Build your own Risha

Documentation > Build your own Risha

Risha is an ongoing and open project, meanwhile we develop our next prototype, we are happy to invite you to replicate our latest iteration, which is fully functional stable and cute.  The machine is designed in order to be fully fabbed in a hackerspae, or fablab, or at home.   No complex machinery is required. Just a 3D printer and some standard hardware parts. Same for the board, you can cnc it in a lab, or you can replicate it using the DIP components and old 60s method. It will still work :).

Below are sample quick steps, until we release a full detailed Risha manifesto.

So first things first:

1.  Check the BOM

Please feel free to use recycled components from old devices.  Old printers are a great resource for 8mm steel rods (each printer has at least two).  Bipolar steppers are also possible to find, in newer printers, or in large photocopying machines.  Nothing is wrong with unipolar motors, however microstepping those is a hassle that we have been through (documentation archive is coming soon!) and which we want to save you time going through as well.

The BOM includes parts to replicating Risha shield, which contains motor drivers, laser drivers, and is designed to work on arduino mega.   If you have another cnc control board that you would like to use (RAMPS, Smoothieboard, Rasbperry pi, etc..) that is possible of course, however, you will still have to replicate the laser driver part and connect it via PWM to your board (will publish a detailed tutorial).   Talking about laser diodes, we added some references in the BOM, however, if those are still difficult to order in your country, let the hacker inside you shine, and feel free to hack a blu-ray DVD and use the diode inside, like this instructable.  It will still be powerful enough for fabric and paper, just might be a bit slow.  As you know, any laser above 5mW is dangerous for your eyes.  PLEASE WHILE TESTING USE GLASSES THAT CORRESPOND TO THE DIODE WAVE LENGTH.    Risha encloses the laser diode in a heatsink and a cap making the beam totally invisible while in operation. While you are building the machine, and if you are using different specs from ours, you will go through testing, focus adjustment, etc. DO NOT START THESE PROCESSES WITHOUT GLASSES.  It is tricky, of course, because you won’t go blind once you look at it, but you will be affected after hours of testing, so please keep your eyes safe. Please.

 

2. Print your parts while you wait for your hardware to arrive

Please download STLs from github, they would take around 6 hours to print ..or 6 days. Depending on your printer.

 

3. Build your mechanics

Following the sample guide below, you can simple put your parts together.  Kindly note that we milled our own heatsink.  If you don’t have access to a cnc, or to the raw material, please use our alternative laser bracket with a fan for your laser mount and Z axis..

ManualNEWFORWEB

 

Adjust your alignment, otherwise the machine will not move.  Make sure all is nice and easy. Use common sense, and some lubricant spray if needed and all shall be fine.   Now what?  Electronics..right.

 

4. Build your electronics

Well, below is a super sample illustration that tells you what happens in the board. If you are an advanced user, please feel free to hack the machine and share your hack. Hacking can range from re-routing the current schematic, to changing the board entirely. All is great contribution, as long as they are tested trials that actually work :).

So, lets assume that you will etch this board manually.  You can either do it with the help of the lab next to you, or you can talk to your electronics guru neighbour or friend, or ..you can Do It Yourself.  Learning while making is a fun process, a tutorial like the one on hackday or wikihow can be of help, just make sure you find your localized components.  The current tracks are made big and super legible and easy, so that it is easy in both fabrication and understanding.

If you don’t have eagle, please download it, they offer free versions. You will need something above v6 to open the .brd file on gitgub.

Click print and adjust your file to be saved as pdf.  This shall be your board file.   (Hint: Make a test print first, before you print on glossy, scale can go wrong, based on your pdf reader/printer).  In the manifesto we will publish a step by step guide to how this shield was made.  You need to drill and solder and test, and makes sure all works well before moving to the next step.

5. Code your electronics

Now bring your arduino.  If you are an absolute newbie to arduino, take a little time make yourself familiar with this thing. Getting started guide is a great place to start.   Assuming that all goes well, then go to github and downlaod the library here, unzip the folder, put it in your arduino library folder (make sure arduino is closed while doing so, or else just restart arduino before you open the example). Open arduino, open the sketch found in the folder you just download from Examples, then upload. (There are some complaints from sketch upload errors on Mac, however all goes well on Linux, we are still tacking the problem).  Once uploaded then your sketch is ready on arduino.

Now lets get your AVR ready, if you have an arduino uno, all you have to do, is to copy and paste the code on github, then upload to your arduino, remove the AVR and it is ready to go.  For standalone programming, you can use arduino as ISP

6. Initial testing

If you have reached that far without trouble then you are good to go.  So now, lets test the mechanics and initially test the laser.  Connect your board to your arduino.  Power it (12V-5Amp). Connect arduino to your lap top. Open arduino IDE or any other serial terminal. Make sure baud is 9600. Type vector (just the word vector, all is small letters), and click send or Enter. You should get a GRBL message.  Then type x10  and see if your machines moves in this direction. Type y10. All is good..then you are great.  Now to test the laser.  Type P100 (to set the power to 100).  Then type m3 to power your laser on.  You should have laser turned on at max.  Type m5 to turn it off.  If all is well. Then you are really very happy go test with your app.

7. Testing Risha app

You will find the exe to your app on github.  Extract it. Now after powering the machine, connect usb to your computer, and open the app. Select your serial port and click connect.  P stands for laser power.  Vector and Raster stand for cutting and engraving.  This app still needs lots of development, but it works perfect for sketching and cutting or engraving B&W bmp or png.

 
 

 Want to get involved?   Please …

1. We need a donated 3D printer so that we continue developing our prototype

2. We need a mobile app developer who can work for free

3. We need to re-route the board for easier cnc machining. Slimmer tracks, smaller size, etc.

4. We need a new board logic that gets rid of AVR and linear modulation.

5. If you are a friend of C#. Visit the code on github. DXF needs to treated as vector not as raster. Debug/fix..have fun!

Non of the above? Why not. Just write to give us a high five..

Now what?  Give it a try and build one.  Hack it.  Share your build. Drop us a line :)

 

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