Basic CAM.

[GWIZ]

Just some basics of what the CAM talk is about.
(computer-aided manufacturing)

This link has some of the boring history............
http://www.gsd.harvard.edu/inside/cadcam/whatis.htm

Basically a program that allows you to enter dimensions from a drawing, specify tools and material then the program will compute the math and tool-paths, spit out a program that a CNC uses to machine a part.


==
Picture 1)
Lets say someone gives you this drawing for you to machine on a CNC.
Note, to make the math harder the Hex is rotated 15º

Picture 2)
Just a 3D view of what the finished part should look like.
Basically machining the Hex on the block.

Picture 3)
A three axis CNC mill needs X,Y,Z coordinates to machine a part. The Z spindle depth is self explanatory.
If I had to machine the Hex without any help from a computer I would have to mathematically calculate each "starting" and "end" point, X, Y coordinates.

You would need to calculate the X, Y of P1 (the start) then calculate the X,Y of P2, note it has to be touching L1 and L2 ( that would be tangent to the two lines L1, L2) and calculating all the other X,Y points P1 through P7 finishing the Hex at P7.

Just to say it,
None of this tool-path math is on the basic drawing.
Stop and think how you would figure out where P2 is and all you have on the drawing is a 15º rotated Hex with a 3-1/2" radius. then the time involved to do the math.

If needed to make two passes a rough and finish pass, you would have to do all the math again leaving .010 for a finish pass to take off.
At that time it was faster to find a re-sharpened end-mill about .020 under size and run that first then run a full size cutter for the finish, that would save the time of calculating a second pass.

With CAD a computer-drafting program, locating the points would be fairly easy but we are on the subject of CAM that is geared to do the math and spit-out X, Y, Z coordinates that a CNC uses.


These first three drawings were made by TurboCad Not the CAM program I will be talking about.
Its two different animals.

[GWIZ]

This CAM program is not a substitute for a regular CAD program like the TurboCAD I use for making drawings.

Now the CAM program.

I found this Free software on the net and that is what I will be showing.
Gsimple
http://www.gsimple.eu/download.html

I would advise you to download everything on the site, I'm under the impression the person may not continue it any more.
Download the manual separately (it is not included with the program).
Also save all the Exercises to a folder.

I briefly went through the software so I may not get it's operation 100% right. only enough to explain Basic CAM and output a CNC program.

Picture 1)
Is just a screen shot and the buttons that I will be using.

Picture 2)
Clicking on the "Block" button allows us define a block of material.
I entered
X 8"
Y 8"
Z 1"
That's the size of the block on the print not adding the 1/4" for the hex.

I changed the "Block Material" to Aluminum, Note the Material Group number (7.1) you will need to select 7.1 when we get to defining the cutting tools.

Click OK and you should see a green square.

Picture 3)
Now move the mouse to the green square and click it, It should turn red, that selects the "Block" so we can set a Hex on top.
Click onto the "Polygonal Bulge" button.

We enter,

No. of edges = 6
3.5" Radius = 3.5"
Height = .250

Center
X 4"
Y 4"
That places the Hex in the center of the 8" square block.

Click OK

Picture 4)
We have to turn the Hex 15º
Select the Hex with your mouse, it will change color.
Click the "Turn" button and enter,

X 4"
Y 4" (that is the Hex's Center)
The Angle shows 90º add 15º,
and we enter 105º

Click OK.

Picture 5)
The View buttons
Isometric view.

Note, you are only allowed to create objects in the "Top View" orientation

[allessence]

Thanks for posting this up. I'm going to try it later today when I get back from work.


Will this allow for us to make 3D drawing to post up as well?

[dubby]

Thanks G... I'd come across that one a while back before I got the new laptop and it didn't make the migration. Never played with it much but I just spent hte last few minutes tinkering and it looks good.

Won't let me load my .dxf files into it though, they may be a little more complex than it wants or I may have something screwed up. Will keep tinkering

[allessence]

Thanks, My object looked just like yours.

How would be add texture?

[GWIZ]

Originally Posted by allessence

Will this allow for us to make 3D drawing to post up as well?

For posting the CAM pictures I used the "Print Screen" key that is on your computers key board.

Its not what you think, it will be very limited for drawings, check out the link below for TurboCad.

Originally Posted by allessence

Thanks, My object looked just like yours.

How would be add texture?

Your welcome.
I don't think you can add texture.

I guess I should have mentioned the first three drawings were made by TurboCad Not the CAM program I'm demonstrating.
http://www.shopfloortalk.com/forums/...ad.php?t=18123

TurboCad kind of works the same but is geared for making drawings. TurboCad will NOT make a CNC program.

I will be adding to the CAM lessons, cutting tools, materials, tool-path and the CNC output program.

[GWIZ]

Creating/adding a "Tool Data Base" Inventory and Defining tool cutting parameters.

Originally the Software was written for metric and the default tools are metric, some of the tools do not have materials associated with them and if you use them without association you will get a "Unsuitable" remark error.

Picture 1)
Click the "Tool" tab and select End Mills / Rough.
We will be using 3/4" endmills.....the rest is Self explanatory.
Enter the rest of the data.

Note, I added "hss" to the name so I know it's a high speed end mill, when you add to the Inventory list Carbide can be noted with another tool with the appropriate RPM and feeds for carbide.

Click OK

Picture 2)
now we have to associate the material data.
move the mouse over the tool you just created and click/select it,
then click the "Mat. Data" tab
Click the "add" tab
Scroll down to 7.1 and select it with your mouse

Remember at the beginning we selected Aluminum for our block and the 7.1 showed up as the group.
Eventually you will have to associate all the different materials/groups you will be cutting to each tool.

Enter the data.

1500 RPM
F horz 15 ..........as in 15 Inches per minute.
F plunge 10 ......as in 10 ipm.
Cut. depth .750

Click OK.

(2 flute endmill, 1500 rpm, 15 ipm, comes out to a ~.005 chip load for aluminum).

Note, we assigned Aluminum because that is the material we selected for our "Block" at the start.
again, eventually you will need to ADD parameters for Steel, SS, Copper, Plastic.........to the same cutting tool.

The parameters for tools are saved.
selecting a material in the beginning "block" so the program will automatically use the speeds and feeds you associated with the tool and material.

*** The Software seems to like a rough and finishing tool. ******
Go back above and repeat the steps and add a fine endmill into the Tool Inventory.
Click the "Tool" tab and select End Mills / Fine.


Picture 3)
That is just a screen shot of the other 3/4" endmills I added, each will have a different RPM and feed rate Assigned.
hss, carbide, 2fl, 4fl........

We will only need one 3/4"rough and one fine endmill for now.

[TONYL]

A good cam system can take the place of cad software. The hex example that you descriped can be done with 2 mouse clicks in MasterCam along with any type of drafting as well as solid modeling.

Tony

[GWIZ]

Originally Posted by TONYL

A good cam system can take the place of cad software. The hex example that you descriped can be done with 2 mouse clicks in MasterCam along with any type of drafting as well as solid modeling.

Tony

What does MasterCam cost ?

[dubby]

Originally Posted by GWIZ

What does MasterCam cost ?

Yup... I found out the answer to that one last year. It is an awesome program though and if you have a spare copy laying around you want to trade for some fishing lures, gimme a call