Electronic production 2.0

For this tutorial i've made the brian's version of Fabtinny45 ISP and used a raspberryPI to programm the MCU using an Atmel-ICE and following brian's tutorial

you can see directly the tutorial on that respective part.

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Bill of materials

Brian Does a better job explaining the details on his board i'll only repeat what he has done.

1x ATtiny45 or ATtiny85
2x 1kΩ resistors
2x 499Ω resistors
2x 49Ω resistors
2x 3.3v zener diodes
1x red LED
1x green LED
1x 100nF capacitor
1x 2x3 pin header

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First Method: ModsCE

modsCE has a browser based toolpathgenerator (that's really handy 'cause you dont have to install another software)

i use firefox

first you enter this text on the browser

or click in HERE

and you'll see a white canvas and an icon that will tell you how to navigate

right click on the canvas will open the window on the image above. you'll have to select "program"

here you have to select "open program"

Here you'll have to select "PCB" under SRM-20 mill

this is the whole program on the roland machine don't worry you dont have to understand all of the blocks.

the first thing you'll need to do is to insert brian's traces png into mods.

you do this by clicking on the "select png file" on the read png block

HERE You can download brian's traces file

once loaded it should look like this.

Now, let's take a look on the Roland SRM-Relative block.

By default it comes conected with blue "wires" to the WebSocket device and WebSocket print like in the picture above.

you need to "unplug those wires by clicking in the "file" tag on the OUTPUT from Roland SRM-Relative block.

and then click on "file" tag on the input of the WebSocket device block.

Then to conect the output from the SRM-20 block to the save file block.

first you need to make click on the "file" output tag on the roland srm-20 block.

and then other click on the "file" input tag from the save file block.

when it done it should look like this.

this are the settings i used for the endmill we have in our lab.

this is the settings i used for the speeds and feeds

Now click the "calculate" button on mill raster 2D block.

you will be prompted with this window asking to save the file on your hard disk.

HERE You can download the outlines file from mods

then you can check the preview for this operation.

this is the overall vew of all the blocks conected.

now let's repeat the steps for the outline file

HEREyou can download my outline roland file.

You can download brian's outline file/a>

This is the preview you'll spect to see.

it's jus one line with diferent thicknes steps

this is the overall view of all the blocks conected

the parameters i used on the 1mm diameter endmill we have in our lab

the feed rate on the 1mm endmill

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Second method: VcarvePro

This second method i'll describe here is for the same piece and at the end i will show diferences between the 2 postprocesors.

Of course this setting will depend on the machine, the material and the endmill used.

For this tutorial i'll use the same 0.2mm endmill for the traces and 1 mm endmill for the outline cutting and holes if necesary

This are the two endmills used for both modsCE and VcarvePRO.

HERE is the link to buy the 0.2mm endmill

HERE is the link to buy the 1mm endmill

SO....

In my windows PC i just press the "windows" key on the keyboard and type "vcarve" it should appear to launch the software once the installation process completed

HERE If you wish to install the vcarvepro software for yourself.

it has a really usefull fretrial which leaves you use all of the tools all the time you need. and the only limitations it's that you can not save the G-code file without a license.

Vcarve enviroment

Like any other software you can create a new file or open an old one. Let's open a new file click on "create new file" or "crear archivo" (sorry for the "spanglish" but that's the way the software deals with spanish.)

the STOCK material dimension and caracteristics tab.

for this example i'll simulate this stock dimensions but i'll depend on my real material. the thickness of my pcb stock ussually is between 1.5-1.7mm.

Once you click accept "aceptar" button.

It will change into the drawing tools tab "dibujo" at the bottom of the tab.

in the left side of the screen you can choose between all of the drawing tools like any other CAD software. (drawing tools,import 2D-3D files,transformation,Orientation and such).

the first thing we need to do is to import our images and convert the "PNG's" into curves.

we import images from our HDD from the button called "importa el mapa de bit para el trazado"

i uploaded both of brian's files.

automatically sends them to the center of the stock.

We need to move them to a position we want to carve (this way we can process more than one pcb at the time)

using the button to move objects "mover los objetos seleccionados " under the transformation category.

This is how i move the objects, First select the bottom left corner on the icon of the move tab on the upper left corner of the image above.

then type a 1mm in x and y direction under absolute coordinates.

as i'm going to use 1 mm of diameter on the cuttin endmill that's the minimum i need to set to not waset any of the stock (if i had more than 1 pcb i had to leave at leas twice the diameter of the cutting tool between boards to cut them).

the "adapta los vectores al mapa de bits" button will create the curves from the bit map image.

once you hit click it will open the vectorization tool on the lef side of the screen.

vectorization tool window.

this are the usual parameters i use when i'm converting curves from images. (the more resolution "DPI" you give for a png the more accurate the curve generation will be).

once you got that settings right click on the "previsualizacion" (1)button this will preview the curves and then hit "aplicar" (2)button to appliy the changes.

Once that's done do a right click on one of the curves (they're group together so this will ungroup them) and select "desagrupar vectores/desagrupar en la capa original del objeto"

Then eliminate the outer contour that you won't need

click on the line you want to delete once selected i'll change color you can right click and hit "eliminar" button to delete.

or simply click on the line and hit the delete key on the keyboard.

eliminate the bit map from the traces.png file

again right click/eliminar or delete key on keyboard

Now you'll see the outline.png file we imported as well (it was behind the traces.png from the start)

i used the same settings to convert the curves from this image as well.

let's repeat the process to delete the unnesesary objects

ungroup the ouline curves.

delete the outline of the image

delete the ouline.png bit map from the stock to leave only the curves.

close the vectorization tools window bi clickig "Cerrar" close button

this step is completly optional but it helps a lot when dealing with larger pcbs files.

let's create new layers for all of the curve groups we will need.

first click on the "capas" layer tab at the bottom of the screen

set a color to the layer

click on the black rectangle (it will change depending on what color you choose)

i found extremely handy to give diferent colors ot every layer.

change the curves to their respective layer

click to the respective curve or set of curves (holding shift while clicking you can selesct multiple).

right click/mover a capa/"selecciona la capa" right click/move to layer/"choose the layer"

now let's hide the outline clicking on the lightbulb over the desired layer

click and drag to select the rest of the curve (that will be our traces).

move them to the layer.

at the end it should look like this

Now it's time to manually create the offsets to the traces.

right click on the layer of the traces

choose:"Seleccionar los vectores para la capa" so select all of the curves within that layer.

go to the drawing tools tab at the bottom.

under the "desplazar y posicionar" orient category you should see "desplazar los vectores seleccionados" offset the selected curves button.

the offset tool settings

***since, we're using a 0.2mm endmill the minimum offset should be 50% of the diameter or 0.1mm lower than that will be a waste of time and bigger will not have smooth finish.

now it's a good time to create one layer for each offset.

with the curves selected "click derecho/mover a capa/nueva capa..." right click/move to layer/new layer...

new layer on the go.

choose a name and a color to each layer.

and repeat the steps from the *** mark on this tutorial.

until you have the offsets you like to process.

i've found 3 offsets to be more than enough to get a nice result (this will depend on your soldering skills though) more than that i belive is a waste of time lower than that you're more prone to make solder bridges on the smaller components like the MCU.

once you're done doing the offsets. you're ready to star to calculate the operations needed to generate de the Gcode. from the picture below

Let's jump to the CAM tab on the right side of the screen "trayectorias de herramientas" or toolpath generation tools tab.

Let's pin the tab on the workspace otherwise is a pain in the neck to loose that window every time you put your mouse on the curves.

the pin button is on the upper right side of the tab.

from here you can make a "vector like" toolpath for carving or cutting your boaards (for this example that's the only thing we'll be using.)

but we can also do a "raster-like" carving called pocketing

holes with a drilling operation

open curves carving (used in sign making with a V-bit ussually)

3D roughening and 3D finishing operations (when working with 3D models instead of bitmaps or 2D dxf files)

Click on the "trayectoria de herramienta de perfil" button in the pictue above.

let's make the cuting operation first.

the numbers on the picture above correspond to the numbers on the following list

select the curve you want to process with this operation.
define the final depth of the cut. (in this case i want all of the stock to be cutted)
select your cutter (i have presetted my 1mm endmill you can the the parameter in the picture below)
define where you want the operation to be made (on,over or under the curve) and the direction conventional or climb (i've found this settings to be the ideal.)
name and calculate (set a name that will be using for the output file.) and remember to set a proper safe height (10 mm in my case)

the setting on the cutting endmill

after that it shoul look like in the picture above.

now let's hide the outline curve on the leftside clicking the lightbulb and hide the operation by clicking onthe selection box on the right side of the screen on the operation we just made (on the toolpath category).

and select te first set of curves to process with another cam operation.

again right click on the layer and "seleccionarlos vectores para la capa" to select every curve on that layer with one click

again click on this operation

the numbers on the picture above correspond to the numbers on the following list

select the curve you want to process with this operation.
define the final depth of the cut. (in this case i want 0.2mm wich ussually is the depth of the copper layer on the pcb.)
select your cutter (i have presetted my 0.2mm endmill you can the the parameter in the picture below)
define where you want the operation to be made (on,over or under the curve) and the direction conventional or climb (i've found this settings to be the ideal.)
name and calculate (set a name that will be using for the output file.) and remember to set a proper safe height (10 mm in my case)

The settings on the traces endmill

Now, let's duplicate this same operation to the other offsets.

right click "duplicar" button to duplicate

repeat this until you have one CAM operation for each layer of offsets you've made.

in my case i have 3 offsets and the original set called "traces".

double click on the respective offset CAM operation.

select all of the respective curves for each offset layer. like in the picture above.

again,right click on the layer and "seleccionar los vectores para la capa"

once you have done all of the offsets CAM operations it should look like in the picture above all selected at once

This is completly optional but i've found really handy to merge all of this operations in a single one to generate jus 1 file of traces and 1 file of outline. (one for each endmill used.)

click on the "crear una trayectoria combinada" button to merge the selected toolpaths.

Select only the toolpaths you'll want to merge. like in the picture.

and give them a name for the final output file.

it should look like this (the merged toolpath is under the undividual cam operation that)

this is the merged operation selected.

aditionally we can stimate how much time will be using the Roland machine. select "tiempo estimado de mecanizado" button.

on "velc. rapida" set 240mm/seg that's the rapid speed when it's no carve.

Also optionally you can simulate the operation.

just click on the "preestrenar trayectorias" button.

Select the check box on every CAM operation you want to simulate.

click on "preestrenar trayectoria seleccionada" button to play the simulation

this is the simulation of the CAM

finally click on the "Guardar trayectoria de herramienta" button to save the g-code from every operation.

select the "Roland (mm)(*rol)" option under postprocessor and click on "guardar " button to save

Select a location to every file for the roland.

Finally this is the comparison between the two postprocessors

HERE you can download the Vcarve generated roland files

HERE You can download the vcarve editable file.

timelaps if an isp cutting

Make an in circuit programmers

Prepare the machine

Set your sacrificial layer

In order to save the roland to cut on the machine bed is necesary to make a sacrificial layer to place the PCB on and cut through MDF instead of Steel. That’s why i made my own sacrificial layer. The PCBS we have in the lab are 100X100X1.5 mm in dimesions so i cut out two 9 mm MDF about 100x100mm and glue them together using som PVA glue. Then place them in top of the machining bed using some double sided tape.

So since i used PVA glue and double sided tape i altered the new machining Surface and don’t know if it will be flat enough. Therefore i flatten out the Surface using the following method.

Set your zero on the sacrificial layer (method 1)

First i placed a 3 mm endmill on the SRM-20, place the machining Surface to flatten out. Opened the Factory software from Roland called VPANEL so i could guide the cutter to the desired place to start the cut.

The origin of this cut will start on the lower left corner like in the figure. Then clicked on the X/Y button on the right side of the VPANEL window in order to create a user origin for my piece.

Then with some help of a Little piece of Bond paper i placed between the endmill and the Surface of the MDF i started to jog the Z axis in X10 increments so i could’nt damage the tip of the endmill and stopped until felt some fricction on the paper. Then i was time to make click on Z button on the right side of the VPANEL window in order to create a user origin on Z in order to tell the SRM-20 where start cutting from.

2.2.- flatten your sacrificial layer

I did not had time to use some fancy CAD skills on this cut so i used the Factory software that came with the SRM-20 called iModela creator. Wich is a really basic (and a Little crappy CAD tool) from this software you can draw some basic figures like circles, rectangles and stars and by right clicking in it’s properties you can set the position and dimensions of the figures. I only use this software to flatten the sacrificial layer so i only draw a square and made it 100x100 and place it in the lower left corner of the drawing Surface. Then set the thicknes of the material. And the depth of the engraved cut operation.finally i clicked on the cut button where i set the tool diameter to 3mm and the type of material for this case i used the Wood (balsa) settings because is soft enough.

iModela workbench

setting the geometry dimensions

setting the dimensions on the material

Then checked the milling parameter but set it to default. And clicked on update origin to tell imodela where i put the user origins on the VPANEL finally i clicked on “CUT” button in the lower left corner of the screen.

WARNING

you only should do this if you already done the origin settings before otherwise you’ll end up hurting the endmill, the machine or yourself.

At the end of that operation you’ll end up with a completly flat Surface to work on your PCB traces and outlines.

2.3.- set your blank PCB board

now you have a flat Surface to work with, first you’ll need to clean your PCB blank board with some IPA (isopropil alcohol) to get rid of the dust and grease, other wise it will be harder once it is all cut out. Then place it on top of the sacrificial layer using some double sided tape in the side without copper.finally changed the cutter to a 60° “V” cutter.

2.4.-set your zeros on the PCB. (method 2)

Now, the copper is a nice conductive Surface and your cutter is made of som Steel alloy although Steel is’nt a good conductive it’ll be enough for some continuity tests with a multimeter. So grab a multimeter and place it on continuity test attach the end of a double alligator clamp to the copper Surface and the other end to one of the terminal on the multimeter. Now clip the cutting tool with other alligator clamps and the attache the end of that to the other terminal on the multimeter to closet he circuit. Start jogging the Z axis until the you hear the buzzer from the multimeter sound now that’s more comfortable than the paper method and more precise but you’ll always have to remember to unclip the aligators from the copper and the cutting tool otherwise you’ll end up hurting the machine or yourself. So, click on the Z button on the right side of the VPANEL window to create a new origin for this tool.

clamping the multimeter on the tool and the surface

on the left the multimeter shows OL (open line), on the right it show a value of about 3 ohms it means you have touched the copper on the machine

WARNING

Make sure that your multimeter handtools and alligator clamps are outside the machine before start cuttin otherwise you’ll end up damagin something.

Now, you are ready to start cutting traces. Click on the “CUT” buttton on the lower right side of the VPANEL window. Click on “Delete all” button to erase all of the previous Works with the machine. Click on “add” and then select your .rml file i’ve created using Fabmodules.

And then click on “output” to start the machining.

the machine is done change the cutting tool to the 3mm endmill again and used the multmeter method to set a new Z axis origin. Then again click on cut/delete all/add/select the file /output to start cutting the outlines of the FabISP.