Group assignment week 3 Andri and Hafey performed in Fab Lab Reykjavík. The lasers in the lab are Epiloge mini. We made a file with a grid to show rastering with different power and speed settings (see image) we used 600 dpi We did the same file as the raster, just took the fill out and put cutting lines (see image) but like you see it did not go through the wood so we did the same but with slower setting, there a lot of them cut through but as you can see on the image of the back some were too slow. These tests make since, since the settings we use for cutting wood in the laser cutter here in Fab Lab Reykjavík are Raster 60/100 and vector 11/100/500.

For the kerf test we cut out a 10mm x 10mm rectangle and measured how much material burned off. We also tried a different method where we cut a rectangle with cutting lines in it and seeing how much would burn off. I had already done some kerf test boxes and the 0.08 was the best and by the 10 x10mm test that seems to make sense. By the end we made a laser cutting template for wood just to have in the laser room.

He showed us what we would most likely use the most which was the Continuity beeper to se if there is a connection between spot A and B, Resistance to check how many ohm a resistor is, it is good to always check, they don’t always end up in the draw they are supposed to, it is also always good to know how to check the volts and frequency.

We also got our college Arnar to show us a little on the bit on the oscilloscope, where he connected it to a circuit board that was being used to control a maze game with a PlayStation controller. The signal that is displaying is when the motor is being moved.

To be able to use the shopbot at Fab Lab Reykjavik you need to take a safety course. The safety course addresses the dos and don’ts of using the shopbot. The safety course also goes over in which order the machine should be used, start the milling motor spin before turning on the vacuum. We do this so we hear the motor spinning. If the motor is not spinning when you turn on the project the shopbot would try to mill the project with no rotating milling bit resulting in breaking bits. After the vacuum is turned on and the shopbot starts the project it may be good to use ear protection but still make sure you hear if the shopbot makes weird noises. You also get training on how to change collets and bits.

Important takeaway from the safety course is protect you eyes, hair and clothing. Listen and look. And of course know where the emergency stop buttons are placed.

In VCarve I created a 100mm square with a 50mm circle in the middle. I made a pocket toolpath for the circle that went down 5mm. After milling the piece we measured each side to figure out if the Shopbot was accurate enough. The measurements showed the Shopbot was pretty accurate and within acceptable margins of error.

Andri created a comb test similar to the test made for the laser cutter. I created a comb test similar to the test we made for the laser cutter to check the kerf. The material I used was 14.5mm thick and I created three slots to see which slot size would make the best connection. One slot was 14mm, the next 14.5mm and the last 15mm. The 14mm slot was too tight and the 15mm slot was too loose. The 14.5mm slot was the perfect size. Hafey made a DúbbíDúb test to see which tab size and hole would make a good press fit. Using the same size for the tab and hole made a perfect fit.

To calculate the chip load I used the this function: feed rate (mm/min) / (RPM x number of flutes) Using a 6mm endmill with two flutes, 14000 RPM and feed rate at 5000 mm/min the chip load calculates to: 5000 / (2 x 14000) = 0.178

Andri was already familiar with an old version of Mods to mill pcb boards and went over the process with Hafey. Fab modules is run loacally on a raspberry Pi that is connected to the Roland Modela MDX-20. We access fab modules through the local network, in this case by going to a browser and visiting (ip address: port) 10.50.0.22:12345 In fab modules we start by selecting the input format, I always use the image(.png) option. Then you need to select the output format, in my case I select Roland mill (.rml). Finally we select the process, to mill the circuit we use PCB traces (1/64), to cut the outline of the board and through holes we select PCB outline (1/32). On the right hand side of the browser you can mess with the settings for the mill. Start by selecting the machine under output. In my case I select MDX-20. Under output you can see the speed mm/s and the xyz position of the machine. I have been using the default 4 mm/s for the speed. You can input new coordinates for the xyz position and hit the move to xyz0 button. But before hitting the move to xyz0 button you need to go under process and make sure the server field is correct, in my case it should read 10.50.0.22:12345.

Under process are more settings to consider. Cut depth (mm) is set to 0.1. If the the traces do not mill through the copper make sure that the z axis is properly set and that the board is properly fixed. Then try again with cut depth(mm) at 0.1. If the traces are still not going through the copper you can put the cut depth to 0.11 - 0.13 and you should definitely get through the copper. The next setting is tool diameter(mm). The 1/64 milling bit is about 0.4mm in diameter so I usually keep it at 0.4mm. However, if you have very tight traces, less than 0.4mm you can edit this field to "fool" the machine into milling tight traces. I´ve successfully milled traces that are 0.3mm wide using a 0.4mm milling bit by editing the tool diameter field to 0.3 and hit the calculate button to see if the trace visualization changes. The rest of the settings I usually just keep at default. When you are done with the settings you hit the calculate button to visualize the milling process and finally hitting the send button will start the milling.

To drill holes or cut through the board I open a new browser window and go to the ip address: port, 10.50.0.22:12345. I select the same input format and output format as before but under process I select PCB outline (1/32). The settings for the outline process are very similar to the settings for the traces process. The main difference is that the cut depth is set to 0.6mm per pass, and you can input the material thickness. When you are done with the settings you hit the calculate button to visualize the milling process and finally hitting the send button will start the milling

For our group project we measured the power consumption of a SSD1306 OLED display. We used a multimeter and started by measuring the volts. We put the probes from the multimeter on VCC and GND on the SSD1306 OLED display. We got a reading of 3.3 volts which makes perfect sense as the OLED is connected to the 3.3v output from the XIAO.

Next we measured the amps. We wired the display to the GND, SDA and SCL but interrupted the wiring from VCC with the multimeter in between. We got a reading of 0.006 Amps or 6mA.

Group assignment for machine week on group site

For our group project we probed the input signals of a PlayStation remote, controlling stepper motors. The PlayStation remote is connected to a Stepper Motor Control Board controlling two stepper motors controlling a maze game. The PlayStation remote is hardwired and the probes are connected to the Stepper Motor Control Board. Using an oscilloscope we probed and measured the signals from the PlayStation remote controlling the stepper motors.

The oscilloscope shows how electrical signals change over time by graphing them as waves on a screen. It displays these signals as waveforms on a screen, allowing you to visualize the amplitude (strength) and the frequency (rate of change) of the signal over time. This helps in analyzing and troubleshooting electronic circuits and systems.

We started by going over our inventory. We had some epoxy but that was pretty old so we weren´t sure if we should use it. So the only materials we had were Dry-Stone Casting Media and construction cement, besides the soap and chocolate we used in our individual projects. We did however go over the safety warnings for using epoxy. The chemicals in epoxy resin systems can affect your health when they come in contact with your skin, or if they evaporate or form a mist or dust in the air you breathe. The main effects of overexposure are irritation of the eyes, nose, throat, and skin, skin allergies, and asthma, so using personal protective equipment is a must.

Make and compare test casts with each of them Following the instructions for the Dry-stone we mixed 50 grams of the Dry-Stone powder with 10 grams of water. Always mix the powder into the water, not the other way around. The two were mixed together for a minute before being poured into a container. The Dry-Stone was hard within an hour and was smooth to the touch but still had some water that hadn´t evaporated. Following the instructions for the construction cement we mixed 15 ml of water with 25 grams of powder. Always mix the powder into the water, not the other way around. The mixture was then poured into a container.

We took Hafey’s master and nodes and added a node from Andri and changed the code accordingly, it went very well. Links are below the video.

Links

Download Master group

There are many tools to make a GUI to display and interact with data.

Blynk

ThingSpeak

Firebase