Electronics Production¶

I. Understanding the Machine¶

Machine Name: Roland monoFAB SRM-20 This machine is used for subtractive milling

Parts¶

1 - An arm that moves in X,Y, and Z axis 2- An Endmill which comes in 3 sizes 0.010 - 1/64 - 1/32 3- Material: In this case we used copper. However, this machine is capable of cutting other materials such as: Chemical Wood, Acrylics, Poly Acetate, ABS, Modeling Wax, Styrofoam, and PCB Board 4- An underlay: This part is an additional part that was made in the lab by using two pieces of 19 ml mdf glued together with a thin layer of super glue. ( we needed to cnc that and use it because the endmill doesn’t go all the way down so we needed to raise the cutting bed. 5- A cutting bed that allows for materials up to 8” L 6”W 2 3/8” H

II. Using the Machine¶

Step 1: Material Fixturing¶

Fixing the material using double sided tape

Step 2: Leveling¶

Using the leveling tool, we ensured that the material is straight on the machine bed

Step 3: Installing the Endmill¶

This process needs to be done very carefully as the endmill is very delicate and might break. see video below to know how you should do that.

III. Preparing the File¶

This machine will recognize files in .rml format. Thus, we need first to convert our png file to .rml through Mods

Mods¶

What is Mods?¶

“Mods is a project lead by Prof. Neil Gershenfeld in the CBA that allows one connect modules, i.e. devices that do very specific tasks, using a friendly web interface. It allows people to use a web-browser to connect devices and do computation.” T.Evan

How to access it and use it ?¶

Step 1¶

Go to http://mods.cba.mit.edu/ . Alternatively, you can google Mods MIT and press on the first link.

Step 2¶

When we first open mods, a blank page will show. Follow the next steps illustrated in the image below to see how we specifically opened our machine settings page

Below is a close-up of the components that we used

An extra step we made was to add a component so we can save a file on the computer instead of letting Mods to send it to the machine immediately. See images for the steps

The changes we made on each component were as follow:

1- Select png File >>linetest>>traces 2- Set to mill traces (1/64) 3- Change speed to 1.5 4- Click on calculate. View will show you an image with arrows (black lines indicate milling layers-red lines show direction of milling arm) 5- File will be downloaded

IV. Software : V Panel for SRM-20¶

1- we control the movement of machine axes from this software using the arrows 2- We can control the cursor step by choosing one of the following values - x 100 = 1mm - x10 = 0.1mm - x1= 0.01mm

We followed the following steps in order to start the milling process:

Step 1: Set the x and y by moving the arrows manually in the software to the desired location Step 2: Move the z axis slowly and carefully until it is very close to the material. here you need to slowly loosen the endmill and make it touch the material and then tighten it again. ( This step is to ensure that you will not break the endmill as it is very delicate and can easily break) Step 3: Go to “set origin points” and press on x/y and z >> this is what is called zeroing

Step 4: Press on cut

Step 5: Adding the File and Sending it to the Machine - A window will pop where you need to delete older files and add your .rml file from the location you saved it in from mods - Press on output then the machine will start the job

For cutting the Interior of the board (the outline of the ship so we can take it out) we follow the same steps as before however we need to make some changes to the machine, mods and the software:

The Machine:¶

We need to change the endmill from the one we used 1/64 to 1/32 . This must be done gently

Mods:¶

file : linetest interior set 1/32 speed 3

Software:¶

The x/y axis this time we do not move it manually as it needs to start exactly where the previous job started so we move it “to origin”> x/y
Then we move manually the z axis until it reaches the material and then set origin on the z axis

Then cut and we delete the previous file> add the new file > output (as illustrated above)

LineTest Results¶

This indicates that whichever distance that is less than 1/64 will not be visible and lines will connect. This is determined by the radius of the endmill.

References: - Ivan Tadeu Ferreira Antunes Filho http://fab.cba.mit.edu/classes/865.18/people/ivanaf/armod.html