projects

Twitter tee-bot

The goal is to create a twitter bot which, when tagged on a tweet, generates a checkout page for a t-shirt with the screenshot of that tweet on it. To support crypto payments since twitter gives an option to add crypto wallet address.

OTA UPDATE WITH ESP8266/ESP32

Fed up with the tangled cables, I decided to try out OTA update on NodeMCU. Things could have been easier if I could just compile my code on laptop and login to a server hosted by the NodeMCU and upload my code. Luckily someone already did all of that already in the exact same way and made a tutorial, check it out. It hosts an http server where yu can upload the binary, once it is uploaded, it copied it to EEPROM and boots the binary. Remember, you need to include this piece of code in every binary for it to work as it contains the part that hosts and updates the code if a new binary is given.

Laser Engraver Mod for any 3D Printer

Typically a 3D printer to laser engraver conversion requires few additional components and even replacing the micro-controller and/or firmware sometimes. I wanted to eliminate that additional efforts and expenses. A 1 Watt laser(I bought last year from Aliexpress for $17) and a typical 5V phone charger to power up the laser is all that you will need for this mod.

Disconnect(or even remove) the extruder from the printer Clamp the Laser on the extruder mount and you are done with the hardware side changes.

How to Engrave?

• You will need the vector path(svg, dxf, etc.) of the image that you want to engrave. For that, use any photo editing tool to convert your image into vector. I prefer inkscape because I can export it into a dxf file using an extension and then use that dxf in OpenSCAD directly.

• Now import that vector into any CAD software and extrude it to height = 0.1mm (1 layer) and save the 3D model.

• Now open the model in your slicer, translate the model in Z axis by 3-4 cm and use the following settings:

  • layer height = 0.1 mm; extrusion width = 0.1 mm

  • Filament temperature = 0; bed temperature = 0

  • Print speed = 200 mm/min

  • No Supports

• Just when you start the engraving, the laser will lift up to that 3-4 cm height that you translated you model. Make sure you adjust the focus after that z axis translation such that the focus of laser lies on object you want to laser cut.

How it works?

The laser is switched on when the printing starts and it is kept on at full power till the engraving is done. By adjusting the print speed, we ensure that the laser engrave/cut the paper only when we want it to cut. We want the laser to cut only at the time when we should have printed, if we were printing the same model. So, It reduces the speed(thus, start cutting) when it thinks that it is printing, and when it is moving from one position to another, it moves at a ~25x faster speed(thus unable to cut through the paper)

We want to control the energy bombarded on different points, but we cant control the power of laser, so we are controlling the time a laser spends at each point(by controlling speed of x-y motion)

What next?

I am gonna try to do laser engraving on a curved surface by making a curved single layer model of the object I want to engrave upon(preferably a cup).

3D Modeling with OpenScad

For someone with basic programming skills, OpenSCAD makes things really easy when it comes to 3D modeling. There are a few basic shapes like cylinder, cube and sphere on which you can apply geometric transformation like translate, rotate, scale, mirror etc. to make different objects and even combine multiple objects with the help of union and difference function to make more complicated objects. Moreover you can even make objects from 2D sketches(which by the way can also be imported in form of dxf/svg/etc.) by using linear/rotate extrude functions. The syntax is quite similar to C and you can even define modules for sub-models just like functions in C so you don't have to repeat the same code again and again at multiple places. I made the model of a parametric BITSian ring(Thingiverse) with ID number and ring size as input. The code will generate a model based on input parameters and generate a customized model for the user which they can 3D print. However due to the details in logo, I can't 3D print it on my FDM printer. Searching for a DLP printer now to get the ring 3D printed.

Update: importing a file does not work with Thingiverse, though there's a hack available. You can convert svg into OpenSCAD directly using an inkscape extension and then copy paste that code into your original OpenSCAD file and use it.

Makers Community

I have been trying to find a community of makers in India. Witnessing the "Jugaad" everywhere around us, I believe India has a great potential to innovate. We even have resources upto an extent to begin with, the only thing lacking is a forum for people to discuss.

Me and Ajinkya started reading about 3D printing from some Facebook groups. Those groups were quite active and informative. From researching about which 3D printer to buy, to asking all the troubleshooting doubts - people in those groups helped us with everything. Inspired from that, I am planning to build a forum(maybe just an FB group for now) where people can post about their projects, seek advice/advise, post events/ workshops/ meetups and find people to work with on projects. I don't want it to be limited to just India, it is open for anyone from anywhere. It is just the geographical constraints that made me feel like this group will be more relevant if its limited to India.

UPDATE: I think reddit can serve the purpose better since facebook is kind of dead now

Maker Faire 2018 (Hyderabad)

The first Maker Faire in India! Couldn't miss it. I think they did a pretty good job considering its their first time. To be honest, I had not expected that I will be witnessing so many makers and maker culture in Hyderabad. The whole makerfaire was divided into 3 major parts analogous to the 3 major sponsors -

• • Startups (FirstBuild, Swissnex)

  • Students' projects (NITI Aayog - Atal Tinkering labs)

  • Makers/Artists/Maker spaces (T-works)

A few glimpse from the MakerFaire:

Beginners guide to FDM 3D Printing

• 3D printing community - You'll find all the FAQs just by reading the posts of a few FB groups. Took us less than a day to finalize which printer to buy and all other newbie doubts. You will also need this while calibrating your printer for the first time.

• Aliexpress/GearBest/Wish/Banggood etc. for ordering. I ordered mine from Aliexpress.

• Order kit and assemble as instructed in YouTube guide, buy RepRap based machine. RepRap has a huge community, so any problem resolves fast. Parts are easily available everywhere, many mods and upgrades available.

• Slicers - Simplify3D is the best I've used. CURA is best among the free ones.

• Try out new Filaments - PLA, ABS, PETG, Nylon, Wood, Copper, CF based filaments.

• Make your own Filament - Another cool thing to try once you are into 3D printing.

• Mods - Laser cutter, CNC, extruder, bowden extruders

• DLP/SLA printers - Mostly needed for high precision(~50 micron) parts. Personally I've only seen these commercially used for printing dyes/models of jewellery and dentist applications

• 3D scanners - Although there are many plug and play options available like the Occipital structure sensor and even kinnect, I've seen mostly people use rotating platform based setup and Intel RealSense sensor.

Laser Cutter mod for 3D printer [Part 1:The Idea]

Ordered a 1 Watt Laser, arrived a week ago. Have been playing with it since then like lighting up matchsticks, cutting paper etc. It can be used to engrave on wood, but I think 1 Watt won't be enough to cut wood or acrylic.

Also, this laser emits 405nm light. This means it can also be used for SLA printers, since this is the ideal wavelength for curing most of the resins.