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Prusa SL1 SLA 3D printer build and first impressions

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I ordered this printer almost a year ago, but then the MINI appeared and I decided to get a MINI too, so my new order was delayed due to the MINI massive backlog. It was delivered last March, just at the beginning of the pandemic, so I thought I would have plenty of time to devote to it. But I was wrong and it has been sitting inside the box in our home's hall for several months.  To be honest, I knew the resin will be smelly so I was not eager to build this printer unless I had a use for it. That and the almost unavailable Isopropilic Alcohol (IPA) that was needed kept the project on hold. But given I finally got a good deal for IPA on Amazon something needed to be done.So last Saturday morning I started unpacking the several layers of foam with parts and went ahead building the Prusa SL1 printer. I would say it was simpler than the MK3, with lots of folded metal and machined aluminum parts and just a few 3D printed parts. Lots of screws and a good number of active parts and elec…

Road-trip time-lapse

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A while ago I bought my second action camera, this time I made sure it could do a time-lapse video (something the first one I bought was not capable of). Anyway, the camera sat on a shelf for more than a year. But during the summer holidays, I was doing a trip and I thought it would be cool to create a hyper-lapse of my drive.As usual, things went wrong when I was about to fix the camera to my car's windshield: it was not possible to fix it properly oriented, so the camera did the recording upside-down. I was not sure I could easily rotate the recording but I was positive I could rotate images so I decided to record the time-lapse as a sequence of JPG pictures. I checked there was enough memory available on the SD card and I connected the USB cable from the camera to one of the car's USB power sockets. I stated the recoding and drove away. I could see the camera was doing its job and then I entirely forgot about it until we arrived at our destination four hours later.Once I r…

Fan blades replacement

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I have two fans at home, one of them is quieter than the other. I assumed the reason was the shape and number of the blades, as the noisier one features a 3-blade rotor while the quieter one is a 5-blade one. 
A good design exercise that might bring some real-life benefit if proved successful. So I went on and created a model using Onshape, that had to be able to be printed in the Prusa MINI. I designed two parts, the hub, and the blade, that will join with a dovetail. 
While I did not do an exact copy of the quieter fan blades, I tried to stay as similar as possible. Which may not be good enough for the best results.
It was also a project to explore the viability of the 3D printed approach. So this is what I designed: 
To my amazement, 3D printing the blades really favored printing them all together, as the print time of each layer was so small if printing just one that the print needed to be slowed down. So printing five blades did only required around 3 times the print time of printing…

First steps with a Duet 2 Wifi

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I have been testing a Duet 2 Wifi board lately. It is the first 3D printer / CNC controller board that I use that has a decent wireless upload speed. It is a well-thought-out board designed by David Crocker and Tony Lock, that features both an ARM ATSAM4E8E and ESP8266 module. The former handles the RepRapFirmware and the latter provides wireless connectivity to the mix. 
The board features five silent stepper motor drivers and heaters and fan controllers to be used on 3D printers or CNC machines. The built-in socket for an SD card allows its usage not only to hold the firmware and website files but also user folders containing g-code files that can be uploaded and managed remotely through the built-in web server. 
The only main problem for the newbie is SD card and board initialization, which should have been taken care of by the seller unless they are lousy. But the board I got did have an empty SD and no manual so I had to go Duet3.com site to get some answers in their Documentation …

Remote shutdown your Python program

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One piece of code for a project is written in Python and it does what it was intended to do but, out of the blue, I am asked about the possibility of shutting it down remotely from another computer (code is running on a server where I do not want other users to be messing around).

It was a perfect opportunity for using the threading library. So I went ahead and I wrote a small piece of code, encapsulated in a function, that will be run on a different thread. The main program is still doing its thing, but the new thread now creates a network socket and binds it to the proper IP address and port so it can accept connections from other computers over the network. When a new connection is made, the code will check if a special token is received, and if that is confirmed, it will shut down the whole program. Otherwise, the thread will loop forever in case new connections are made in the future.

So the question is how to shut down the program. Usually, I use exit(0) to make my program to fi…

Uploading code wirelessly to Arduino Mega

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Given the same thing worked ok using an Arduino UNO form-factor board with both an AVR 328p and an ESP8266, I was expecting not much trouble getting the same thing to work for a similar board in the Arduino Mega format.

Oh boy, I was wrong!

The hardware modification part was easy: Find the diode whose cathode is connected to the RESET pin and remove it from the board. (Board schematic)


I used GPIO12 as the ESP8266 pin to be used to reset the AVR processor (key for a remote upload).

But once the hardware was working, it became obvious the software side of things was just not working. I could see no communication was ever successful between the ATMega2560 and avrdude program.

Reset generation was not a problem as it was clear remote reset was working ok. Perhaps timing? Let us read about possible issues on github. It turns out this is old news, as ESP-Link is playing a trick to detect the attempt of a firmware upload so it can reset the AVR chip then. That detection was limited to the m…

Uploading code to your Arduino board remotely

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A while ago I bought some Arduino UNO and Mega cards that featured, besides the usual processor, an on-board ESP8266 processor to bring Wi-Fi connectivity to them. Theseboards, have DIP switches to be able to program either the AVR (Arduino) processor or the ESP8266 using the USB port (think of them as a sort of serial port multiplexer).

The main use for me was to be able to use them for different applications without using a USB cable. A [Wi-Fi]  TCP connection to port 23 would be used instead. As I am using ESP-Link firmware for the ESP8266.

Do you want to print wirelessly on your 3D printer? You can do that with one of these Arduino Mega boards that can use Marlin. Using Pronterface software you can print to a TCP socket the same as if you print to a serial port.

However, what intrigued me is that no mention was made in the boards I use about using the ESP8266 to upload new programs to the Arduino processor. And that was odd as ESP-Link software allows you to do that. However, in o…