwing the corner 2 x 2 boards, we first screwed the bottom, then added and screwed the middle, and then added and screwed the top. This resulted in it being super hard to fit the layers within the four corners and so we had to use some pressure, unscrew some screws a bit and screw them back in, etc. until we managed.

Cost calculation:

To calculate a total cost for the box, there were different things that were considered:

Raw materials:

• The raw materials used for this box include wood and screws.
• Screws: 26 (short side)*2 + 6 (long side)*2 = 64 screws
  • $7.48/269 pieces * 64 pieces = $1.779628253 [0] (specific type of screw used not known so used a similar looking sold online). 
• Wood:
  • 1 x 4 lumber: used 9*14.5 + 6*12 = 202.5 in long
    • Pieces of “about 1 x 4” x 96 in: $3.11 [1].
    • Total cost: 202.5 in * $3.11/96 in = $6.56015625
  • 2 x 2 lumber: 4*10 = 40 in long
    • Pieces of “about 2 x 2” x 96 in: $3.11 [2].
    • Total cost: 40 in * $3.11/96 in = $0.2125217285
• Total cost = $1.779628253 + $6.56015625 + $0.2125217285 = $8.552306232

Labor time: 682 minutes or 11 hours and 22 minutes

• To calculate labor time, we counted the total time that we spent working on the box.
• I personally chose a wage of $15/hour for this work.
• Total cost = 682 min * ($15/60 min) = $170.5 

Machine time: 75 minutes

• The cost was calculated by both counting and estimating the time spent using the different machines. However, the drilling and screwing time was not included in this calculation since it was harder to estimate since a lot of the time we were switching between this and making measurements, securing the wood to the table, etc.
• The machine time is included within the labor time so this does not increase the cost related to wage, but it does in terms of electricity. I used the electricity cost per kWh calculated for the Rice postal code in my sewing post ($0.1638695652 per kWh) (see https://engi210.blogs.rice.edu/2023/01/22/paulas-apron/). I searched for the power consumption of each device and then used an ‘electricity calculator’ to calculate the cost based on the cost per kWh [3].
• Breakdown of times:
  • • Miter/chop saw = 0.17 kWh so $0.03 total [3]. 
      • A circular saw uses between 900 and 1400 W depending on size, so used 1150 W for this category (average) [4].
    • Sanding with machine (belt sander  + circular) = 1.03 kWh so $0.17 total [3].  
      • A small belt sander uses 1000 Watts, and a disc sander 1200 W, so used 1100 W (average) for this category [4].
    • Router = 0.31 kWh so $0.05 total [3].
      • I chose a power of 2.5 HP (1864.25 Watts) based on a range given for routers [5].
• Total cost = $0.03 + $0.17 + $0.05 = $3.22

Total cost: + $170.5 + $3.22 + $8.552306232 = $ 182.27230662 or about $182.

References:

[0] https://www.lowes.com/pd/Grip-Rite-6-x-1-1-8-in-Bugle-Fine-Thread-Drywall-Screws-1-lb/4776959

[1] https://www.homedepot.com/p/1-in-x-4-in-x-8-ft-Furring-Strip-Board-687642/203461000?source=shoppingads&locale=en-US&pla&mtc=SHOPPING-CM-CML-GGL-D21-021_005_BOARDS-NA-NA-NA-SMART-NA-NA-NA-NA-NBR-NA-NA-NEW-Pmax&cm_mmc=SHOPPING-CM-CML-GGL-D21-021_005_BOARDS-NA-NA-NA-SMART-NA-NA-NA-NA-NBR-NA-NA-NEW-Pmax-71700000103283445–&gclid=CjwKCAiA0JKfBhBIEiwAPhZXD2rOJ4ZW6-KLnWs3rauE1Du9Auu6D6afLcRUYB-w7ijI13qAVIvSihoC0YoQAvD_BwE&gclsrc=aw.ds

[2] https://www.homedepot.com/p/2-in-x-2-in-x-8-ft-Furring-Strip-Board-Lumber-75800593/304600525?source=shoppingads&locale=en-US&pla&mtc=SHOPPING-CM-CML-GGL-D21-021_005_BOARDS-NA-NA-NA-SMART-NA-NA-NA-NA-NBR-NA-NA-NEW-Pmax&cm_mmc=SHOPPING-CM-CML-GGL-D21-021_005_BOARDS-NA-NA-NA-SMART-NA-NA-NA-NA-NBR-NA-NA-NEW-Pmax-71700000103283445–&gclid=CjwKCAiA0JKfBhBIEiwAPhZXDxAFSYSdaRFBMhzFIzW_Eo5FmmxKYgN9SZ_qq1MM-6bb5KpYQp30thoCZaUQAvD_BwE&gclsrc=aw.ds

[3] https://www.calculator.net/electricity-calculator.html

[4] https://unboundsolar.com/solar-information/power-table

[5] https://blog.acmetools.com/how-to-choose-a-router/#:~:text=Power%20ranges%20from%20the%20basic,a%20lower%20horsepower%20will%20suffice.