Week 7

Hi, Still here but starting to give uo so let's make this quickly. This week is about

CNC machining

, yes, that machine that has a drill head and cut trough wood, we are using this machine to make larger scale projects.

cnc image

This machine has almost the same bases as a 3D printer or a laser cutter. And obviously we need a software to interact with the machine, in this case we will be using:

VCarve pro

VCarve image

We are done setting the material click on, accept and we will have a 2D view of the material and a 3D view of the material. Then we can start importing the files we will work with. My favorite file for this kind of projects are DXF, so, I will not go deeper on the type of files you use, lets use this one.

Importing the files

Just import them

Maybe this is on he group website but...

Let's mention that our machine works with circular tools, so we can not make straight cuts, that's we have to make like a bone shape. This will, allow you to get closer to a corner ad assembly some pieces.
dog bones
There are a few steps we have to follow in order to make this dog bones,
First we have to make all the lines of my piece a single line, for this we use the Join lines tool.
Once we have the piece as a single line, we have to look for the dog bone tool on the left side menu. In spanish it is called "chaflán". In the options it gives us we are looking for the "cabeza de femur" option, then we have to give the diameter of the cut. This measure is the half diameter of my tool, for this task we are working with a 14 inch tool. So in this case 1/8 take it to mm.
Now take into account, which edges should have this extra cut, every inner edge or assembly edge. Once done selecting the edges let's go to the next step.

Every day tools

In case we need it, duplicate the pieces and move, scale, rotate it, etc

What can we do?

1st

Now let's go to the funny part, on he right side menu there is the menu with what can I do.
imagen del menu derecha

The first option, and the most used tool os the "perfil" I don't know how to say it in english, this is literally going all the side to cut the edge of the material.
The first parameter is depth, where I'm I going to start and where do I finish (talking about depth). The final depth should be the thickness of my material, however it is recommendable to go a little deeper just in case there is a irregularity on the material and make sure it goes completely through the material.
imagen de los parametros de profundidad

3nd

In the second menu we have to select the tool we will be working with, there are some default tools but we can create our own tools.
I don't have to, but if we select the edit option we can set some important parameters, like: Click on accept and there we go.
parametros de la herrmienta

3th

Going to the next step, Where do I want the tool to go through?
Here we have 3 options, In the kind of project we are working on it is not recommendable to select the "over" because it will cut material we need. For the outside lines, select the first option and for the inner lines select the second one. That's the easy way. por donde pasa la herramienta

4th

The last part of the cutting process we have to create some "pestañas" so the material doesn't ends on the other side of the lab and no one results hurt. This things are little bridges to keep the piece in it's place, so make sure this are slim enough to cut it with our hands. So the recommended measures are:
depth = 1.5 mm and length = 5mm. Once introduced de sizes click on "edit pestañas" and put the moue directly over the lines and add them manually,
Or you can ask the program to place them for you, however check them because this "pestañas" on the edges are not recommendable, always on straight lines. Click on accept and calculate and accept.

What happened next?

It will just open the 3D view with some blue, green and red lines. blue lines, where the machine will cut
green lines, where the machine will go deeper
red lines, the machine moving in the air
So we can preview what will it do.

3D preview

And next?

We have to select the left lines that will have the same parameters and repeat the previous steps.

Infilling the cutting

At least that's how I would call this tool, I don't know the name in english.
This as the name says, infills the cut,, the second option, literally the box.
Here we have 2 options, the first one and the second one, ahahahahahahahahahahahahahahaha No, the first one will make concentric forms until everything is filled.
The second one will make straight lines until is completely filled.
NOTE, don't forget to set the depth.

What else?

Many things, explore them by yourself

Is that it?

Noup, we have to export the file, just clock on the button: save trajectory and select a postprocessor, this will translate what we made on the software to instructions the machine can understand NOTE. in this fablab there are 2 machines, and each one has different things let's call them the black one and the red one. FOr the black one we will use: MACH2/3 ARC in mm/s For the red one, we don't know. Once selected the processor, save the trajectory, with save everything in a single file. (In case everything is cut wth the same tool size.) If we hav to change tool, select the trajectories with the same tool and save them as a file, select the other trajectories with the same size and save them.

NOTE, the file will be a txt file, where every line has commands like

Let's go to the machine

The machine is an Asia robotica,

Honestly the head was bigger than I thought, and it was easier to change the nozzel than I taught.
We used a 1/4 drill with 2 flutes, this means the diameter and the amount of "cut spikes" of the drill.

They looked something like this.
May be this is in the group website but I have to mention it, the way of taking out the drill is with two wrenches, the head has the spinning cylinder and the support of the drill, you have to position the first wrench on the spinning cylinder to stop it from rotate, and with the second wrench, take out the drill and the drill holder.

Note, make sure to hold the drill before it falls, because it might break,

Starting to cut

We already have the file in a way the machine can read it, we have to go for the material and place it on the bed of the machine. To secure them there are a metal pieces on the sides of the bed


Perfect, now we can configure the machine, for this we have to turn the machine on by releasing the emergency button and push the green button next to it.

Just like in the video, to turn it of just press the big red button.
Once clicked the buttons the machine will start thinking and it will show a question on the screen of the control.

What I learned

First of all, on Vcarve ALWAYS run the preview of the cut, if not, the machine will not do the cuts. So always preview.
Then, as you add cuts to your program on Vcarve there will be appearing layers on the right side of the window, this layers are not the order of the cuts, As on the laser you can set what to do first by placing those layers, Not here, the process should be, inner cuts and then the edge cuts. And you can set them by exporting the layers on different files and follow the order manually. Then, ON the machine, As this machine has metal plates to fix the wood on the sides, you have to take that distance into account, I set the origin of the machine very close t the wood edge, and the drill broke because it crashed with the fix plates. So remember, on the software, set the pieces as close to the origin edge as possible and leave some space on the other side for the plates. Now, on the machine set the origin of the machine OUT of the margin of the plates, this way everything will be alright. The just keep an eye on the machine if it is getting to close to the edges you can pause it or stop it.

No he terminado esta parte