This DeskProto tutorial shows you how to
machine a bust of Abraham Lincoln. CNC specialist NC-Techniek in the Netherlands
has ample experience, as you can see here, and kindly offered us the use of
their machine for a video shoot. This can of course be used for any person’s
bust: a politician, a movie star, sportsman or woman, your CEO, even your grandmother.
On the internet you can find many fine geometries, this one was bought at CGTrader dot com So, let me start DeskProto to create
the toolpaths for this Abe Lincoln statue. We are at the start screen.
I want to use the wizard for this project. Here is the wizard.
First check if your machine is correct, this will be the machine that you
selected when installing DeskProto. For this statue we need the Rotary machining wizard. First thing (as always) is load the geometry file.
It is listed here: Abe Lincoln dot stl You can see here: a nice statue. The width of the shoulders is
the largest width of this statue. Well, my wood is 144 millimeters wide, so I want to take that as maximum size, for X
as in this orientation X is this width of the shoulders. So here we are: 144,
the other axes will be scaled uniformly. Now I need to align the statue
with the rotation axis: that is twice 90 degrees will do the job. Here we are: nicely aligned. This one needs to be checked.
I can show you what happens if I don’t check it: as you can see: here is the rotation axis,
here is my geometry. This is not what we want. So I want to have the geometry centered
around the rotation axis. That’s it for this wizard page. I can continue to the
next page, which is about the material block and the supports. My material block is
a bit larger than the bounding box of the material that is displayed here.
So I’ll set it to custom and enter the correct dimensions: 250 millimeters
for the X-axis (the length of my block). It automatically makes the
support blocks a bit longer. Diameter as well is a bit larger: 150 millimeters. Next thing is the support blocks:
this one is OK, this one, where the part will
be connected to my rotation axes table, needs to be a bit larger, so I’ll set it to custom.
Go to detail settings, and I can either graphically adjust, or in this
case I’ll do it using keyboard. Now I can enter 30 and minus 30 in all directions
in order to have a nice cylinder support tab of 60 millimeters diameter: here we are,
sixty millimeters diameter. The zero block (point!): here, it’s on the rotation axis
on the left side of the block: that is okay. And my machining depth needs to be half of the
diameter, so in this case 75 millimeters is okay. Next: roughing operation.
I want to do roughing with a six millimeter ballnose cutter, so I can keep
the selected cutter in place. Feedrate is okay, Spindle speed is not:
for wood I want to use the maximum spindle speed of my machine: 24,000 rpm. The roughing skin needs to be
1 millimeter, to be removed during finishing, and my layer thickness needs to be 10 millimeters. Okay, Next, to the finishing page. Finishing will be done with a smaller
cutter, obviously, for more detail: 3 millimeter diameter, here as well 24,000 rpm.
And Next. And I do not yet want to calculate toolpaths
or save toolpaths in a file because some finishing details need
to be set in the operation parameters that are not present in the wizard.
So, the part parameters are okay, nothing needs to be done here: scaling, rotation,
material block, all has been entered in the wizard, so that’s all okay.
In the operations we need to make some changes. First for roughing. The strategy:
it says toolpaths along the X-axis, I want my toolpath to go around, to have
a rotating block, and I want to them to start on the far side of the geometry,
to keep as much material connected to the rotary axis table as possible.
So I’ll select around A-axis reversed. Roughing is okay. The area: I want my Area a bit smaller.
Here we are: the area to be machined. I’ll simply make it a bit smaller on both ends.
That’s the Area to be machined. No changes for the Borders.
I want to make the Free movement height a bit higher: just for a safety precaution.
And in the advanced parameters I have one setting: here, in the extra Start and End commands.
At the start of the file I can add a movement to Y=0.
As normally rotation axis toolpaths do not contain any Y-axis movements – now this one is
added at the start of the file, to make sure that the cutter moves to a position
exactly above the rotation axis. Okay, these are the roughing settings.
Here are the finishing settings: Same change for the strategy: around A-axis reversed.
Nothing here. Also: this one needs to be smaller even, as I do not
want my three millimeter cutter to machine the vertical surface below the statue,
so here I am for the finishing operation. No borders, movement, advanced:
here again the Y=0 command edit, OK, here also OK. Now I’ve done all settings that I need,
and I can start calculating the toolpaths, which will take some time,
so I’ll feel free to get myself a coffee. And here we are:
very many toolpaths. You can see the finishing
which closely follows the geometry and the roughing which goes down
in a number of layers of 10 millimeters each. For the finishing we can zoom in a bit,
see: many toolpaths are present. Here is an undercut:
the cutter cannot reach within the nose of Mr. Lincoln. Here is the second one: below the chin.
However, these do not matter as the resulting statue will be great anyway. So, here are all toolpaths,
and the last thing to do is to save the NC file which for my machine is a dot ISO file.
It can be dot TAP or any other extension, it depends on which machine you have selected. OK, Abe, and you will see that two files are
(the first roughing and then the finishing which of course is much larger),
two files are saved, as this machine does not have an automatic tool changer. So, already we can go to the milling machine. Well, after we machined the geometry,
we decided that a socle with some text on it would be nice, as our block is large enough.
We forgot to add that when originally creating the toolpaths,
so we’ll just add the socle now. We reopened the project, and what I want to
do is make this support block a bit larger to make it a socle and then
project some text on it. So, in the part parameters I go to the support
and I edit the left tab as I want to make that larger: not 30 but 60 millimeter
to make it 120 millimeters diameter. So we double the size, that’s okay,
and for X we’ll also add 30 millimeters to the left to double that as well.
Here we are. When I apply you can see the larger
support block, which has now become socle. Well, we also need to make
the block of material bit larger as DeskProto cannot calculate
toolpaths outside of the block. So for material: it’s now from 0 to 250,
and here I enter minus 30 as well. Here we are: so now we have a nice socle
that we can use to project the text on. Well, to read the text
I have to use this one, which is load a vector file,
the text has been prepared in a vector file. Here it is, in a certain font,
and here we are “Abe Lincoln”. That’s the text I want to be projected on the base.
So the first thing I need to do is rotate it, and that can be done in the part parameters.
As you can see now a new selection has been added: instead of just the geometry settings
there are also vector settings, with different tabs, and here are the
transformations for the vector data. So this is the rotation I meant: minus 90
degrees. It will keep warning me. Here we are. Just get it here.
So it’s now nicely wrapped around my cylinder. However, it has to move downward a bit
to get it on the socle. That’s the next change in the vector settings: For X (vertical: this is the X-axis as
you can see) minus 140 millimeters, and here we are: Abe Lincoln.
The text has been nicely positioned where we want it. Okay, now in order to create toolpaths
we need to add a vector operation. These two are both geometry operations,
but for vector data we need to use a vector operation. Here we are,
and in a vector operation I can select the machining depth, the cutter, and for
the machining depth I want to show you how I have calculated that. Bottom view, here we are.
Now I have to say to show look here: this one is the diameter of the material block
which was 150 millimeter, so the radius is 75. This is the support block
diameter: 120, so Z value is 60. Well, the machining depth of a
vector operation is from the top of the block, so this is minus 15,
and when I want to machine one millimeter deep I need to enter minus 16 millimeters, which is what we can do right here:
Z-setting is minus sixteen millimeters, okay. A smaller tool: for the text I want to use
one millimeter diameter tool: the thick cutter cannot enter into all characters. These settings I just did,
and for the text I want to use pocketing. Pocketing means removing all material inside a closed contour. I want to use all closed contours.
So let’s see what happens when we calculate toolpaths (not for these operations,
only for the vector operation). Calculate toolpaths: Yes,
here we are. Now I can see that layers are used:
roughing layers, which is obviously not needed here as
all material has been removed already. However, I can’t switch them off as
this is the first vector operation of this part. So what I do is use a trick:
I copy this vector operation. Copy. I call that one ‘Text’ and this one will be called ‘Dummy’.
This is an operation that we will not use. I make it invisible.
And now, as this is the second vector operation, I can switch off ‘Use layers’,
and when I calculate toolpaths now I don’t see anything – which makes sense
as the toolpaths are one millimeter deeper than the geometry. So when I switch off the
geometry (double-click, switch off the geometry) here I see the toolpaths.
However, these are not very nice for text. I want to use a different strategy
(I should have done that in first place). Instead of parallel toolpaths I want to
use offset toolpaths. And when I now say okay:
these are the toolpaths that I want to use for my text. And these are nicely one millimeter below the surface (as I can show you this way: when I also now show the geometry
not rendered but as wireframe) you can see: here is the geometry, and the
toolpaths are nicely one millimeter below the geometry. So okay, here we are,
back to the rendered geometry. And in fact I’m all done now.
I can write these toolpaths to an NC file. That doesn’t matter because we
enter the material one millimeter anyway. OK, and I say Abe-text
(oops, one too many). And now we go, again back to the milling machine