Moving home [x0,y0,z0]to "Detonador Space"

For this assingment, we have moved to a space located in the district of Barranco, Lima-Peru. It's called Detonador Workshop, and it's Jose Luis's space , my older brother. Several activities related to art and architecture operate here. Barranco district is located on the coast of Lima, next to the sea, a place full of cultural, artistic life and tourist activities. In our usual laboratory Fab Lab Lima, we don´t have a CNC Router to cut wood and we don´t have enough space to carry out this type of task. Here, we have many tools for wood and metal work, plenty of space and we are outdoors for better sanitary conditions.

I had a half-assembled CNC Router at home, I mounted it in the car and took it to Detonator. Now we have a medium CNC that we are going to implement to take on this challenge. So together, with Mayra Ascencio, and the Fab Lab Lima Team we got down to work!
First, I designed the table on which we were going to put the CNC Machine. I designed it in the class of week 2: Computer-Aided Designed, (👉here you can see its development). I used Rhinoceros and then cut the pieces in 18mm Plywood. Already in the workshop, we assembled it and installed a slaughter table, for this I bought a MDF-grooved board and sectioned it into several parts. So we have 4 pieces to sacrifice!🤩

Homogeneos Residence Lab is a project under construction housed inside the Detonator workshop. It is a digital manufacturing laboratory as well as a traditional one. This space allows the artist, scientist or creator, national or international, to carry out a residency to experiment on the subject they want. At this residency, the emphasis is on providing follow-up and support during the resident's creative process. The resident will finally decide whether or not to expose their research. This space aims to provide the community with a valuable exchange of knowledge between cultures. We are carrying out the implementation of this laboratory right now, which will have CNC cutters, 3D printers, laser cutters, tools to make sculptures, electronic components and even audiovisual equipment.

The CNC Router Hybrid 000-490

Two years ago, we acquired this CNC machine, it is approximately 20 years old and it was built as part of the thesis of the electronic engineer Jorge López, we thank him very much for his contribution. It is based on a manual router, motors and belts. The entire electronic system is very old and some parts have been replaced by modern parts, such as the motherboard. Now it works based on Arduino, but the drivers are the original ones, huge! So we have a great hybrid going.

GroupTask

The group assignment this week is about testing our machine, test runout, alignment, speeds, feeds and tool paths and we have to document this entire process. Next we will see the arduous process that we take to start the CNC and have our first test. For this we needed to get many things, for example, the cutters for cutting, the programs to manipulate the machine, the material that we would cut (wood), a vacuum cleaner, screws, screwdrivers and many more tools that we would probably find in the workshop Detonador.

Recognizingthe GRBL

We'll start with the perse machine. A year ago I had installed an Arduino UNO alongside a CNC Shield Board, which already had the GRBL loaded on the board. The GRBL is open source firmware that runs on an Arduino UNO that converts G-code commands into step-by-step signals. Our machine works based on 4 stepper motors, in the three axes X, Y, Z and has an extra motor in the X axis. Unfortunately none of our laptops recognized the Arduino and we could not control any axis, 0 movement. To solve this, we had to update the USB port driver on all of our computers and we were able to recognize the machine.

Components of our CNC:

• 12v and 15A power source
• 1 x CNC shield
• 1 x Arduino UNOR3 board
• 4 x original drivers.
• 4 x stepper motor
• 1 x USB cable

We tested with the CNCjs program and with the GRBL Controller program. Finally, after updating the USB port driver, the two programs were able to recognize the machine. It is very important to select the value of 116500 in the Baud Rate Parameter (this is the appropriate value for our machine) so that the CNC can be recognized correctly. To update the COM port driver, we use an Offline method. Download the driver PL2303_Prolific_DriverInstaller_v1210, install it on the laptops, and then you must go to Device Manager >> COM Ports >> Select the corresponding port (COM3 or COM1), right click >> Update Driver, manually choose Update the Version 3.3.11. This will update the COM port and when opening the GRBL Controller if it will recognize the machine.

Testing& Drills

When the driver is already installed. We went on to test the different softwares that we can use to control the axes of the CNC machine. Here at Homogeneos Lab we work with a built-in, high-performance open source CNC milling controller and g-code analyzer written in optimized C that will run on a direct Arduino called GRBL Controller and we had previously used the CNCjs, other software from open source that serves the same functions. So we decided to try both.

Drills

When the driver is already installed. We went on to test the different softwares that we can use to control the axes of the CNC machine. Here at Homogeneos Lab we work with a built-in, high-performance open source CNC milling controller and g-code analyzer written in optimized C that will run on a direct Arduino called GRBL Controller and we had previously used the CNCjs, other software from open source that serves the same functions. So we decided to try both.

Testing the machine

The first thing we did was to generate two small rectangles of 40x40mm. to see the accuracy of our milling machine in terms of straight cutting and to see the precision. The final pieces were 40.03 mm on each side, which is the right size for an accurate assembly.

Joint test

We designed a first joint exercise, it is a simple fitting where we wanted to test how we would fit our 15 mm. wood, for this exercise we used recycled wood and we designed the first test objects in Rhinoceros, this object measured 50 x 10 mm. and it was a 15 mm. thick wood, we used the dog bone technique with a diameter of 7 mm. because our milling cutter was 6.3 mm. and we rounded all the corners to ease the milling cutter path. In addition, we left a tolerance of 0.5 mm. in the total width of the socket to check the kerft what was the final measurement of the cutter and if the socket was going to be efficient.

First cuts

Before developing the design further, we create the first cuts. For these first cuts, thanks to iFurniture we were able to have a lot of material to make the pieces, this material was recycled. In this case, as our CNC is small, it was convenient to have the scraps to be able to use them with the dimensions we could work with. We use Artcam to generate the G-code and GRLB controller to manipulate the CNC machine.

Improving design

After the first tests we could see some flaws in the design such as the angles of the roofs, the joints, the union between the pieces and the sequence of assembly. For this we proposed improvements in the design such as the angles in the roofs, the improved assembly sequence, the different heights, the angles of inclination in case it rains, although in Lima it rains little, the overlapping of the pieces, the rotation of the window and all the considerations to take into account so that our design works well.

Cutting the skylight

To start cutting our skylight design we had to follow a process in different software, first the design was made in Rhinoceros, since our machine has a cutting area of 66 x 46.5 cm. the pieces were arranged each one in a piece of wood and then exported in DXF, because our CNC is small we could not cut more than one piece at a time. The next software we used was Artcam to generate the G code, at the end we used the GRLB Controller software to cut the parts. Due to the size of our CNC it generated an endless list of cutting files, however the task was accomplished successfully.

Roof cutting

To cut the roof was divided in two by the size of our CNC, for this we designed a piece with a rebate at the end so that it can be joined to its pair, in this way we obtained the piece 1a and 2a, this piece needed to be cut and rebate at one of its ends to half its thickness. To start the cutting we need to convert the .DXF file to G code using Artcam software, for this process the following steps were followed:

Window cut

In order to cut the window, we first created a test file that allowed us to see which dimension had the best rotation and at the same time a smooth rotation at the window hinge and at the window axis.

The best option for the window hinge was size 5, where the circle had a diameter of 25.00mm and in addition we added a tolerance of 0.5mm. We used this circle size in all the pieces that received the windows. In the window frame we chose to use the 20.00 mm measurement that corresponds to the 1A-2A test. With these two sizes the window glass was smooth.

The window frames were custom-designed with recesses so as not to clash with other parts.

Assembling skylight

After finishing the design we cut the model of the skylight in acrylic to scale to validate the sequence of the assembly. How is it done? you reduce the file so that all the sockets are of 3 mm. which is the thickness of the acrylic and then cut it in a laser cutter. In addition, all the pieces are labeled to identify them and make the assembly easier.

We put all the cut pieces of wood where they were to be assembled, joined the pieces that were cut separately and once everything was ready we proceeded with the final assembly in the correct sequential order without the need for bolts or screws.

Final

Finally, together with Mayra Ascencio, we were able to assemble the skylight, which is a really big element of 2.0x1.0 m. approx. where the windows work perfectly.