Week 7: Computer Controlled Machining

1. First, I changed the document units to CGS and created a center point rectange of 87X35 cmin the top plane.

2. Then, using the sketch fillet in all the corners I made arcs of 5 cm.

3.After that, I made large finger joint for the lateral faces. For that, I drew a rectangle at the border of 19.5 X mw(1.2 cm) at a distance of 12 cm from the side and center. Then I used the mirror tool to replicate it in both, the opposite side and opposite face. These joints are this thick because they will be joined to the side faces, which are mw thick.

4. Then, I made a rectangle of 2mw X 12 cm at a distance of 2.5 cm from the top border and 5 cm from the side. After that, I used the mirror tool for the 3 columns I planned my box to have. Each wall will consist of two identical pieces of mw thick.

5. Finally I extruded my piece and the cuts.

1. First, I changed the document units to CGS and created a center point rectange of 87X33 cmin the front plane.

2. Then, using the sketch fillet in all the corners I made arcs of 5 cm.

3.After that, I followed a similar process to the one for the base. First I made the holes for the columns or interior walls at the same distance as I did in the base, because it was crucial for them to fit on both sides, the base and the sides.

Then, I made center point rectangle at a distance of 10 cm from the left side and 6 cm from the center. Subsequently, I used the sketch fillet tool and made arcs of 5 cm in all the corners of that rectangle. Finally, I used the mirror tool and duplicate it in the opposite side.

This gates will be used to store my dumbells.

4. Then, I made a rectangle of 19.5 X mw at a distance of 12 cm from the side and center. After that, I used the mirror tool for duplicate it in the other side. These rectangles will be to join this side face to the base.

5. Finally I extruded my piece and the cuts.

1. First, I changed the document units to CGS and created a center point rectange of 33 X 35 cmin the front plane.

2. Then, I made two rectangles at the top and left border and mirror them.

3. All of the joints have a height of mw with the exception of the top ones, those have a height of 2 mw because in the top will be two layers, each of mw. Each finger joint has a width of 12 cm.

In the sides, the distance between the finger joints and the bottom is of 2 cm. In the top, the distance between the joints and the sides of the rectangle is of 2.5 cm.

4. Then, I made a circle of 0.78 cm of diameter at a distance of 15 cm vertically and 13 cm horizontally from the center. After that, I used the mirror tool for duplicate it in the other side and down. These holes will be for M8 screws that will connect the two pieces I’ll have for each column.

5. Finally I extruded my piece and the cuts.

1. First, I changed the document units to CGS and created a center point rectange of 35 X 87 cmin the front plane.

2. Then, using the sketch fillet in all the corners I made arcs of 5 cm.

3. Then I made the same holes of 2mw width, I did in the base.

4. Then, I made a circle of 0.78 cm of diameter at a distance of 12.5 cm vertically and 34 cm horizontally from the center. After that, I used the mirror tool for duplicate it in the other side and down. These holes will be for M8 screws that will connect the two pieces I’ll have for each column.

5. Finally I extruded my piece and the cuts.

1. First we have to click on File, located at the left top corner, and select save as in the menu.

2. Then we have to click on the Document type tab, look for DXF and select it.

3. After that a lateral menu will deploy and there we can choose the plane where our pice will be saved in the DXF document.

4. Finally a preview of our document will be shown. After that just have to save it.

1. First we have to open VCarve and create a new file. In the left menu is a list where we must select the first option.

2. Then, a workspace will pop up and in the left side we can choose the characteristics of our board and where to set the origin point.

3. Then we have to click on FILE and Import. Later, we have to choose te file we want to import, in my case here are my 4 pieces.

4. Then we have to add our pieces and placing them in the board. At the corner of each piece is a symbol to rotate the figure.

5. After placing all our pieces, we have to do fillets in the perpendicular internal corners, this is with the pourpose of making an easier path for the machine and also will help to fit the pieces in each other.

7. Some pieces don't have all of its vectors together, for that we can use the Join vector tool that is located down the Fillet tool.

8. Once all the pieces are in place, the vectors are connected, and all the dog bones are done, the next step is make the external and internal cut. For that, we have to select Tool trayectory, which ist the first symbol in the right side menu.

Milling cutter. This Parameters are specifically for the tools we have in our Lab in Puebla.

External Cut.For the outer cut, the first parameter to set is the cutting depth. In my case, my material is 12 mm thick, so that is the depth I set, starting the cut at height 0. The next important parameter is where the cut will begin; Vcarve offers three options: outer, inner, or over. In this case, I will start from the outside in a counter-climb direction because it yields better results. Finally, it is necessary to add tiny bridges to prevent the part, when cut from the outside, from detaching from the material and being damaged by the passing milling tool.

Internal Cut.For the internal cut, the first parameter to set is the cutting depth. In my case, my material is 12 mm thick, so that is the depth I set, starting the cut at height 0. The next important parameter is where the cut will begin; Vcarve offers three options: outer, inner, or over. In this case, I will start from the inside in a counter-climb direction because it yields better results. Finally, it is necessary to add tiny bridges to prevent the part, when cut from the outside, from detaching from the material and being damaged by the passing milling tool.

Bridges.To add bridges, go to the “Tool Trajectory” section and select whether you want to add bridges. A small menu will then appear where you can choose how many to add; in the image, 8 are selected, but I used 4 in my parts. The bridges are placed automatically when you click “Add Tabs.”

Recomendation. The separation between two pieces must be more than 23 mm, in order to have more grip to the board.

9. The next step is export the toolpaths in the preview window. This feature allows the user to simulate the machining process and provides a 3D visualization of the material after the cutting operations.

If the project contains multiple toolpaths (as in this case), they can be reordered by dragging them within the toolpath list, allowing the user to prioritize the order in which the CNC machine will execute each operation. For save the G-code we need to:

Click on "Save Toolpath".

Format. Depending on the machine we will use, we can save it for the Mach 2/3 Arcs (mm) (*.txt) and for the Asia Robotics.

1. The machine I used was the Mach 2/3 Arcs router. The first step is to turn on the computer and place our file in it.

2. To turn on the router CNC we have to press the red button and make sure the variable frequency drive is on.

3. Then we have to place our board over the sacrifice bed (spoilboard). To prevent the material from moving during cutting and for safety reasons, the board is fixed to the base with nails. This ensures that the material remains completely immobile while the CNC tool is in operation, thereby preventing potential machining errors or accidents.

4. The program used to operate the CNC machine is AR2400. After opening the program, we have to open our file, make sure the parameters are correct and the run it. The CNC machine can also be controlled using the keyboard.

5.After the machine origin has been correctly set and the CNC program begins execution, the machining operation must be monitored at all times. As the cutting tool moves through the material, it produces large amounts of sawdust and wood debris. Allowing this material to build up near the cutting zone may create a fire hazard because of the heat and friction generated by the spinning tool. Therefore, the debris should be removed continuously, commonly with a vacuum or dust collection system, particularly around the areas where machining is taking place.

1. First we have to gather all of our pieces and sand the down.

2. Having sanded all our pieces we need to use some anti insects product. Which is a product specially formulated to protect wood from insect damage. To apply it we just have to use some cloth and wear gloves.

3. Then we need to gather all the paintings we need to get the right color. I also got some thiner to dilute the paint.

4. After that we need to mix the color to get the desired result and, once obtained the desired color, we need to give from 2 to 4 hands to our pieces to achieve a good result. The paint ratios depend on the desired result. In my case, I used approximately 40% American Oak, 30% cedar, 20% dark wood, and 10% thinner.

5. Finally, we have to apply the Nitrocellulose on our pieces. To use the Nitrocellulose we first have to delute it with thinner, approx. 10% thinner by volume. It is recommend to give 2 or 3 hand per piece, leaving a 60 minutes gap between each one.

1. Once all the parts have been painted the desired color, the inner walls and the top should be secured with M8 screws, for which space has already been provided in the design.

2. Because the parts are manufactured with very tight tolerances, some force is required during assembly to properly fit them together. To avoid damaging the pieces, a scrap piece of wood can be placed between the hammer and the part. This allows the wood to absorb the direct impact while still transmitting enough force to assemble the components correctly.

3. Finally, it is important to be carefull while placing the top part, because it has to fit in three different section. My recommendation is to fit each piece in gradually, working on them all at the same time until the wood is securely in place. The reason for this is to avoid damaging the pieces; when I was putting it together, I had to use a lot of force and almost damaged an interior wall.